1721 lines
85 KiB
TeX
1721 lines
85 KiB
TeX
\documentclass[12pt,a4paper]{report}
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\begin{document}
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\begin{center}
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\begin{huge}
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TRICS--Reference Manual \\
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\end{huge}
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Version November, 1998\\
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Dr. Mark K\"onnecke \\
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Labor f\"ur Neutronenstreuung\\
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Paul Scherrer Institut\\
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CH--5232 Villigen--PSI\\
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Switzerland\\
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\end{center}
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\clearpage
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\clearpage
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\tableofcontents
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\clearpage
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% html: Beginning of file: `trics.htm'
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\chapter{The Four Circle Diffractometer TRICS}
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\label{f0}
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\section{Introduction}
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The four circle diffractometer TRICS is used for the study of crystal structures
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by neutron diffraction at single crystals. TRICS can be operated in two
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modes: 1.) with a single counter very much like a traditional four circle
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diffractometer and 2.) with three position sensitive detectors operating
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like a oscillation camera as used by protein crystallographers. The second
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option has not yet been implemented due to the unavailability of suitable
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detectors and electronics. This manual describes the operation of TRICS
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using the SICS software.
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TRICS is situated at one of the beamlines for hot neutrons at the spallation
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source SINQ at PSI, Switzerland. The incident beam first hits a
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monochromator crystal. The selected wavelength is in principle fixed. A
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monochromator lift with two monochromators and the possiblity to select
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different reflections for diffraction at the monochromator however make it
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possible to select between a few different neutron wavelength. The sample is
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held in a standard eulerian cradle with the usual angles omega, chi and phi.
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Up to three position sensitive detectors are held on a detector holder at
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different angles in two theta. Or a single detector is fixed to this setup.
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The three position sensitive detectors may be moved up and down on a sphere
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around the sample. This allows to access different lattice planes when the
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eulerian cradle has been replaced by some cryostat or other sample
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environment devices to heavy to be used in conjunction with an eulerian
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cradle.
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The control of a four circle diffractometer requires a tight integration
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between measurement procedures and specialized data anlaysis software. For
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the actual control of the instrument, its movements and the actual
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measurement of reflections the SICS software is provided. Preliminary data
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analysis and special four circle calculations are done with a set of F77
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programs. These are mostly programs which originate from the ILL, France.
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Given this setup the rest of this manual logically has to have three parts:
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\begin{itemize}
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\item A general part (cf.\ Section~\ref{f1}) describing the principal
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operation of the SICS software.
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\item A chapter describing the operation of TRICS with a
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single counter (cf.\ Section~\ref{f2}).
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\item A chapter describing the operation of TRICS with
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position sensitive (cf.\ Section~\ref{f3})
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detectors.
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\end{itemize}
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% html: End of file: `trics.htm'
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% html: Beginning of file: `tricsgen.htm'
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\chapter{General Operation of the SICS instrument control software}
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\label{f1}
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This chapter contains information about:
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\begin{itemize}
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\item Basic SICS concepts (cf.\ Section~\ref{f4})
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\item Driving motors (cf.\ Section~\ref{f5})
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\item Configuring motor parameters (cf.\ Section~\ref{f6}).
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\item TRICS motor list (cf.\ Section~\ref{f7}).
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\item Counting and monitors (cf.\ Section~\ref{f8}).
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\item Sample Environment Device Control (cf.\ Section~\ref{f9}).
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\item Log I/O to a client logfile (cf.\ Section~\ref{f10}) at the server, all
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command output to a commandlog (cf.\ Section~\ref{f11}) or to your local
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machine using the open log file option in the File menu of the
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SICS command line client.
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\item Doing batch processing using batch files (cf.\ Section~\ref{f12}) or the LNS
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specific R\"unbuffer (cf.\ Section~\ref{f13}) system.
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\item {\bf Interrupt} SICS by hitting the interrupt button near the bottom of
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the SICS command line client.
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\item How to perform crystallographic computations (cf.\ Section~\ref{f14}) online.
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\item Some specialist commands for configuring certain aspects of your
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client connection (cf.\ Section~\ref{f15}) and for in depth interaction with
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the SICS server (cf.\ Section~\ref{f16}).
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\end{itemize}
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% html: End of file: `tricsgen.htm'
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% html: Beginning of file: `basic.htm'
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\section{Basic SICS concepts}
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\label{f4}
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\subsection{General structure}
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SICS is a client server system. The application the user sees is usually some form of client. A client has two tasks: the first is to collect user input and send it to the SICS server who will execute the command. The clients second task is to listen to the the server messages and display them in a readable format. This aoproach has two advantages: clients can reside on machines across the whole network thus enabling remote control from everywhere in the world. The second advantage is that new clients (such as graphical user interface clients) can be written in any feasible language without changes to the server.
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\subsection{SICS Command Syntax }
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SICS is an object oriented system. This is reflected in the command syntax. SICS objects can be devices such as motors or counters, variables such as wavelength or Title and measurement procedures. Communication with these objects happens by sending messages to the target object. This is very simply done by typing something like: object message par1 par2 .. parn. For example, if we have a motor called A1:\begin{verbatim}
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A1 list
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\end{verbatim}
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will print a parameter listing for the motor A1. In this example no parameters were needed. There exist a number of one-word commands as well. For
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compatability reasons some commands have a form which resembles a function call such as:\begin{verbatim}
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drive a1 26.54
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\end{verbatim}
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This will drive motor a1 to 26.54. All commands are
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ASCII-strings and usually in english. SICS is in general CASE INSENSITIVE.
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However, this does not hold for parameters you have to specify. On a unix
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system for instance file names are case sensitive and that had to be
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preserved. Commands defined in the scripting language are lower case by
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convention.
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\subsection{Authorisation}
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A client server system is potentially open to unauthorised hackers which might mess up the instrument and your valuable measurements. A known problem in instrument control is that less knowledgeable user accidentally change instrument adjustments which should better be left fixed. In order to solve these two problems SICS supports authorisation on a very fine level. As a user you have to specify a username and password in order to able to access SICS. Some clients already do this for you automatically. SICS support four levels of access to an instrument:
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\begin{itemize}
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\item {\bf Spy } may look at everything, request any value, but may not actually change anything. No damage potential here.
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\item {\bf User } is privileged to perform a certain amount of operations necessary to run the instrument.
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\item {\bf Manager } has the permission to mess with almost everything. A very dangerous person.
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\item {\bf Internal } is not accessible to the outside world and is used to circumvent protection for internal uses. However some parameters are considered to be so critical that they cannot be changed during the runtime of the SICS-server, not even by Managers.
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\end{itemize}
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All this is stated here in order to explain the common error message: You are not authorised to do that and that or something along these lines.
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\subsection{SICS variables}
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Most of the parameters SICS uses are hidden in the objects to which they belong. But some are separate objects of their own right and are accessible at top level. For instance things like Title or wavelength. They share a common syntax for changing and requesting their values. This is very simple: The command {\em objectname } will return the value, the command {\em objectname newvalue } will change the variable. But only if the authorisation codes match.
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\subsection{The SICS Command Line Client}
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The most common client for controlling SICS is the {\bf SICS command line
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client}.
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This application can be started by typing the command:
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\begin{verbatim}
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sics &
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\end{verbatim}
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at the Unix prompt. Before this program is ready to collaborate with you you
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have to connect it to an instrument using the options in the connect
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pulldown menu. The screen is roughly divided in three areas: The top area
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shows all input to and output from the server. The middle area shows the
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command history. At the lower end is a text entry field which allows to type
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commands to the SICS server. For more information about this client consult
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the online help of this application.
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% html: End of file: `basic.htm'
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% html: Beginning of file: `drive.htm'
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\section{Drive commands}
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\label{f5}
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Many objects in SICS are {\bf drivable }. This means they can run to a new value. Obvious examples are motors. Less obvious examples include composite adjustments such as setting a wavelength or an energy. This class of objects can be operated by the {\bf drive, run, Success } family of commands. These commands cater for blocking and non-blocking modes of operation.
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{\bf run var newval var newval ... } can be called with one to n pairs of object new value pairs. This command will set the variables in motion and return to the command prompt without waiting for the requested operations to finish. This feature allows to do things to the instrument while perhaps a slow device is running into position.
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{\bf Success } waits and blocks the command connection until all pending operations have finished (or an interrupt occured).
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{\bf drive var newval var newval ... } can be called with one to n pairs of object new value pairs. This command will set the variables in motion and wait until the driving has finished. A drive can be seen as a sequence of a run command as stated above immediatetly followed by a Success command.
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% html: End of file: `drive.htm'
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% html: Beginning of file: `motor.htm'
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\section{SICS motor handling}
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\label{f6}
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In SICS each motor is an object with a name. Motors may take commands which basically come in the form {\em motorname command }. Most of these commands deal with the plethora of parameters which are associated with each motor. The syntax for manipulating variables is, again, simple. {\em Motorname parametername } will print the current value of the variable. {\em Motorname parametername newval } will set the parameter to the new value specified. A list of all parameters and their meanings is given below. The general principle behind this is that the actual (hardware) motor is kept as stupid as possible and all the intracacies of motor control are dealt with in software. Besides the parameter commands any motor understands these basic commands:
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\begin{itemize}
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\item {\bf Motorname list } gives a listing of all motor parameters.
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\item {\bf Motorname reset } resets the motor parameters to default values.
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This is software zero to 0.0 and software limits are reset to hardware
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limits.
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\item {\bf Motorname position} prints the current position of the motor.
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\item {\bf Motorname interest} initiates automatic printing of any position
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change of the motor. This command is mainly interesting for implementors of
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status display clients.
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\end{itemize}
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Please note that the actual driving of the motor is done via the drive (cf.\ Section~\ref{f5}) command.
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\subsection{The motor parameters}
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\begin{itemize}
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\item {\bf HardLowerLim } is the hardware lower limit. This is read from the motor controller and is identical to the limit switch welded to the instrument. Can usually not be changed.
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\item {\bf HardUpperLim } is the hardware upper limit. This is read from the motor controller and is identical to the limit switch welded to the instrument. Can usually not be changed.
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\item {\bf SoftLowerLim } is the software lower limit. This can be defined by the user in order to restrict instrument movement in special cases.
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\item {\bf SoftUpperLim } is the software upper limit. This can be defined by the user in order to restrict instrument movement in special cases.
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\item {\bf SoftZero } defines a software zero point for the motor. All further movements will be in respect to this zeropoint.
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\item {\bf Fixed } can be greater 0 for the motor being fixed and less
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or equal than zero for the motor being movable.
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\item {\bf InterruptMode } defines the interrupt to issue when the motor fails. Some motors are so critical for the operation of the instrument that all operations shall be stopped when there is a problem. Other are less critical. This criticallity is expressed in terms of interrupts, denoted by integers in the range 0 - 4 translating into the interrupts: continue, AbortOperation, AbortScan, AbortBatch and Halt. This parameter can usually only be set by managers.
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\item {\bf Precision } denotes the precision to expect from the motor in positioning. Can usually only be set by managers.
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\item {\bf AccessCode } specifies the level of user privilege necessary to operate the motor. Some motors are for adjustment only and can be harmful to move once the adjustment has been done. Others must be moved for the experiment. Values are 0 - 3 for internal, manager, user and spy. This parameter can only be changed by managers.
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\item {\bf Speed }, defunct.
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\item {\bf Sign } allows to reverse the operating sense of the motor. For cases where electricians and not physicists have defined the operating sense of the motor. Usually a parameter not to be changed by ordinary users.
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\end{itemize}
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% html: End of file: `motor.htm'
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% html: Beginning of file: `trimot.htm'
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\section{TRICS Motors}
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\label{f7}
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This chapter has still to be defined as there is a war waging in LNS about
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names. Final names will be entered after the end of hostilities. More then
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one name may be stated as SICS supports aliases. For now,
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you have to do with:
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\begin{itemize}
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\item OM = A3 = omega motion of the eulerian cradle.
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\item CH = chi circle of the eulerian cradle.
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\item PH = phi circle of the eulerian cradle
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\item TH = A4 = two theta angle of the detector.
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\end{itemize}
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% html: End of file: `trimot.htm'
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% html: Beginning of file: `counter.htm'
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\section{SICS counter handling}
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\label{f8}
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This section deals with the SICS interface to single counters.
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Where the SICS counter concept may include several monitors per
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counter. A counter is, again, a named object which takes commands.
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A word or two has to be lost about the SICS handling of preset values for counters.
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Two modes of operation have to be distinguished: counting until a timer has passed,
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for example: count for 20 seconds. This mode is called timer mode. In the other
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mode, counting is continued until a control monitor has reached a certain
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preset value. This mode is called Monitor mode. The preset values in Monitor
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mode are usually very large. Therefore the counter has an exponent data variable.
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Values given as preset are effectively 10 to the power of this exponent. For
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instance if the preset is 25 and the exponent is 6, then counting will be
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continued until the monitor has reached 25 million. Note, that this scheme with
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the exponent is only in operation in Monitor mode.
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The commands understood are:
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\begin{itemize}
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\item {\bf countername SetPreset val } sets the counting preset to val.
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\item {\bf countername GetPreset } prints the current preset value.
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\item {\bf countername SetExponent val } sets the exponent for the counting
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preset in monitor mode to val.
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\item {\bf countername GetExponent } prints the current exponent used
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in monitor mode.
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\item {\bf countername SetMode val } sets the counting mode to val. Possible values are Timer for timer mode operation and Monitor for waiting for a monitor to reach a certain value.
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\item {\bf countername GetMode } prints the current mode.
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\item {\bf countername GetCounts } prints the counts gathered in the last run.
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\item {\bf countername GetMonitor n } prints the counts gathered in the monitor number n in the last run.
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\item {\bf countername Count preset } starts counting in the current mode and the the preset preset.
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\item {\bf countername status } prints a message containing the preset and
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the current monitor or time value. Can be used to monitor the progress of
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the counting operation.
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\item {\bf countername gettime } Retrieves the actual time the counter
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counted for. This excludes time where there was no beam or counting was
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paused.
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\item {\bf countername getthreshold m} retrieves the value of the threshold
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set for the monitor number m.
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\item {\bf countername setthreshold m val} sets the threshold for monitor m
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to val. WARNING: this also makes monitor m the active monitor for evaluating
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the threshold. Though the EL7373 counterbox does not allow to select the
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monitor to use as control monitor in monitor mode, it allows to choose
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the monitor used for pausing the count when the count rate is below the
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threshold (Who on earth designed this?)
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\end{itemize}
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% html: End of file: `counter.htm'
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% html: Beginning of file: `samenv.htm'
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\section{ Sample Environment Devices}
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\label{f9}
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\subsection{SICS Concepts for Sample Environment Devices}
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\label{f9:concept}
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SICS can support any type of sample environment control device if there is a
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driver for it. This includes temperature controllers, magnetic field controllers
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etc. The SICS server is meant to be left running continously. Therefore there
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exists a facility for dynamically configuring and deconfiguring environment
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devices into the system. This is done via the {\bf EVFactory} command.
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It is expected that instrument scientists will provide command procedures or
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specialised R\"unbuffers for configuring environment devices and setting
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reasonable default parameters.
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In the SICS model
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a sample environment device has in principle two modes of operation. The first
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is the drive modus. The device is monitored in this modus when a new value for it
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has been requested. The second modus is the monitor modus. This modus is entered
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when the device has reached its target value. After that, the device must be
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continously monitored throughout any measurement. This is done through the
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environment monitor or {\bf emon}. The emon understands a few commands of its
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own.
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Within SICS all sample environement devices share some common behaviour
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concerning parameters and abilities. Thus any given environment device
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accepts all of a set of general commands plus some additional commands
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special to the device.
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In the next section the EVFactory, emon and the general commands understood
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by any sample environment device will be discussed. This reading is mandatory
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for understanding SICS environment device handling. Then there will be another
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section discussing the special devices known to the system.
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\subsection{SampleEnvironment Error Handling}
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A \label{f9:error}sample environment device may fail to stay at its preset value during a
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measurement. This condition will usually be detected by the emon. The question
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is how to deal with this problem. The requirements for this kind of error
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handling are quite differntiated. The SICS model therefore implements several
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strategies for handling sample environment device failure handling.
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The strategy to use is selected via variable which can be set by the user for
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any sample environment device separatetly. Additional error handling strategies
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can be added with a modest amount of programming. The error handling strategies currently
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implemented are:
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\begin{description}
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\item[Lazy] Just print a warning and continue.
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\item[Pause] Pauses the measurement until the problem has been resolved.
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\item[Interrupt] Issues a SICS interrupt to the system.
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\item[Safe] Tries to run the environment device to a value considered safe by the
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user.
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\end{description}
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\subsection{General Sample Environment Commands}
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\label{f9:general}
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\subsubsection{EVFactory}
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EVFactory is responsible for configuring and deconfiguring sample environment
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devices into SICS. The syntax is simple:
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\begin{description}
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\item[EVFactory new name type par par ...] Creates a new sample environment device. It will be known to SICS by the
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name specified as second parameter. The type parameter decides which driver to
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use for this device. The type will be followed by additional parameters
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which will be evaluated by the driver requested.
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\item[EVFactory del name] Deletes the environment device name from the system.
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\end{description}
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\subsubsection{emon}
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The environment monitor emon takes for the monitoring of an environment device
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during measurements. It also initiates error handling when appropriate. The emon
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understands a couple of commands.
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\begin{description}
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\item[emon list] This command lists all environment devices currently registered in the
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system.
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\item[emon register name] This is a specialist command which registers the environment device name
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with the environment monitor. Usually this will automatically be taken care
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of by EVFactory.
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\item[emon unregister name] This is a specialist command which unregisters the environment device name
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with the environment monitor. Usually this will automatically be taken care
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of by EVFactory Following this call the device will no longer be monitored and
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out of tolerance errors on that device no longer be handled.
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\end{description}
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\subsubsection{General
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Commands UnderStood by All Sample Environment Devices}
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\label{f9:all}
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Please note that each command discussed below MUST be prepended with the name
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of the environment device as configured in EVFavtory!
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The general commands understood by any environment controller can be subdivided
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further into parameter commands and real commands. The parameter commands just
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print the name of the parameter if given without an extra parameter or
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set if a parameter is specified. For example:
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\begin{quotation}
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Temperature Tolerance\end{quotation}
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prints the value of the variable Tolerance for the environment controller
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Temperature.
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\begin{quotation}
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Temperature Tolerance 2.0\end{quotation}
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sets the parameter Tolerance for Temperature to 2.0. Parameters known to ANY
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envrironment controller are:
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\begin{description}
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\item[Tolerance] Is the deviation from the preset value which can be tolerated before an
|
|
error is issued.
|
|
\item[ Access] Determines who may change parameters for this controller.
|
|
Possible values are:
|
|
\begin{itemize}
|
|
\item 0 only internal
|
|
\item 1 only Managers
|
|
\item 2 Managers and Users.
|
|
\item 3 Everybody, including Spy.
|
|
\end{itemize}
|
|
\item[LowerLimit] The lower limit for the controller.
|
|
\item[UpperLimit] The upper limit for the controller.
|
|
\item[ErrHandler.] The error handler to use for this controller. Possible values:
|
|
\begin{itemize}
|
|
\item 0 is Lazy.
|
|
\item 1 for Pause.
|
|
\item 2 for Interrupt
|
|
\item 3 for Safe.
|
|
\end{itemize}
|
|
For an explanantion of these values see the section about error (cf.\ Section~\ref{f9:error}) handling
|
|
above.
|
|
\item[ Interrupt] The interrupt to issue when an error is detected and Interrupt error
|
|
handling is set. Valid values are:
|
|
\begin{itemize}
|
|
\item 0 for Continue.
|
|
\item 1 for abort operation.
|
|
\item 2 for abort scan.
|
|
\item 3 for abort batch processing.
|
|
\item 4 halt system.
|
|
\item 5 exit server.
|
|
\end{itemize}
|
|
\item[SafeValue] The value to drive the controller to when an error has been detected and
|
|
Safe error handling is set.
|
|
\end{description}
|
|
|
|
Additionally the following commands are understood:
|
|
\begin{description}
|
|
\item[send par par ...] Sends everything after send directly to the controller and return its
|
|
response. This is a general purpose command which allows to manipulate controllers
|
|
and controller parameters directly. The protocoll for these commands is
|
|
documented in the documentation for each controller. Ordinary users should
|
|
not tamper with this. This facility is meant for setting up the device with
|
|
calibrartion tables etc.
|
|
\item[ list] lists all the parameters for this controller.
|
|
\item[ no command, only name.] When only the name of the device is typed it will return its
|
|
current value.
|
|
\item[ name val ] will drive the device to the new value val. Please note that the same
|
|
can be achieved by using the drive command.
|
|
\item[ name log on] Switches logging on. If logging is on, at each cycle in the emon the
|
|
current value of the environment variable will be recorded together with a
|
|
time stamp. Be careful about this, for each log point a bit of memory is
|
|
allocated. At some time the memory is exhausted! Log clear frees it again
|
|
and log frequency (both below) allows to set the logging time intervall.
|
|
\item[ name log off] Switches logging off.
|
|
\item[name log clear] Clears all recorded time stamps and values.
|
|
\item[name log gettime] This command retrieves a list of all recorded time stamps.
|
|
\item[name log getval] This command retrieves all recorded values.
|
|
\item[name log getmean] Calculates the mean value and the standard deviation for all logged
|
|
values and prints it.
|
|
\item[name log frequency val] With a parameter sets, without a parameter requests the logging intervall
|
|
for the log created. This parameter specifies the time intervall in seconds
|
|
between log records. The default is 5 minutes. A value of 0 means a record any
|
|
cycle of the SICServer.
|
|
\end{description}
|
|
|
|
\subsection{Special Environment Control Devices}
|
|
|
|
|
|
|
|
This section lists the parameters needed for configuring a special environment
|
|
device into the system and special parameters and commands only understood by
|
|
that special device. All of the general commands listed above work as well!
|
|
|
|
\subsubsection{ITC-4 and ITC-503 Temperature Controllers}
|
|
|
|
\label{f9:itc4}
|
|
|
|
These temperature controller are fairly popular at SINQ. It is manufactured by
|
|
Oxford Instruments. At the back side of this controller there is a RS-232
|
|
socket which must be connected to a Macintosh computer running the SINQ
|
|
terminal server program via a serial cable. Please make sure with a different
|
|
Macintosh or a PC that the serial line is OK and the ITC-4 responding before
|
|
plugging it in.
|
|
|
|
\paragraph{ITC-4 Initialisation}
|
|
|
|
|
|
An ITC-4 can be configured into the system by:
|
|
\begin{quotation}
|
|
EVFactory new Temp ITC4 computer port channel\end{quotation}
|
|
This creates an ITC-4 controller object named Temp within the system. The
|
|
ITC-4 is expected to be connected to the serial port channel at the
|
|
Macintosh computer computer running the SINQ terminal server program
|
|
listening at port port. For example:
|
|
\begin{quotation}
|
|
EVFactory new Temp ITC4 lnsp22.psi.ch 4000 6\end{quotation}
|
|
connects Temp to the Macintosh named lnsp22, serial port 5 (6 above is no typo!),
|
|
listening at port 4000.
|
|
|
|
\paragraph{ITC-4 Additional Parameters}
|
|
|
|
|
|
The ITC-4 has a few more parameter commands:
|
|
\begin{description}
|
|
\item[timeout] Is the timeout for the Macintosh terminal server program waiting for
|
|
responses from the ITC-4. Increase this parameter if error messages
|
|
containg ?TMO creeping up.
|
|
\item[ sensor] Sets the sensor number to be used for reading temperature.
|
|
\item[ control] Sets the control sensor for the ITC-4. This sensor will be used
|
|
internally for regulating the ITC-4.
|
|
\item[divisor] The ITC4 does not understand floating point numbers, the ITC-503 does.
|
|
In order to make ITC4's read and write temperatures correctly floating point
|
|
values must be multiplied or divided with a magnitude of 10. This parameter
|
|
determines the appropriate value for the sensor. Is usually 10 for a sensor
|
|
with one value behind the comma or 100 for a sensor with two values after
|
|
the comma.
|
|
\item[multiplicator] The same meaning as the divisor above, but for the control sensor.
|
|
\end{description}
|
|
|
|
\paragraph{Installing an ITC4 step by step}
|
|
|
|
|
|
\begin{enumerate}\item Connect the ITC temperature controller to port 6 on the Macintosh
|
|
serial port extension box. Port 6 is specially configured for dealing with
|
|
the ideosyncracies of that device. No null modem is needed.
|
|
\item Install the ITC4 into SICS with the command: \newline
|
|
evfactory new name Macintoshname 4000 7\newline
|
|
Thereby replace name with the name you want to address the ITC4 in SICS. A
|
|
good choice for a name is temperature, as such a value will be written to data files.
|
|
Please note, that SICS won't let you use that name if it already exists. For
|
|
instance if you already had a controller in there. Then the command:\newline
|
|
evfactory del name \newline
|
|
will help. Macintoshname is the name of the instrument Macintosh PC.
|
|
\item Configure the upper and lowerlimits for your controller appropriatetly.
|
|
\item Figure out which sensor you are going to use for reading temperatures.
|
|
Configure the sensor and the divisor parameter accordingly.
|
|
\item Figure out, which sensor will be used for controlling the ITC4. Set the
|
|
parameters control and multiplicator accordingly. Can be the same as the
|
|
sensor.
|
|
\item Think up an agreeable temperature tolerance for your measurement. This
|
|
tolerance value will be used 1) to figure out when the ITC4 has reached its
|
|
target position. 2) when the ITC4 will throw an error if the ITC4 fails to
|
|
keep within that tolerance. Set the tolerance parameter according to the
|
|
results of your thinking.
|
|
\item Select one of the numerous error handling strategies the control
|
|
software is able to perform. Configure the device accordingly.
|
|
\item Test your setting by trying to read the current temperature.
|
|
\item If this goes well try to drive to a temperature not to far from the
|
|
current one.
|
|
\end{enumerate}
|
|
|
|
\paragraph{ITC-4 Trouble Shooting}
|
|
|
|
|
|
If the ITC-4 {\bf does not respond at all}, make sure the serial connection to
|
|
the Macintosh is working. Use standard RS-232 debugging procedures for doing
|
|
this. The not responding may also come up as a failure to connect to the ITC-4
|
|
during startup.
|
|
|
|
If error messages containing the string {\bf ?TMO} keep creeping up followed
|
|
by all signs of command not understood, then increase the timeout. The standard
|
|
timeout of 10 microseconds is to short at times.
|
|
|
|
You keep on reading {\bf wrong values} from the ITC4. Mostly off by a
|
|
factor 10. Then set the divisor correctly. Or you may need to choose a
|
|
decent sensor for that readout.
|
|
|
|
Error messages when {\bf trying to drive the ITC4}. These are usually the
|
|
result of a badly set multiplicator parameter for the control sensor.
|
|
|
|
The ITC4 {\bf never stops driving}. There are at least four possible
|
|
causes for this problem:
|
|
\begin{enumerate}
|
|
\item The multiplicator for the control sensor was wrong and the ITC4 has now
|
|
a set value which is different from your wishes. You should have got error
|
|
messages then as you tried to start the ITC4.
|
|
\item The software is reading back wrong temperature because the sensor and
|
|
divisor parameters are badly configured. Try to read the temperature and if
|
|
it does have nothing to do with reality, set parameters accordingly.
|
|
\item The tolerance parameter is configured so low, that the ITC4 never
|
|
manages to stay in that range. Can also be caused by inappropriate PID
|
|
parameters in the ITC4.
|
|
\item
|
|
You are reading on one sensor (may be 3) and controlling on another one (may
|
|
be 2). Then it may happen that the ITC 4 happily thinks that he has reached
|
|
the temperature because its control sensor shows the value you entered as
|
|
set value. But read sensor 3 still thinks he is far off. The solution is to
|
|
drive to a set value which is low enough to make the read sensor think it is
|
|
within the tolerance. That is the temperature value you wanted after all.
|
|
\end{enumerate}
|
|
|
|
\subsubsection{Haake Waterbath Thermostat}
|
|
|
|
\label{f9:haake}
|
|
|
|
This is sort of a buck full of water equipped with a temperature
|
|
control system. The RS-232 interface of this device can only be operated at
|
|
4800 baud max. This is why it has to be connected to the serial printer port
|
|
of the Macintosh serial port server computer. This makes the channel number to
|
|
use for initialisation a 1 always. The driver for this device has been
|
|
realised in the Tcl extension language of the SICS server. A prerequisite
|
|
for the usage of this device is that the file hakle.tcl is sourced in the
|
|
SICS initialisation file and the command inihaakearray has been published.
|
|
Installing the
|
|
Haake into SICS requires two steps: first create an array with
|
|
initialisation parameters, second install the device with evfactory. A
|
|
command procedure is supplied for the first step. Thus the initialisation
|
|
sequence becomes:
|
|
\begin{quotation}
|
|
inihaakearray name-o-array macintosh-computer name port channel\newline
|
|
evfactory new temperature tcl name-of-array\end{quotation}
|
|
An example for the SANS:
|
|
\begin{quotation}
|
|
inihaakearray eimer lnsp25.psi.ch 4000 1 \newline
|
|
evfactory new temperature tcl eimer\end{quotation}
|
|
Following this, the thermostat can be controlled with the other environment
|
|
control commands.
|
|
|
|
The Haake Thermostat understands a single special subcommand: {\bf sensor}.
|
|
The thermostat may be equipped with an external sensor for controlling and
|
|
reading. The subcommand sensor allows to switch between the two. The exact
|
|
syntax is:
|
|
\begin{quotation}
|
|
temperature sensor val\end{quotation}
|
|
val can be either intern or extern.
|
|
|
|
\subsubsection{Dilution Cryostat}
|
|
|
|
\label{f9:dilu}
|
|
|
|
This is a large ancient device for reaching very low temperatures. This
|
|
cryostat can be configured into SICS with the command:
|
|
\begin{verbatim}
|
|
EVFactory new Temp dillu computer port channel table.file
|
|
\end{verbatim}
|
|
Temp is the name of the dilution controller command in SICS, dillu is the
|
|
keyword which selects the dilution driver, computer, port and channel are
|
|
the parameters of the Macintosh-PC running the serial port server program.
|
|
table.file is the fully qualified name of a file containing a translation
|
|
table for this cryostat. The readout from the dilution controller is a
|
|
resistance. This table allows to interpolate the temperature from the
|
|
resistance measurements and back. Example:
|
|
\begin{verbatim}
|
|
evfactory new temperature dillu lnsp19.psi.ch 4000 1 dilu.tem
|
|
\end{verbatim}
|
|
installs a new dilution controller into SICS. This controller is connected
|
|
to port 1 at the Macintos-PC with the newtwork adress lnsp19.psi.ch. On this
|
|
macintosh-PC runs a serial port server program listening at TCP/IP port
|
|
4000. The name of the translation table file is dilu.tem.
|
|
|
|
The dilution controller has no special commands, but two caveats: As of
|
|
current (October 1998) setting temperatures does not work due to problems
|
|
with the electronics. Second the dilution controller MUST be connected to
|
|
port 1 as only this port supports the 4800 maximum baud rate this device
|
|
digests.
|
|
|
|
\subsubsection{Bruker Magnet Controller B-EC-1}
|
|
|
|
\label{f9:bruker}
|
|
|
|
This is the Controller for the large magnet at SANS. The controller is a
|
|
box the size of a chest of drawers. This controller can be operated in one
|
|
out of two modes: in {\bf field} mode the current for the magnet is controlled via
|
|
an external hall sensor at the magnet. In {\bf current} mode, the output current
|
|
of the device is controlled. This magnet can be configured into SICS with a
|
|
command syntax like this:
|
|
\begin{quotation}
|
|
evfactory new name bruker Mac-PC Mac-port Mac-channel\end{quotation}
|
|
|
|
name is a placeholder for the name of the device within SICS. A good
|
|
suggestion (which will be used throughout the rest of the text) is magnet.
|
|
bruker is the keyword for selecting the bruker driver. Mac-PC is the name of
|
|
the Macintosh PC to which the controller has been connected, Mac-Port is the
|
|
port number at which the Macintosh-PC's serial port server listens.
|
|
Mac-channel is the RS-232 channel to which the controller has been
|
|
connected. For example (at SANS):
|
|
\begin{verbatim}
|
|
evfactory new magnet bruker lnsp25.psi.ch 4000 9
|
|
\end{verbatim}
|
|
|
|
creates a new command magnet for a Bruker magnet Controller connected to
|
|
serial port 9 at lnsp25.
|
|
In addition to the standard environment controller commands this magnet
|
|
controller understands the following special commands:
|
|
\begin{description}
|
|
\item[magnet polarity] Prints the current polarity setting of the controller. Possible
|
|
answers are plus, minus and busy. The latter indicates that the controller
|
|
is in the process of switching polarity after a command had been given to
|
|
switch it.
|
|
\item[magnet polarity val] sets a new polarity for the controller. Possible values for val are
|
|
{\bf minus} or {\bf plus}. The meaning is self explaining.
|
|
\item[magnet mode] Prints the current control mode of the controller. Possible
|
|
answers are {\bf field} for control via hall sensor or {\bf current} for
|
|
current control.
|
|
\item[magnet mode val] sets a new control mode for the controller. Possible values for val are
|
|
{\bf field} or {\bf current}. The meaning is explained above.
|
|
\item[magnet field] reads the magnets hall sensor independent of the control mode.
|
|
\item[magnet current] reads the magnets output current independent of the control mode.
|
|
\end{description}
|
|
|
|
Warning: There is a gotcha with this. If you type only magnet a
|
|
value will be returned. The meaning of this value is dependent on the
|
|
selected control mode. In current mode it is a current, in field mode it is
|
|
a magnetic field. This is so in order to support SICS control logic.
|
|
You can read values at all times explicitly using magnet current or
|
|
magnet field.
|
|
|
|
\subsubsection{The CryoFurnace.}
|
|
|
|
\label{f9:ltc11}
|
|
|
|
The CryoFurnace at PSI is equipped with a Neocera LTC-11 temperature
|
|
controller. This controller can control either an heater or an analag output
|
|
channel. Futhermore a choice of sensors can be selected for controlling the
|
|
device. The LTC-11 behaves like a normal SICS environment control device
|
|
plus a few additional commands. An LTC-11 can be configured into SICS with
|
|
the following command:
|
|
\begin{quotation}
|
|
evfactory new name ltc11 Mac-PC Mac-port Mac-channel\end{quotation}
|
|
|
|
name is a placeholder for the name of the device within SICS. A good
|
|
suggestion is temperature.
|
|
ltc11 is the keyword for selecting the LTC-11 driver. Mac-PC is the name of
|
|
the Macintosh PC to which the controller has been connected, Mac-Port is the
|
|
port number at which the Macintosh-PC's serial port server listens.
|
|
Mac-channel is the RS-232 channel to which the controller has been
|
|
connected. For example (at DMC):
|
|
\begin{verbatim}
|
|
evfactory new temperature ltc11 lnsp18.psi.ch 4000 6
|
|
\end{verbatim}
|
|
|
|
creates a new command magnet for a LTC-11 temperature Controller connected to
|
|
serial port 6 at lnsp18.
|
|
|
|
The additional commands understood by the LTC-11 controller are:
|
|
\begin{description}
|
|
\item[temperature sensor ] allows to query the current sensor used for temperature readout.
|
|
\item[temperature sensor val ] allows to select the sensor val for temperature readout.
|
|
\item[temperature controlanalog ] allows to query the sensor used for controlling the analog channel.
|
|
\item[temperature controlanalog val ] allows to select the sensor val for controlling the analog channel.
|
|
\item[temperature controlheat ] allows to query the sensor used for controlling the heater channel.
|
|
\item[temperature controlheat val ] allows to select the sensor val for controlling the heater channel.
|
|
\item[temperature mode] Allows to query if the LTC-11 controls the analog or heater channel.
|
|
\end{description}
|
|
|
|
Further notes: As the CryoFurnace is very slow and the display at the
|
|
controller becomes unusable when the temperature is read out to often, the
|
|
LTC-11 driver buffers the last temperature read for 5 seconds. Setting the
|
|
mode of the LTC-11 is possible by computer, but not yet fully understood and
|
|
therefore unusable.
|
|
|
|
\subsubsection{The Eurotherm Temperature Controller}
|
|
|
|
\label{f9:euro}
|
|
|
|
At SANS there is a Eurotherm temperature controller for the sample heater.
|
|
This and probably other Eurotherm controllers can be configured into SICS
|
|
with the following command. The eurotherm needs to be connected with a
|
|
nullmodem adapter.
|
|
\begin{quotation}
|
|
evfactory new name euro Mac-PC Mac-port Mac-channel\end{quotation}
|
|
|
|
name is a placeholder for the name of the device within SICS. A good
|
|
suggestion is temperature.
|
|
euro is the keyword for selecting the Eurotherm driver. Mac-PC is the name of
|
|
the Macintosh PC to which the controller has been connected, Mac-Port is the
|
|
port number at which the Macintosh-PC's serial port server listens.
|
|
Mac-channel is the RS-232 channel to which the controller has been
|
|
connected. {\bf WARNING:} The eurotherm needs a RS-232 port with an unusual
|
|
configuration: 7bits, even parity, 1 stop bit. Currently only the SANS
|
|
Macintosh port 13 (the last in the upper serial port connection box) is
|
|
configured like this! Thus, an example for SANS and the name temperature
|
|
looks like:
|
|
\begin{verbatim}
|
|
evfactory new temperature euro lnsp25.psi.ch 4000 13
|
|
\end{verbatim}
|
|
|
|
There are two further gotchas with this thing:
|
|
\begin{itemize}
|
|
\item The eurotherm needs to operate in the EI-bisynch protocoll mode. This has
|
|
to be configured manually. For details see the manual coming with the machine.
|
|
\item The weird protocoll spoken by the Eurotherm requires very special control
|
|
characters. Therefore the send functionality usually supported by a SICS
|
|
environment controller could not be implemented.
|
|
\end{itemize}
|
|
|
|
% html: End of file: `samenv.htm'
|
|
% html: Beginning of file: `logbook.htm'
|
|
|
|
\section{LogBook command}
|
|
|
|
\label{f10}
|
|
|
|
Some users wish like to have all the input typed to SICS and all responses
|
|
collected in a file for further review. This is implemented via the LogBook
|
|
command. LogBook understands the following syntax:
|
|
\begin{description}
|
|
\item[ LogBook] alone prints the name of the current logfile and the status of event
|
|
logging.
|
|
\item[ LogBook file filename] This command sets the filename to which output will be printed.
|
|
Please note that this new filename will only be in effect after restarting
|
|
logging.
|
|
\item[ LogBook on] This command turns loggin on. All commands and all answers will be
|
|
written to the file defined with the command described above. Please note,
|
|
that this command will overwrite an existing file with the same name.
|
|
\item[ LogBook off] This command closes the logfile and ends logging.
|
|
\end{description}
|
|
|
|
% html: End of file: `logbook.htm'
|
|
% html: Beginning of file: `commandlog.htm'
|
|
|
|
\section{The Commandlog}
|
|
|
|
\label{f11}
|
|
|
|
The commandlog is a file where all communication with clients
|
|
having user or manager privilege is logged. This log allows to retrace each
|
|
step of an experiment. This log is usually switched off and must be
|
|
configured by the instrument manager. There exists a special command,
|
|
commandlog, which allows to control this log file.
|
|
\begin{description}
|
|
\item[commandlog new filename] starts a new commandlog writing to filename. Any prior files will be
|
|
closed. The log file can be found
|
|
in the directory specified by the ServerOption LogFileDir. Usually this is
|
|
the log directory.
|
|
\item[commandlog] displays the status of the commandlog.
|
|
\item[commandlog close] closes the commandlog file.
|
|
\item[commandlog auto] Switches automatic log file creation on. This is normally switched on.
|
|
Log files are written to the log directory of the instrument account. There
|
|
are time stamps any hour in that file and there is a new file any 24 hours.
|
|
\end{description}
|
|
|
|
% html: End of file: `commandlog.htm'
|
|
% html: Beginning of file: `macro.htm'
|
|
|
|
\section{Macro Commands}
|
|
|
|
\label{f12}
|
|
|
|
SICS has a built in macro facility. This macro facility is aimed at instrument managers and users alike. Instrument managers may provide customised measurement procedures in this language, users may write batch files in this language. The macro language is John Ousterhout's Tool Command Language (TCL). Tcl has control constructs, variables of its own, loop constructs, associative arrays and procedures. Tcl is well documented by several books and online tutorials, therefore no details on Tcl will be given here. All SICS commands are available in the macro language. Some potentially harmful Tcl commands have been deleted from the standard Tcl interpreter. These are: exec, source, puts, vwait, exit,gets and socket. The following commands allow access to the macro facility:
|
|
|
|
{\bf FileEval name } tries to open the file name and executes the script in this file. Please note that the server is configured via such a file.
|
|
|
|
{\bf ClientPut sometext1 ... } writes everything after ClientPut to the client which started the script. Useful for output to a client from macro scripts.
|
|
|
|
{\bf SICSType object } allows to query the type of the object specified by object. Possible return values are
|
|
\begin{itemize}
|
|
\item {\bf DRIV } if the object is a SICS drivable object such as a motor
|
|
\item {\bf COUNT } if the object is some form of a counter.
|
|
\item {\bf COM } if the object is a SICS command.
|
|
\item {\bf NUM } if the object is a number.
|
|
\item {\bf TEXT } if object is something meaningless to SICS.
|
|
\end{itemize}
|
|
|
|
{\bf SICSbounds var newval } checks if the new value newval lies within the limits for varaible var. Returns an error or OK depending on the result of the test.
|
|
|
|
{\bf SICSStatus var } SICS devices such as counters or motor may be started and left running while the program is free to do something else. This command allows to enquire the status of such a running device. Return values are internal SICS integer codes. This command is only of use for SICS programmers.
|
|
|
|
{\bf SetStatus newval } allows to set the SICS status to one of: Eager, UserWait, Count, NoBeam, Driving, Running, Scanning, Batch Hatl or Dead. This command is only available in macros.
|
|
|
|
{\bf SetInt newval, GetInt } allow for the manipulation of interrupts from macro scripts. Not recommended! Possible return values or new values are: continue, abortop, abortscan, abortbatch, halt, free, end. This command is only permitted in macros. Should only be used by SICS programmers.
|
|
% html: End of file: `macro.htm'
|
|
% html: Beginning of file: `buffer.htm'
|
|
|
|
\section{R\"unbuffer Commands}
|
|
|
|
\label{f13}
|
|
|
|
LNS scientists have got used to using R\"unbuffers for instrument control. A R\"unbuffer is an array of SICS commands which typically represent a measurement. This R\"unbuffer can be edited at run time. This is very similar to a macro. In contrast to a macro only SICS commands are allowed in R\"unbuffers. When done with editing the R\"unbuffer it can be entered in a R\"unlist. This is a stack of R\"unbuffers which get executed one by one. While this is happening it is possible (from another client) to modify the R\"unlist and edit and add additional R\"unbuffer on top of the stack. This allows for almost infinite measurement and gives more control than a static batch file. In order to cater for this scheme three commands have been defined:
|
|
|
|
The {\bf Buf } object is responsible for creating and deleting R\"unbuffers. The syntax is:
|
|
\begin{itemize}
|
|
\item {\bf Buf new name } creates a new empty R\"unbuffer with the name name. name will be installed as a SICS object afterwards.
|
|
\item {\bf Buf copy name1 name2 } copies R\"unbuffer name1 to buffer name2.
|
|
\item {\bf Buf del name } deletes the R\"unbuffer name.
|
|
\end{itemize}
|
|
|
|
After creation, the R\"unbuffer is accessible by his name. It than understands the commands:
|
|
\begin{itemize}
|
|
\item {\bf NAME append what shall we do with a drunken sailor } will add all text after append as a new line at the end of the R\"unbuffer.
|
|
\item {\bf NAME print } will list the contents of the R\"unbuffer.
|
|
\item {\bf NAME del iLine } will delete line number iLine from the R\"unbuffer.
|
|
\item {\bf NAME ins iLine BimBamBim } inserts a new line {\bf after } line iLine into the R\"unbuffer. The line will consist of everything given after the iLine.
|
|
\item {\bf NAME subst pattern newval } replaces all occurences of pattern in the R\"unbuffer by the text specified as newval. Currently this feature allows only exact match but may be expanded to Unix style regexp or shell like globbing.
|
|
\item {\bf NAME save filename } saves the contents of the R\"unbuffer into file filename.
|
|
\item {\bf NAME load filename } loads the R\"unbuffer with the data in file filename.
|
|
\item {\bf NAME run } executes the R\"unbuffer.
|
|
\end{itemize}
|
|
|
|
The R\"unlist is accessible as object {\bf stack }. Only one R\"unlist per server is permitted. The syntax:
|
|
\begin{itemize}
|
|
\item {\bf stack add name } adds R\"unbuffer name to the top of the stack.
|
|
\item {\bf stack list } lists the current R\"unlist.
|
|
\item {\bf stack del iLine } deletes the R\"unbuffer iLine from the R\"unlist.
|
|
\item {\bf stack ins iLine name } inserts R\"unbuffer name after R\"unbuffer number iLine into the R\"unlist.
|
|
\item {\bf stack run } executes the R\"unlist and returns when all R\"unbuffers are done.
|
|
\item {\bf stack batch } executes the R\"unlist but does not return when done but waits for further R\"unbuffers to be added to the list. This feature allows a sort of background process in the server.
|
|
\end{itemize}
|
|
|
|
% html: End of file: `buffer.htm'
|
|
% html: Beginning of file: `hkl.htm'
|
|
|
|
\section{4 Circle Diffractometer Setting Calculation}
|
|
|
|
\label{f14}
|
|
|
|
An essential part of operating a 4 circle diffractometer is the calculation
|
|
of the setting angles for the diffractometer for a given reciprocal lattice
|
|
point from the UB matrix and the wavelength. SICS does this through the hkl
|
|
object. The hkl object can calculate the required settings both for normal 4
|
|
circle configuration and normal beam configuration. It is possible to
|
|
specify if low chi or high chi values are preferred. The wavelength can be
|
|
dealt with in two ways: it can be set manually. Or a variable controlling
|
|
the wavelength can be specified. The hkl object will then be updated
|
|
automatically with the newest value for the wavelength whenever the
|
|
wavelength changes.
|
|
|
|
The hkl object understands the following commands:
|
|
\begin{description}
|
|
\item[hkl list] Prints a listing of all relevant settings calculation parameters.
|
|
\item[hkl current] Prints the value of the last calculated reflection.
|
|
\item[hkl lambda val] Manually sets the wavelength to val. No automatic updates of the
|
|
wavelength will be performed.
|
|
\item[hkl lambdavar val] Sets the name of the variable controlling the wavelength. The wavelength
|
|
in the hkl object will be automatically updated whenever the wavelength is
|
|
modified by driving variable val. This is a user command because the TRICS
|
|
spectrometer has more then one monochromator.
|
|
\item[hkl setub a11 a12 a13 a21 a22 a23 a31 a 32 a33] SetUB sets the UB matrix to the nine values given.
|
|
\item[hkl nb val] Switches the mode for normal beam calculation. If val is 1 a normal beam
|
|
calculation is performed, else normal four circle calculations are done.
|
|
\item[hkl quadrant val] Defines the chi quadrant to prefer. The parameter val can be 0 for low
|
|
chi and 1 for high chi.
|
|
\item[hkl calc h1 h2 h3 psi hamil] Calculates and prints the setting angles for the reflection (h1,h2,h3).
|
|
Optionally a psi value and a hamilton position can be specified.
|
|
\item[hkl run h1 h2 h3 psi hamil] Calculates the setting angles for the reflection (h1,h2,h3) and starts
|
|
the motors to run to that position. This command will return immediately and
|
|
will not wait for the diffractometer to arrive at the setting angles
|
|
requested.
|
|
Optionally a psi value and a hamilton position can be specified.
|
|
\item[hkl drive h1 h2 h3 psi hamil] Calculates the setting angles for the reflection (h1,h2,h3) and starts
|
|
the motors to drive to that position. This command will wait for the
|
|
diffractometer to arrive at the setting angles requested.
|
|
Optionally a psi value and a hamilton position can be specified.
|
|
\end{description}
|
|
|
|
% html: End of file: `hkl.htm'
|
|
% html: Beginning of file: `config.htm'
|
|
|
|
\section{Configuration Commands}
|
|
|
|
\label{f15}
|
|
|
|
SICS allows to change the user rights of the current client server connection, control the amount of output a client receives and to specify additional logfiles where output will be placed. All this is accessed through the following commands:
|
|
|
|
The SICS server logs all its activities to a logfile, regardless of what the user requested. This logfile is mainly intended to help in server debugging. However, clients may register an interest in certain server events and can have them displayed. This facility is accessed via the {\bf GetLog } command. It needs to be stressed that this log receives messages from {\bf all } active clients. GetLog understands the following messages:
|
|
\begin{itemize}
|
|
\item {\bf GetLog All } achieves that all output to the server logfile is also written to the client which issued this command.
|
|
\item {\bf GetLog Kill } stops all logging output to the client.
|
|
\item {\bf GetLog OutCode } request that only certain events will be logged to the client issuing this command. Enables only the level specified. Multiple calls are possible.
|
|
\end{itemize}
|
|
Possible values for OutCode in the last option are:
|
|
\begin{itemize}
|
|
\item {\bf Internal } internal errors such as memory errors etc.
|
|
\item {\bf Command } all commands issued from any client to the server.
|
|
\item {\bf HWError } all errors generated by instrument hardware. The SICS server tries hard to fix HW errors in order to achieve stable operations and may not generate an error message if it was able to fix the problem. This option may be very helpful when tracking dodgy devices.
|
|
\item {\bf InError } All input errors found on any clients input.
|
|
\item {\bf Error } All error messages generated by all clients.
|
|
\item {\bf Status } some commands send status messages to the client invoking the command in order to monitor the state of a scan.
|
|
\item {\bf Value } Some commands return requested values to a user. These messages have an output code of Value.
|
|
\end{itemize}
|
|
|
|
{\bf config } allows to configure various aspects of the current client server connection. Basically three things can be manipulated: The connections output class, the user rights associated with it, and output files.
|
|
|
|
\begin{itemize} \item The command {\bf config OutCode val } sets the output code for the connection. By default all output is sent to the client. But a graphical user interface client might want to restrict message to only those delivering requested values and error messages and suppressing anything else. In order to achieve this, this command is provided. Possible values Values for val are Internal,Command, HWError,InError,Status, Error, Value. This list is hierarchical. For example specifying InError for val lets the client receive all messages tagged InError, Status, Error and Value, but not HWError, Command and Internal messages.
|
|
\item Each connection between a client and the SICS server has user rights assocociated with it. These user rights can be configured at runtime with the command {\bf config Rights Username Password }. If a matching entry can be found in the servers password database new rights will be set.
|
|
\item Scientists are not content with having output on the screen. In order to
|
|
check results a log of all output may be required. The command {\bf config
|
|
File name } makes all output to the client to be written to the file
|
|
specified by name as well. The file must be a file accessible to the server,
|
|
i.e. reside on the same machine as the server. Up to 10 logfiles can be
|
|
specified. Note, that a directly connected line printer is only a special
|
|
filename in unix.
|
|
\item {\bf config close num} closes the log file denoted by num again.
|
|
\item {\bf config list} lists the currently active values for outcode and user
|
|
rights.
|
|
\end{itemize}
|
|
|
|
|
|
% html: End of file: `config.htm'
|
|
% html: Beginning of file: `system.htm'
|
|
|
|
\section{System Commands}
|
|
|
|
\label{f16}
|
|
|
|
{\bf Sics\_Exitus }. A single word commands which shuts the server down. Only Managers may use this command.
|
|
|
|
{\bf wait time } waits time seconds before the next command is executed. This does not stop other clients from issuing commands.
|
|
|
|
{\bf ResetServer } resets the server after an interrupt.
|
|
|
|
{\bf Dir } a single word command which lists all objects available in the SICS system in its current configuration.
|
|
|
|
{\bf status } A single word command which makes SICS print its current
|
|
status. Possible return values can be:
|
|
Eager to execute commands, Scanning, Counting, Running, Halted. Note that if a command is executing which takes some time to complete
|
|
the server will return an ERROR: Busy message when further commands are issued.
|
|
|
|
{\bf status interest} initiates automatic printing of any status change in the
|
|
server. This command is primarily of interest for status display client
|
|
implementors.
|
|
|
|
{\bf backup file} saves the current values of SICS variables and selected
|
|
motor and device parameters to the disk file specified as parameter. The
|
|
path to this files is relative to the SICS server directory. The format
|
|
of the file is a list of SICS commands to set all these parameters again.
|
|
|
|
{\bf restore file} reads a file produced by the backup command described
|
|
above and restores SICS to the state it was in when the status was saved with
|
|
backup.
|
|
% html: End of file: `system.htm'
|
|
% html: Beginning of file: `tricsingle.htm'
|
|
|
|
\chapter{Running TRICS with a Single Counter}
|
|
|
|
\label{f2}
|
|
|
|
In this mode TRICS simulates a conventionell four circle diffractometer much
|
|
like a x-ray diffractometer as commercially available. The tasks which have
|
|
to be solved are:
|
|
\begin{itemize}
|
|
\item Locate Reflections
|
|
\item Index reflections and refine a UB-matrix.
|
|
\item Measure a couple of reflections.
|
|
\end{itemize}
|
|
|
|
\section{Locate Reflections}
|
|
|
|
|
|
|
|
If you know x-ray single crystal diffractometers you'll expect sophisticated
|
|
reflection search procedures here. Nothing is available in this field in
|
|
SICS. It was deemed inapropriate for neutron research. The first reflections
|
|
must be found by hand. Something which may help in this is a quick scan
|
|
facility which allows to run a motor and print counts while the motor is
|
|
moving. This can be invoked by a command like this:
|
|
\begin{verbatim}
|
|
susca var start end time
|
|
\end{verbatim}
|
|
The parameters are:
|
|
\begin{itemize}
|
|
\item var: the motor or variable to scan.
|
|
\item start: the start position from which to scan.
|
|
\item end: the end position for this scan.
|
|
\item time: The maximum counting time.
|
|
\end{itemize}
|
|
Be aware that this is inprecise and liable to changes in the source current.
|
|
But it may help to locate the aproximate position of a peak.
|
|
|
|
Once a peak has been found, its position can be optimised and centered with the
|
|
peak optimiser (cf.\ Section~\ref{f17}).
|
|
|
|
The next thing to do is to store the reflection and find other ones. Once a
|
|
few reflections have been found, the need to be written to disk. This can be
|
|
accomplished with the object rliste which has the following subcommands:
|
|
\begin{description}
|
|
\item[rliste clear] clears all entries from the list
|
|
\item[rliste store] saves the current diffractometer position into the list
|
|
\item[rliste write file] Writes the contents of the reflection list to the file specified.
|
|
\end{description}
|
|
|
|
\section{Indexing Reflections and Refining UB-Matrix}
|
|
|
|
|
|
|
|
For these purposes the external programs INDEX and
|
|
RAFIN are provided. These programs are courtesy of the ILL, France.
|
|
|
|
\section{Measuring Reflections}
|
|
|
|
|
|
|
|
Before measuring reflections a list of reflections to measure must be
|
|
created. This is done with the external program
|
|
HKLGEN. Then reflections this reflection list can
|
|
be fed into SICS using the mess (cf.\ Section~\ref{f19}) command. mess
|
|
creates two output files: a .col file containing the reflection profiles of
|
|
all the relfections and a .dat files which contains the
|
|
HKL,F,sig(F),TH,OM,CH,PH for each reflection. Intensity has then be
|
|
integrated within SICS. The .col files can be processed by the program
|
|
REFRED which allows to perform more advanced data reduction chores and has a
|
|
choice of integration methods for reflection data. Please note, that SICS
|
|
does not automatically measure standard reflections. It is your task to add
|
|
suitable standard reflections into the reflection list.
|
|
% html: End of file: `tricsingle.htm'
|
|
% html: Beginning of file: `optimise.htm'
|
|
|
|
\section{The Peak Optimiser}
|
|
|
|
\label{f17}
|
|
|
|
In instrument control the need arises to optimise a peak with respect to
|
|
several variables. Optimising means finding the maximum of the peak with
|
|
respect to several variables.
|
|
This is usefull during instrument calibration.
|
|
Four circle diffractometers use this facility on a day to day basis
|
|
for finding and verifying the exact position of reflections. In order to
|
|
support both usages a more general module has been implemented. The way of
|
|
operation is like this:
|
|
\begin{verbatim}
|
|
while errors gt precision and cycles lt maxcycles
|
|
for all variables
|
|
do a scan
|
|
Try find the maximum, two halfwidth points and the peak center.
|
|
if failure extend the scan.
|
|
if success shift the variable, remember last shift.
|
|
If shift lt precicison mark this variable as done
|
|
end for
|
|
end while
|
|
\end{verbatim}
|
|
Possible outcomes of this procedure are: success, the peak was lost or the
|
|
maximum number of cycles was reached. This routine requires that the
|
|
instrument is currently placed somewhere on the peak and not miles away.
|
|
|
|
The Peak Optimiser is implemented as an object with the name opti. It
|
|
understand the following commands:
|
|
\begin{description}
|
|
\item[opti clear] clears the optimiser.
|
|
\item[opti addvar name step nStep precision] This command adds a variable to optimise to the optimiser. The user has
|
|
to specify the name of the variable, the step width to use for scanning, the
|
|
number of steps needed to cover the full peak when scanning and the
|
|
precision which should be achieved when optimising the peak. The step width
|
|
and number of steps parameters should cover the whole peak. However, the
|
|
Optimiser will extend the scan is the specified range is not sufficient.
|
|
\item[opti run] Starts the optimiser. It will then optimise the peak. This may take some
|
|
time.
|
|
\end{description}
|
|
The behaviour of the optimiser can be configured by modifying some
|
|
parameters. The synatx is easy: {\bf opti parameter} prints the value of the
|
|
parameter, {\bf opti parameter newval} sets a new value for the parameter.
|
|
The following parameters are supported:
|
|
\begin{description}
|
|
\item[maxcycles] The maximum number of cycles the optimiser will run when trying to
|
|
optimise a peak. The default is 7.
|
|
\item[threshold] When a peak cannot be identified after a scan on a variable, the
|
|
optimiser will check if there is a peak at all. In order to do that it
|
|
searches for a count rate higher then the threshold parameter. If such a
|
|
rate cannot be found the optimiser will abort and complain that he lost the
|
|
peak.
|
|
\item[channel] The counter channel to use for scanning. The default is to use the
|
|
counter. By modifying this parameter, the optimiser can optimise on a
|
|
monitor instead.
|
|
\item[countmode] The counting mode to use when scanning. Possible values are {\bf timer} or
|
|
{\bf monitor}.
|
|
\item[preset] The preset value to use for counting in the scan. Depending on the
|
|
status of the countmode parameter this is either a preset time or a preset
|
|
monitor.
|
|
\end{description}
|
|
|
|
% html: End of file: `optimise.htm'
|
|
\section{External FORTRAN 77 Programs}
|
|
\subsection{INDEX}
|
|
|
|
The program indexes reflections on the basis of observed
|
|
2Theta, Omega, Chi, Phi angles when the cell constants and
|
|
wavelength are known.
|
|
It does not take into account systematic extinctions.
|
|
|
|
The process, when successful, has three steps.
|
|
|
|
First, it calculates, for each set of observations, all possible
|
|
HKL's for which theta(calc) lies within theta(obs) +/-
|
|
delta theta.
|
|
delta theta is given - see below -.
|
|
For delta theta = 0, the value defaults to 0.05.
|
|
|
|
Second, it finds for all combinations of two sets of observations,
|
|
the angle between the indexed HKL's for which angle(calc) lies
|
|
within angle (obs) +/- delta.
|
|
delta given - see below -. Delta = 0 causes default to 0.2
|
|
|
|
Finally, it finds all sets of indexed HKL's that explain all angles
|
|
between the observed sets of Omega, Chi and Phi.
|
|
|
|
The user will normally be presented with several possible sets of
|
|
HKL's which fit within the limits given.
|
|
- they are already tested for right-handedness -
|
|
and he must now choose which set he likes the most.
|
|
|
|
If he wishes he may now specify which set of reflections he likes
|
|
and the program will then set up the input file for the program
|
|
rafin, - see next section -.
|
|
The program ensures that the first two reflections are acceptable
|
|
to rafin. The user must say whether he wants the ub matrix
|
|
written directly into lsd ( for instant use ) and which file he
|
|
wants his rafin input to come from (usually rafin.dat).
|
|
The program rafin is then automatically started.
|
|
|
|
|
|
Input to index can be done either from the terminal or from a file
|
|
index.dat
|
|
The format is the same, an example is given here.
|
|
\begin{verbatim}
|
|
THIS IS A DUMMY EXAMPLE ( text )
|
|
5.82 16.15 4.09 90 103.2 90 .84 .15 (cell constants, lambda delta)
|
|
16.18 9.01 34.71 14.74 0 (2Th, Om, Ch, Ph, delta theta)
|
|
13.21 7.8 .71 -56.13 0.1 (2Th, Om, Ch, Ph, delta theta)
|
|
etc. etc.
|
|
0 ( end list with 2Th = 0 )
|
|
\end{verbatim}
|
|
|
|
The program will only suggest sets of indexed HKL's if all
|
|
reflections are explained. If not, the user must himself look
|
|
through the list of observed and calculated angles to find a
|
|
partial list.
|
|
|
|
|
|
\subsection{RAFIN}
|
|
This program determines orientation matrix ( ub) from two or more
|
|
sets of orientation angles for reflections, and refines
|
|
(optionally) wavelength; zeroes of 2Theta, Omega or Chi; a, b, c,
|
|
alpha, beta or gamma.
|
|
|
|
|
|
To call the program, type :--
|
|
rafin
|
|
after having set up the input file :
|
|
|
|
The input data are on rafin. dat
|
|
(teletype input can be used, but is cumbersome)
|
|
|
|
Use teco to make or correct the file.
|
|
|
|
An example of the input file ( comments in parentheses ) :--
|
|
\begin{verbatim}
|
|
0 1 (second no. 0/1 for ub not transferred/transferred to lsd)
|
|
0 (always)
|
|
0 -4 -2 28.01 13.75 81.59 42.05 (H K L 2Theta Omega Chi Phi)
|
|
4 -6 7 50.84 25.37 34.04 18.41
|
|
-2 -6 0 41.55 20.53 66.93 59.99
|
|
4 0 4 19.74 9.94 -16.92 -5.40
|
|
1 -5 -3 35.59 17.70 82.32 1.40
|
|
6 0 0 18.47 9.26 -2.32 -46.95
|
|
0 .8405 (0/1 do not/do refine lambda; and lambda)
|
|
0 0.0 1 0.0 1 0.0 (0/1 for do not/do refine, 2Theta zero,
|
|
-0/1 for do not/do refine, Om zero,
|
|
-0/1 for do not/do refine, Chi zero.
|
|
0 15.9158 0 7.1939 0 14.277 0 90 0 98.72 0 90 (ditto for a, b, c, alpha, beta and gamma)
|
|
2 0 0 (H K L list for angles to be calculated)
|
|
0 2 0
|
|
0 0 2
|
|
0 0 0 (end of list)
|
|
-1 (end of input file)
|
|
\end{verbatim}
|
|
|
|
Ensure that lsd is not running if you wish to transfer the
|
|
matrix and wavelength directly into its parameter section,
|
|
otherwise it may not be successful.
|
|
rafin will never modify the zeroes for you. This is for you to do
|
|
by adding them to the values in zer of par. Remember that for a
|
|
well aligned diffractometer, they will never change by very much.
|
|
|
|
Note: the first two reflections should be far away enough in
|
|
reciprocal space to define a plane. They must be at least 45 deg
|
|
apart in Phi and only one may have Chi greater than 45 deg.
|
|
|
|
Note also that higher angle (Theta) reflections usually give a
|
|
better fit.
|
|
|
|
You cannot, obviously, refine lambda and your cell at the same
|
|
time.
|
|
|
|
|
|
\subsubsection{Acknowledgements}
|
|
|
|
The index program was written by M.S.Lehmann,
|
|
and J.M.Savariault.
|
|
|
|
The rafin program was implemented at the ill by A.Filhol and
|
|
M.Thomas.
|
|
It was implemented on the pdp 11 system by A.Barthelemy.
|
|
|
|
|
|
|
|
\subsection{HKLGEN}
|
|
|
|
THIS PROGRAM IS USED TO GENERATE A LIST OF HKL's which can be used
|
|
for input to the measurement routines of lsd.
|
|
Indices can be generated internally in lsd, but it is generally
|
|
considered easier to create a list, and measure from this.
|
|
|
|
hklgen will generate HKL's according to min and max specified
|
|
indices, and will write them into output file(s) if they are inside
|
|
the Theta limits.
|
|
|
|
If chi and phi limits are specified, the program will also look
|
|
to see if the hkl is measurable inside these machine limits.
|
|
|
|
If not, it will see if the Friedel Pair is inside limits
|
|
|
|
If this is also outside limits, it will see if the reflection can
|
|
be measured for hkl psi=180
|
|
|
|
- note this option means chi = 90 -> 180 i.e. up-side-down.
|
|
|
|
If measurement is not possible for any of these conditions, the
|
|
hkl is declared blind.
|
|
|
|
Comments like fr.pr hichi blind indicate these on tty output.
|
|
|
|
To run the program do :--
|
|
|
|
hklgen
|
|
Input to the program is either from the terminal or from a file
|
|
hklgen.dat, already created by the user.
|
|
|
|
\subsubsection{Input from Terminal}
|
|
The first question asked under this option is whether a file
|
|
hklgen.dat should be created.
|
|
If subsequent runs are envisaged, this might be a good idea. In
|
|
this case teco can be used to make small changes to the input and
|
|
the program can be quickly re-run.
|
|
hklgen then asks for the following parameters :--
|
|
\begin{enumerate}
|
|
\item Title. Up to 80 characters to be displayed at the top of the
|
|
output.
|
|
\item Wavelength and the 9 'rules limiting possible reflections' -
|
|
see appendix C -- If you give wavelength = 0, the wavelength,
|
|
extinction rules, and orientation matrix will be taken from
|
|
lsd's parameter files.
|
|
chi and phi software limits are also taken but an
|
|
opportunity is given to over-write them.
|
|
-- If the wavelength is given explictly, followed by up to 9
|
|
numbers for the extinction rules, the orientation matrix must
|
|
then be given line by line.
|
|
\item Theta limits. ( Note not 2-Theta limits ).
|
|
chi and phi limits ( if required ) must also be given in
|
|
this line.
|
|
-- If zeroes are given, no limits will be included in the
|
|
calculations.
|
|
-- If nothing is given, LSD's limits will be used if data was
|
|
taken from the parameter files, or it will default to zeroes
|
|
if the data above was given by the user.
|
|
\item Three numbers indicating the relative speed of variation of
|
|
h, k and l.
|
|
First number is the slowest changing index, third number is
|
|
the fastest changing index.
|
|
1/2/3 is used to represent h/k/l.
|
|
e.g. 3 2 1 means L changes slowest, then K, with H changing
|
|
fastest.
|
|
\item Minimum and maximum indices in hkl are now requested.
|
|
You must give hmin hmax kmin kmax lmin lmax.
|
|
Note however that before starting the calculations, hklgen
|
|
calculates itself what is the maximum value for each index for
|
|
the specified Theta range and if this is inside these values,
|
|
they will be modified.
|
|
Therfore, if, for example 0 999 0 999 -999 999 is given,
|
|
hklgen will calculate the maximum values and give HKL's for
|
|
positive H, positive K, positive and negative L.
|
|
\item Four numbers concerning various outputs from the program.
|
|
a) The first npunch concerns the hkl output file.
|
|
0 = no file for output
|
|
1 = file for output containing hkl only in 3I4 format.
|
|
2 = file for d15-ren ( not for d8-d9 )
|
|
3 = file for output containing hkl and setting angles.
|
|
b) The second ipara concerns machine geometry.
|
|
0 = Bissecting geometry - (normal for d8-d9 ).
|
|
1 = Normal beam geometry - ( rarely used on d8-d9 )
|
|
3 = d15 lifting counter mode ( used with npunch = 2 )
|
|
c) The third number nbites concerns hkl output.
|
|
1 = write hkl for each case in four separate files.
|
|
0 = write all HKL's in one single file FOR00x. dat
|
|
( x specified below ).
|
|
d) The fourth number nlist concerns terminal output.
|
|
0 = write each hkl with angles and comment on terminal.
|
|
( can take time and consume paper ).
|
|
1 = suppress most of the output on tty.
|
|
\item If in previous line FOR00x. dat was specified for hkl output,
|
|
X must be given.
|
|
This is the last line in the input but is not always
|
|
necessary.
|
|
\end{enumerate}
|
|
The program then generates as specified, creating file(s) if
|
|
required. It gives a resume at the end and exits.
|
|
|
|
\subsubsection{Input from file hklgen.dat}
|
|
|
|
Input is given in exactly the same order as above, so for a more
|
|
detailed description of each parameter see previous section.
|
|
|
|
Two possible examples are given below.
|
|
\begin{verbatim}
|
|
KNUDDERKRYSTAL LAVET AF AARKVARD, 120K (Text, 80 characters)
|
|
0.8405 0 0 0 0 0 0 0 0 0 (Wavelength and the 9 Extinction rules. )
|
|
0.043361 -.04190 .5399 ( ub given in three separate lines
|
|
-.046409 -.032053 .03721 - as wavelength is given explicitly
|
|
-.00256 -.12861 -.02687
|
|
0 36 -20 95 ( Theta limits and Chi limits - note - no limits on Phi. )
|
|
2 1 3 ( relative speeds of hkl. - K slowest - L fastest. )
|
|
-99 -1 0 5 -99 99 ( Hmin,Hmax,Kmin, etc. - note all L's with all neg
|
|
1 0 0 1 ( a) Output file of hkl.
|
|
b) Bisecting geom - usual.
|
|
c) All HKL's in for00x.dat.
|
|
d) Suppress most tty output. )
|
|
3 ( hkl file on for003.dat )
|
|
\end{verbatim}
|
|
|
|
hklgen is a program which has evolved in the hands of :
|
|
A.Filhol, S.Mason. A.Barthelemy and J.Allibon.
|
|
|
|
\subsection{Encoding of Extinction Rules}
|
|
\begin{verbatim}
|
|
HKL
|
|
0 : NO CONDITIONS
|
|
1 : H + K + L = 2n
|
|
2 : H, K, L all even or all odd
|
|
3 : -H + K + L = 3n
|
|
4 : H = K + L = 3n
|
|
5 : H + K = 2n
|
|
6 : K + L = 2n
|
|
7 : H + L = 2n
|
|
8 : H + K + L = 6n
|
|
9 : H, K, L all even
|
|
10 : H, K, L all odd
|
|
11 : If H - K = 3n, then L = 6n
|
|
H K 0
|
|
0 : No conditions
|
|
1 : H = 2n
|
|
2 : K = 2n
|
|
3 : H + K = 2n
|
|
4 : H + K = 4n
|
|
0 K L
|
|
0 : No conditions
|
|
1 : K = 2n
|
|
2 : K + L = 2n
|
|
3 : K + L = 3n
|
|
4 : K + L = 4n
|
|
5 : L = 2n
|
|
H 0 L
|
|
0 : No conditions
|
|
1 : L = 2n
|
|
2 : H = 2n
|
|
3 : L + H = 2n
|
|
4 : L + H = 4n
|
|
H H L
|
|
0 : No conditions
|
|
1 : L = 2n
|
|
2 : H = 2n
|
|
3 : 2H + L = 4n
|
|
|
|
\end{verbatim}
|
|
% html: Beginning of file: `mesure.htm'
|
|
|
|
\section{Reflection List Processor}
|
|
|
|
\label{f19}
|
|
|
|
This section describes the means for doing a standard single counter four
|
|
circle diffractometer measurement with SICS. A prerequisite for that is a
|
|
file with a list of reflections to measure. This is a simple file with
|
|
three floating point values per line giving the HKL of the reflection to
|
|
measure. Do not forget to put standard reflections into that file any now
|
|
and then. Another prerequisite is, that the UB-matrix had been determined
|
|
beforehand and that SICS has the updated values. Also check the value of
|
|
lambda in the hkl-object.
|
|
|
|
The measurement procedure is rather simple: If a reflection is accessible
|
|
the diffractometer is positioned on that reflection. Then a scan is done for
|
|
the reflection and data written to file. The scans all run with a fixed scan
|
|
widths, counter preset and countmode. There is a choice of omega scan or
|
|
omega two theta scan. It is known that there are more sophisticated
|
|
measurement schemes for four circle diffraction, but as TRICS is only
|
|
temporarily operated with a single counter not much optimisation seemed
|
|
necessary.
|
|
|
|
Three files will be written starting from a root such as tricsnumberyear.
|
|
For instance trics05601998 means file number 560 in 1998. The file ending in
|
|
.log will contain the console log. This is extremely verbose. Another file
|
|
ending with .col will contain the reflection, diffractometer settings and
|
|
the measured profile. The third file, ending with .rfl will contain for each
|
|
refelction, the HKL, the diffractometer settings and the intensity and sigma
|
|
intensity as calculated by the SICS internal integration routine. It does
|
|
a Grant Gabe integration (see J.Appl. Cryst (1978), 11, 114-120).
|
|
|
|
For the purpose of the command description it is assumed, that this facility
|
|
is accessible as object mess within SICS.
|
|
Interaction with this object happens through the following commands:
|
|
\begin{description}
|
|
\item[mess start] Creates a new set of files and writes some header info.
|
|
\item[mess measure filename iSkip] Starts a measurement. Reads reflections from the file filename. iSkip is
|
|
an optional parameter which allows to skip iSkip lines in the file. This
|
|
is for recovery in cases of accidental or purposeful interruption
|
|
of the measurement.
|
|
\item[mess genlist filename iSkip] Mesures reflection from filename. The file is expected to have been
|
|
created by hklgen and to include all the angle settings. The optional
|
|
parameter iSkip determines the number of lines to skip in the file. This
|
|
feature allows to continue measurement on not fully processed files.
|
|
\item[mess reopen filename] Reopens an already existing file set for appending. Only the file root
|
|
without directory info or endings needs to be given.
|
|
\item[mess close] Closes the current data file set.
|
|
\item[mess file] Prints the current data file name.
|
|
\end{description}
|
|
Then there are a few parameter commands. They follow the general scheme:
|
|
\begin{description}
|
|
\item[mess parameter] Prints the current value of the parameter
|
|
\item[mess parameter value] Sets the parameter to the new value.
|
|
\end{description}
|
|
This object knows about the following parameters:
|
|
\begin{description}
|
|
\item[countmode] The counting mode to use. Possible values are timer or monitor.
|
|
\item[preset] The preset to use for counting
|
|
\item[mode] The measurement mode. Posssible values are omega for omega scans and
|
|
omega2theta for omega two theta scans.
|
|
\item[np] number of points to collect for each profile.
|
|
\item[step] The step width in omega to use for scanning.
|
|
\end{description}
|
|
|
|
This object supports some file management functionality. It caters
|
|
for the problem that experiments may need to be continued. Thus reopening
|
|
files and continuation of reflection processing at a point way down the
|
|
reflection file is supported. Consequently the start of a new experiment
|
|
requires the following steps:
|
|
\begin{itemize}
|
|
\item Create a new set of files with {\bf mess start}.
|
|
\item Configure the scans with the parameter commands.
|
|
\item Start processing a reflection file with either the {\bf mess genlist}
|
|
or {\bf mess measure} commands.
|
|
\end{itemize}
|
|
If you need to continue reflection file processing after an abort or after
|
|
solving a problem the following steps are required:
|
|
\begin{itemize}
|
|
\item Determine the file number you were working at and the line number in the
|
|
reflection file where you wish to continue processing.
|
|
\item Set the file root with the {\bf mess reopen} command.
|
|
\item Configure the scan parameters again.
|
|
\item Restart the measurement with either {\bf mess genlist} or {\bf mess
|
|
measure} but specify the iSkip parameter according to the position in
|
|
the reflection file where processing should continue.
|
|
\end{itemize}
|
|
|
|
% html: End of file: `mesure.htm'
|
|
% html: Beginning of file: `tricspsd.htm'
|
|
|
|
\chapter{TRICS with Position Sensitive Detectors}
|
|
|
|
\label{f3}
|
|
|
|
As there are no PSD's available for TRICS, not much can be found here.
|
|
In terms of software the following pieces are already available:
|
|
\begin{itemize}
|
|
\item Instructions for dealing wih
|
|
histogram memory (cf.\ Section~\ref{f20}).
|
|
\item NeXus (cf.\ Section~\ref{f21}) data handling for TRICS.
|
|
\end{itemize}
|
|
|
|
% html: End of file: `tricspsd.htm'
|
|
% html: Beginning of file: `histogram.htm'
|
|
|
|
\section{Histogram memory}
|
|
|
|
\label{f20}
|
|
|
|
|
|
Histogram memories are used in order to control large area sensitive
|
|
detectors or single detectors with time binning information.
|
|
Basically each detector maps to a defined memory location. The
|
|
histogram memory wizard takes care of putting counts detected in the
|
|
detector into the proper bin in memory. Some instruments resolve energy
|
|
(neutron flight time) as
|
|
well, than there is for each detector a row of memory locations mapping to
|
|
the time bins. As usual in SICS the syntax is the name of the histogram
|
|
memory followed by qualifiers and parameters. As a placeholder for the
|
|
histogram memories name in your system, HM will be used in the following
|
|
text.
|
|
|
|
A word or two has to be lost about the SICS handling of preset values for
|
|
histogram memories.
|
|
Two modes of operation have to be distinguished: counting until a timer has passed,
|
|
for example: count for 20 seconds. This mode is called timer mode. In the other
|
|
mode, counting is continued until a control monitor has reached a certain
|
|
preset value. This mode is called Monitor mode. The preset values in Monitor
|
|
mode are usually very large. Therefore the counter has an exponent data variable.
|
|
Values given as preset are effectively 10 to the power of this exponent. For
|
|
instance if the preset is 25 and the exponent is 6, then counting will be
|
|
continued until the monitor has reached 25 million. Note, that this scheme with
|
|
the exponent is only in operation in Monitor mode.
|
|
|
|
\subsection{ Configuration}
|
|
|
|
|
|
|
|
A HM has a plethora of configuration options coming with it which define
|
|
memory layout, modes of operation, handling of bin overflow and the like.
|
|
Additionally there are HM model specific parameters which are needed
|
|
internally in
|
|
order to communicate with the HM. In
|
|
most cases the HM will already have been configured at SICS server startup
|
|
time. However, there are occasion where these configuartion option need to
|
|
enquired or modified at run time. The command to enquire the current value
|
|
of a configuration option is: {\bf HM configure option}, the command to set it is:
|
|
{\bf HM configure option newvalue}. A list of common configuration options and their
|
|
meaning is given below:
|
|
\begin{description}
|
|
\item[ HistMode] HistMode describes the modes of operation of the histogram memory.
|
|
Possible values are:
|
|
\begin{itemize}
|
|
\item Transparent, Counter data will be written as is to memory. For debugging
|
|
purposes only.
|
|
\item Normal, neutrons detected at a given detector will be added to the
|
|
apropriate memory bin.
|
|
\item TOF, time of flight mode, neutrons found in a given detector will be
|
|
put added to a memory location determined by the detector and the time
|
|
stamp.
|
|
\item Stroboscopic mode. This mode serves to analyse changes in a sample due
|
|
to an varying external force, such as a magnetic field, mechanical stress
|
|
or the like. Neutrons will be stored in memory according to detector
|
|
position and phase of the external force.
|
|
\end{itemize}
|
|
\item[ OverFlowMode] This parameter determines how bin overflow is handled. This happend
|
|
when more neutrons get detected for a particular memory location then are
|
|
allowed for the number type of the histogram memory bin. Possible values
|
|
are:
|
|
\begin{itemize}
|
|
\item Ignore. Overflow will be ignored, the memory location will wrap around
|
|
and start at 0 again.
|
|
\item Ceil. The memory location will be kept at the highest posssible value
|
|
for its number type.
|
|
\item Count. As Ceil, but a list of overflowed bins will be maintained.
|
|
\end{itemize}
|
|
\item[ Rank] Rank defines the number of histograms in memory.
|
|
\item[ Length ] gives the length of an individual histogram.
|
|
\item[ BinWidth] determines the size of a single bin in histogram memory in bytes.
|
|
\item[dim0, dim1, dim2, ... dimn] define the logical dimensions of the histogram. Must be set if the
|
|
the sum command (see below) is to be used. This is a clutch necessary to
|
|
cope with the different notions of dimensions in the SINQ histogram memory
|
|
and physics.
|
|
\end{description}
|
|
For time of flight mode the time binnings can be retrieved and modified with
|
|
the following commands. Note that these commands do not follow the configure
|
|
syntax given above. Please note, that the usage of the commands for
|
|
modifying time bins is restricted to instrument managers.
|
|
\begin{description}
|
|
\item[HM timebin] Prints the currently active time binning array.
|
|
\item[HM genbin start step n] Generates a new equally spaced time binning array. Number n time bins
|
|
will be generated starting from start with a stepwidth of step.
|
|
\item[HM setbin inum value] Sometimes unequally spaced time binnings are needed. These can be
|
|
configured with this command. The time bin iNum is set to the value value.
|
|
\item[HM clearbin] Deletes the currently active time binning information.
|
|
\end{description}
|
|
|
|
\subsection{Histogram Memory Commands}
|
|
|
|
|
|
|
|
Besides the configuration commands the HM understands the following
|
|
commands:
|
|
\begin{description}
|
|
\item[HM preset] with a new value sets the preset time or monitor for counting. Without a
|
|
value prints the current value.
|
|
\item[HM exponent] with a new value sets the exponent to use for the preset time
|
|
in Monitor mode. Without a
|
|
value prints the current value.
|
|
\item[CountMode ] with a new values sets the count mode. Possible values are Timer for a
|
|
fixed counting time and Monitor for a fixed monitor count which has to be
|
|
reached before counting finishes. Without a value print the currently active
|
|
value.
|
|
\item[HM init ] after giving configuration command sthis needs to be called in order to
|
|
transfer the configuration from the host computer to the actual HM.
|
|
\item[HM count] starts counting using the currently active values for CountMode and
|
|
preset. This command does not block, i.e. in order to inhibit further
|
|
commands from the console, you have to give Success afterwards.
|
|
\item[HM InitVal val] initialises the whole histogram memory to the value val. Ususally 0 in
|
|
order to clear the HM.
|
|
\item[ HM get i iStart iEnd] retrieves the histogram number i. A value of -1 for i denotes retrieval
|
|
of the whole HM. iStart and iEnd are optional amd
|
|
allow to retrieve a subset of a histogram between iStart and iEnd.
|
|
\item[HM sum d1min d1max d2min d2max .... dnmin dnmax] calculates the sum of an area on the detector. For each dimension a
|
|
minimum and maximum boundary for summing must be given.
|
|
\end{description}
|
|
|
|
% html: End of file: `histogram.htm'
|
|
% html: Beginning of file: `nextrics.htm'
|
|
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\section{TRICS NeXus File Writing Object}
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\label{f21}
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TRICS writes its data files in the upcoming NeXus data format standard for
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neutron scattering and X-ray diffraction. The user may interact with this
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object through the following commands:
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\begin{description}
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\item[nexus start] Starts a new NeXus file.
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\item[nexus reopen filename] Reopens a NeXus file which has already been written to.
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\item[nexus dumpframe] Writes a frame of data at the current settings to the NeXus file.
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\item[nexus file] Prints the filename of the data file currently in use.
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\end{description}
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% html: End of file: `nextrics.htm'
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\end{document}
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