Sample Environment Devices

From here you can jump to:

A discussion of SICS environment control concepts.
A section about environment control error handling.
Commands for monitoring and installing environment control devices.
Commands understood by ALL environment control devices.
LakeShore Model 340 temperature controllers.
Oxford Instruments ITC-4 or ITC-503 temperature controllers.
Dilution Cryostat.
Haake waterbath thermostat.
The CryoFurnace with its Neocera LTC-11 temperature controller.
Eurotherm Temperature Controller.
Bruker Magnet Controller.
The PSI-EL755 Magnet Controller.

SICS Concepts for Sample Environment Devices

SICS can support any type of sample environment control device if there is a driver for it. This includes temperature controllers, magnetic field controllers etc. The SICS server is meant to be left running continously. Therefore there exists a facility for dynamically configuring and deconfiguring environment devices into the system. This is done via the EVFactory command. It is expected that instrument scientists will provide command procedures or specialised Rünbuffers for configuring environment devices and setting reasonable default parameters.

In the SICS model a sample environment device has in principle two modes of operation. The first is the drive mode. The device is monitored in this mode when a new value for it has been requested. The second mode is the monitor mode. This mode is entered when the device has reached its target value. After that, the device must be continously monitored throughout any measurement. This is done through the environment monitor or emon. The emon understands a few commands of its own.

Within SICS all sample environement devices share some common behaviour concerning parameters and abilities. Thus any given environment device accepts all of a set of general commands plus some additional commands special to the device.

In the next section the EVFactory, emon and the general commands understood by any sample environment device will be discussed. This reading is mandatory for understanding SICS environment device handling. Then there will be another section discussing the special devices known to the system.

SampleEnvironment Error Handling

A sample environment device may fail to stay at its preset value during a measurement. This condition will usually be detected by the emon. The question is how to deal with this problem. The requirements for this kind of error handling are quite different. The SICS model therefore implements several strategies for handling sample environment device failure handling. The strategy to use is selected via a variable which can be set by the user for any sample environment device separately. Additional error handling strategies can be added with a modest amount of programming. The error handling strategies currently implemented are:

Lazy: Just print a warning and continue.
Pause: Pauses the measurement until the problem has been resolved.
Interrupt: Issues a SICS interrupt to the system.
Safe: Tries to run the environment device to a value considered safe by the user.

General Sample Environment Commands

EVFactory

EVFactory is responsible for configuring and deconfiguring sample environment devices into SICS. The syntax is simple:

EVFactory new name type par par ...: Creates a new sample environment device. It will be known to SICS by the name specified as second parameter. The type parameter decides which driver to use for this device. The type will be followed by additional parameters which will be evaluated by the driver requested.
EVFactory del name: Deletes the environment device name from the system.

emon

The environment monitor emon takes for the monitoring of an environment device during measurements. It also initiates error handling when appropriate. The emon understands a couple of commands.

emon list: This command lists all environment devices currently registered in the system.
emon register name: This is a specialist command which registers the environment device name with the environment monitor. Usually this will automatically be taken care of by EVFactory.
emon unregister name: This is a specialist command which unregisters the environment device name with the environment monitor. Usually this will automatically be taken care of by EVFactory Following this call the device will no longer be monitored and out of tolerance errors on that device no longer be handled.

General Commands UnderStood by All Sample Environment Devices

Once the evfactory has been run successfully the controller is installed as an object in SICS. It is accessible as an object then under the name specified in the evfactory command. All environemnt object understand the common commands given below. Please note that each command discussed below MUST be prepended with the name of the environment device as configured in EVFactory!

The general commands understood by any environment controller can be subdivided further into parameter commands and real commands. The parameter commands just print the name of the parameter if given without an extra parameter or set if a parameter is specified. For example:

Temperature Tolerance

prints the value of the variable Tolerance for the environment controller Temperature. This is in the same units as the controller operates, i. e. for a temperature controller Kelvin.

Temperature Tolerance 2.0

sets the parameter Tolerance for Temperature to 2.0. Parameters known to ANY envrironment controller are:

Tolerance

Is the deviation from the preset value which can be tolerated before an error is issued.

Access

Determines who may change parameters for this controller. Possible values are:

0 only internal
1 only Managers
2 Managers and Users.
3 Everybody, including Spy.

LowerLimit

The lower limit for the controller.

UpperLimit

The upper limit for the controller.

ErrHandler.

The error handler to use for this controller. Possible values:

0 is Lazy.
1 for Pause.
2 for Interrupt
3 for Safe.

For an explanantion of these values see the section about error handling above.

Interrupt

The interrupt to issue when an error is detected and Interrupt error handling is set. Valid values are:

0 for Continue.
1 for abort operation.
2 for abort scan.
3 for abort batch processing.
4 halt system.
5 exit server.

SafeValue

The value to drive the controller to when an error has been detected and Safe error handling is set.

Additionally the following commands are understood:

send par par ...: Sends everything after send directly to the controller and return its response. This is a general purpose command for manipulating 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 calibration tables etc.
list: lists all the parameters for this controller.
no command, only name.: When only the name of the device is typed it will return its current value.
name val: will drive the device to the new value val. Please note that the same can be achieved by using the drive command. and log frequency (both below)

Logging

The values of any sample environement device can be logged. There are two features:

Logging to a file wih a configurable time intervall between log file entries.
Sums are kept internally which allow the calculation of the mean value and the standard deviation at all times.

The last system is automatically switched on after the first drive or run command on the environment device completed. This system is run through the following commands.

name log clear: Resets all sums for the calculation of the mean value and the standard deviation.
name log getmean: Calculates the mean value and the standard deviation for all logged values and prints them.
name log frequency val: With a parameter sets, without a parameter requests the logging intervall for the log file. This parameter specifies the time intervall in seconds between log records. The default is 300 seconds.
name log file filename: Starts logging of value data to the file filename. Logging will happen any 5 minutes initially. The logging frequency can be changed with the name log frequency command. Each entry in the file is of the form date time value. The name of the file must be specified relative to the SICS server.
name log flush: DigitalUnix buffers output heavily. With this command an update of the file can be enforced.
name log status: Queries if logging to file is currently happening or not.
name log close: Stops logging data to the file.

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!

LakeShore Model 340 Temperature Controller

This is the temperature controller for cryogenic applications and should replace at least the Oxford & Neocera controllers at SINQ.

The control is handled by a seperate server process TECS (TEmperature Control Server) and is initialized by default. If there is already an other device selected, it must be deleted and TECS must be reinstalled:

EVFactory del temperature
EVFactory new temperature tecs

The sample environment device is selected automatically by a coding in the plug of the sensor/heater cable(s). If this does not work (plugs without coding or temporarely use of a wrong cable) you may select the device with

temperature device device

You may want to verify the selected device with

temperature device

The actually known devices (April 2000) are:

orange cryostats: ill1 (50mm), ill2 (70mm), ill3 (cryofurnace), ill4 (FOCUS), ill5 (100 mm)
closed cycles: cti1, cti2, cti3, cti4, cti5 (maxi), cti6 (FOCUS), apd (TriCS), ccr4k (4K)
other: hef4c (He-flow cryostat 4circle), sup4t (4 T supraconducting magnet)

ITC-4 and ITC-503 Temperature Controllers

These temperature controller were fairly popular at SINQ. They are manufactured by Oxford Instruments. At the back of this controller 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.

ITC-4 Initialisation

An ITC-4 can be configured into the system by:

EVFactory new Temp ITC4 computer port channel

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:

EVFactory new Temp ITC4 lnsp22.psi.ch 4000 7

connects Temp to the Macintosh named lnsp22, serial port 6 (7 above is no typo!), listening at port 4000.

ITC-4 Additional Parameters

The ITC-4 has a few more parameter commands:

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 appear.
sensor: Sets the sensor number to be used for reading temperature.
control: Sets the control sensor for the ITC-4. This sensor will be used internally for regulating the ITC-4.
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. It is usually 10 for a sensor with one value behind the comma or 100 for a sensor with two values after the comma.
multiplicator: The same meaning as the divisor above, but for the control sensor.

Installing an ITC4 step by step

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.
Install the ITC4 into SICS with the command:
evfactory new name Macintoshname 4000 7
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:
evfactory del name
will help. Macintoshname is the name of the instrument Macintosh PC.
Configure the upper and lowerlimits for your controller appropriatetly.
Figure out which sensor you are going to use for reading temperatures. Configure the sensor and the divisor parameter accordingly.
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.
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.
Select one of the numerous error handling strategies the control software is able to perform. Configure the device accordingly.
Test your setting by trying to read the current temperature.
If this goes well try to drive to a temperature not to far from the current one.

ITC-4 Trouble Shooting

If the ITC-4 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 message may also come up as a failure to connect to the ITC-4 during startup.

If error messages containing the string ?TMO keep appearing up followed by signs that the command has not been understood, then increase the timeout. The standard timeout of 10 microseconds can be to short sometimes.

You keep on reading 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 trying to drive the ITC4. These are usually the result of a badly set multiplicator parameter for the control sensor.

The ITC4 never stops driving. There are at least four possible causes for this problem:

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.
The software is reading back incorrect temperature values 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 the parameters accordingly.
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.
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.

Haake Waterbath Thermostat

This is sort of a bucket 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:

inihaakearray name-of-array macintosh-computer name port channel
evfactory new temperature tcl name-of-array

An example for the SANS:

inihaakearray eimer lnsp25.psi.ch 4000 1
evfactory new temperature tcl eimer

Following this, the thermostat can be controlled with the other environment control commands.

The Haake Thermostat understands a single special subcommand: 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:

temperature sensor val

val can be either intern or extern.

Dilution Cryostat

This is a large ancient device for reaching very low temperatures. This cryostat can be configured into SICS with the command:

EVFactory new Temp dillu computer port channel table.file

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:

evfactory new temperature dillu lnsp19.psi.ch 4000 1 dilu.tem

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.

Bruker Magnet Controller B-EC-1

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 field mode the current for the magnet is controlled via an external hall sensor at the magnet. In current mode, the output current of the device is controlled. This magnet can be configured into SICS with a command syntax like this:

evfactory new name bruker Mac-PC Mac-port Mac-channel

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):

evfactory new magnet bruker lnsp25.psi.ch 4000 9

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:

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.
magnet polarity val: sets a new polarity for the controller. Possible values for val are minus or plus. The meaning is self explaining.
magnet mode: Prints the current control mode of the controller. Possible answers are field for control via hall sensor or current for current control.
magnet mode val: sets a new control mode for the controller. Possible values for val are field or current. The meaning is explained above.
magnet field: reads the magnets hall sensor independent of the control mode.
magnet current: reads the magnets output current independent of the control mode.

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.

The CryoFurnace.

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:

evfactory new name ltc11 Mac-PC Mac-port Mac-channel

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):

evfactory new temperature ltc11 lnsp18.psi.ch 4000 6

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:

temperature sensor: queries the current sensor used for temperature readout.
temperature sensor val: selects the sensor val for temperature readout.
temperature controlanalog: queries the sensor used for controlling the analog channel.
temperature controlanalog val: selects the sensor val for controlling the analog channel.
temperature controlheat: queries the sensor used for controlling the heater channel.
temperature controlheat val: selects the sensor val for controlling the heater channel.
temperature mode: queries if the LTC-11 is in analog or heater control mode.

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.

The Eurotherm Temperature Controller

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.

evfactory new name euro Mac-PC Mac-port Mac-channel

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. 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:

evfactory new temperature euro lnsp25.psi.ch 4000 13

There are two further gotchas with this thing:

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.
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.

The PSI-EL755 Magnet Controller

This is magnet controller developed by the electronics group at PSI. It consists of a controller which interfaces to a couple of power supplies. The magnets are then connected to the power supplies. The magnetic field is not controlled directly but just the power output of the power supply. Also the actual output of the power supply is NOT read back but just the set value after ramping. This is a serious limitation because the computer cannot recognize a faulty power supply or magnet. The EL755 is connected to SICS with the command:

evfactory new name el755 Mac-PC Mac-port Mac-channel index

with Mac-PC, Mac-port and Mac-channel being the usual data items for describing the location of the EL755-controller at the Macintosh serial port server. index is special and is the number of the power supply to which the magnet is connected. An example:

evfactory new maggi el755 lnsa09.psi.ch 4000 5 3

connects to power supply 3 at the EL755-controller connected to lnsa09 at channel 5. The magnet is then available in the system as maggi. No special commands are supported for the EL755.