Installation Instructions for DIFRAC on a PC
--------------------------------------------
The diskette supplied contains all files necessary to run and maintain
the DIFRAC programs on a PC controlling the diffractometer. These are
1. CAD4L.EXE -- the program to load the interface (CAD4 only).
2. DIFRAC.EXE -- the program to control the instrument;
The PC should be configured so that
a. communication between the computer and the instrument is via COM1:,
b. a printer is attached to LPT1: and
c. graphics is supported with a standard VGA (640x480) card.
The file GONIOM.INI contains constants needed by program to define the
diffractometer model, the microscope viewing position, the COM port number and
baud-rate and, in the case of the CAD4, other constants which define slit
positions, voltages etc. This file is plain ASCII and commented to facilitate
editting.
1. CAD4L (CAD-4 only)
-----
This is the analogue of the routine of the same name in the original
Enraf-Nonius control system. It loads the binary interface code and some of
the instrumental constants.
There are three versions of the binary interface code.
a. interfaces with Falcon computers require the file FALCON.EXE;
b. interfaces with LS-11 computers require the file LSI_11.EXE;
c. interfaces with Falcon+ computers require the file FALCNP.EXE.
The routine CAD4L.EXE loads the appropriate file together with the interface
resident constants from the file goniom.ini.
The instrumental constants in the file GONIOM.INI should be editted so that
it contains values appropriate to the instrument in use. These values should
be obtained from the original CAD-4 control routine with the CASPAR and GCONST
commands.
Files Needed :-- CAD4L.EXE, LSI_11.EXE or FALCON.EXE or FALCNP.EXE,
GONIOM.INI.
2. DIFRAC
------
This is the instrument control routine which carries out all
crystallographic operations and controls the diffractometer via the interface
computer. It too needs the file goniom.ini in order to obtain other
instrumental constants. The routine uses the file IDATA.DA to hold all data,
and if it does not exist when the routine is started it will be created and
sensible defaults will be supplied for most parameters.
Files Needed :-- DIFRAC.EXE, GONIOM.INI, probably IDATA.DA.
Setup Procedure
---------------
1. Create a working subdirectory and copy all files from the diskettes into this
subdirectory.
2. Non-CAD-4 machines
Connect a serial line between COM1: and the instrument interface.
Edit the file goniom.ini to ensure that it contains at least the correct values
for Dfmodl, Port, Baud, Vutht, Vuome, Vuchi and Vuphi.
2. CAD-4 Only
Before disconnecting the main PDP-11 or VAX computer from the serial line to
the interface, run the E-N control routine to obtain the instrumental
constants for the particular instrument. Edit the file GONIOM.INI to
reflect these constants as well as Dfmodl, Port, Baud, Vutht, Vuome, Vuchi and
Vuphi.
Disconnect the main computer from the interface serial line and connect the
line to COM1:. The connection needs only a straight-through (null-modem)
cable (2 to 2, 3 to 3 etc).
Run CAD4L to load the interface.
It should not be necessary to perform this step every time the
diffractometer is used. It maybe necessary to turn the interface power off
and on again after a few seconds in order to get CAD4L to run properly. The
interface baud-rate is set to 9600 and the routine reports as the 46 blocks
are loaded. If the interface has been loaded correctly, the pocket
terminal should be active and displaying the string DIFRAC. Check that
the values for HV, LL etc are those from the goniom.ini file.
3. Run DIFRAC to drive the diffractometer.
See the writeup for a description of the commands.
When DIFRAC (and CAD4L) is started a header screen appears from the
shareware used to control communication with the serial port. Follow the
simple instructions and the screen will clear as the routine is run.
Files on Diskettes
------------------
1. CAD4L.EXE, LSI_11.EXE, FALCON.EXE, FALCNP.EXE, DIFRAC.EXE, GONIOM.INI.
Library files GONIO6.LIB and PCL4.LIB.
CAD4L.MAK and CAD4L.OVL to rebuild CAD4L, and DIF.MAK and DIF.OVL
to rebuild DIFRAC, if necessary with Microsoft Fortran.
2. All source files *.FOR for CAD4L and DIFRAC. The writeup in ASCII form
as DIF.ASC and in Word-Perfect 6.1 form as DIF.WPD.
This file README.DIF.
It would probably be a good idea to copy all files before using them for any
other purpose.
In Case of Difficulties
-----------------------
Only 3 problems have been encountered with these programs.
1. The cable between the PC and the interface is not a null-modem.
2. The cable is not connected to the COM1: port.
3. CAD4L seems to load correctly, but incorrect HV, LL etc values appear in
the pocket terminal.
The first 2 problems can be solved by ensuring that the correct cable is
connected to the correct port. The third problem occurred in CAD4L and
has been fixed. If difficulties of this type are experienced contact
Eric Gabe (e-mail gabe@sg1.chem.nrc.ca).
