Using VISA with JY Horiba VI's

[Rod Ross]

I am trying to troubleshoot a Lab View program that automates
spectrometer control and water bath control. The problem is, the program
freezes at widely varying intervals(mins.-day) for no apparent reason.
We need to be able to set up this program and have it run reliably for
at least three full days to complete data acquisition. We are using an
old SPEX 1403 spectrometer, and got Lab View software from JY Horiba
that is supposed to work. It doesn't do the job. When the program
freezes, we have dug down through the sub VI's to see if there were any
error messages, and we found none. The only thing we found was a motor
busy light in one of the VI's. We have tried contacting the engineers at
Horiba and National Instruments, but have not gott
en any help. It is our
belief that during program execution, somehow communication between the
spectrometer and computer breaks down. It seems as though the computer
is waiting for some input from the spectrometer that it never gets.
Everyone that I have talked to about this problem suggests using VISA
VI's to solve the problem. Is there any way to use VISA with my existing
program and make it work? The VI's from ISA(Horiba) are using the serial
compatibility VI's. Any help would be greatly appreciated.

[mikeporter]

The basic way of converting to VISA serial io is to write versions of the existing low-level serial VIs that logicallly perform the same operations, but using VISA calls. My sense though is that this change won't inherently help the situation. It sounds like a command is timing out and that timeout condition is not being trapped correctly (if at all).

A lot of old VIs--even (especially?) NIs--contained little or no error handling. In fact it was very common for them to be written with the assumption that nothing will ever go wrong so there is no error reporting at all.

Are Horba's drivers available somewhere online? If so I'll grab a copy of them and look for logical holes in them for you.

The other half of this equation though is the logical operation
of the Horba equipment. If a communication timesout how does their control software respond? Is there any sort of special recovery operation that you have to go through? For example, getting the sort of indication you are from a spectrometer makes me wonder if the instrument is getting hung-up internally. (I'm assuming here that this spectrometer is an electromechanical device like some of the fiber-optic instrumentaion I have used in the past).

Is this instrument provide a GPIB interface? If so you might want to consider that interface for talking to the box as it can at times be more reliable and faster.

This could be a mess to troubleshoot but I'll do what I can to get things cranking for you.

Mike..