problems with LabView drivers for Keithley 236

[Malchik]

It was posted in LabVIEW forum, but I was advised to move it in this forum, so here my question:

Hello, I have illegal device dependent command option (iddco error) for all examples from ke236.lib I use Labview 5.11(GPIB interface). What is strange that after modification(just added unbundle by name for output parameters), two examples for dc-mode started to work, without error. Now situation is that if I start my modified example first, another official examples also work, if I start first official example, keithley 236 returns error and my modified example does not work too. In sweep mode I have always IDDCO error.

>>Probably what is happening is that the instrument driver was built with a different version of the
GPIB driver than what you are using. When you add something to the driver, it causes it to recompile and relink to the newer functions for GPIB. Here is what I suggest: Open up the examples and press ++LabVIEW Run Arrow. This will force a recompile and link of all VIs in that VIs hierarchy. Then choose to Save All from the File menu. Now run the examples and check if they work. If they do not, can you open the lower level VIs to see whcih function is giving you the error and where? That is the next step.

>>Ok, thank you. I tried ++LabVIEW Run Arrow and Save all, but it does not help, I still have the mistake. The mistake occurs when the subVI "Send Message" runs the command "GPIB write" with parameter: "F0,000P0Z0S1W1B2,000000E+0,0,0L1,000000E-1,0XM),XM 8,X"

>>Since this is turning into much more of a GPIB programming issue, I would suggest reposting this question (with what you have learned) in the GPIB forum instead of the LabVIEW forum. Not all of the
GPIB specialists monitor the LabVIEW forum here and they would be much better at handling this programming issue.

So, it is all for now.
Please help me.

[AaronK]

Hi Malchik,
It is hard to say what could be happening here. My guess is that you have a newer version of the instrument where the command set has changed slightly. When you run your modified program it most likely gets the instrument into some state where the others can operate.

In case you did not know, a good tool for you to use is NI-SPY. It can log interactions with the hardware and might help you out on this. Take a look at the NI-SPY logs (Start the capture and then do things as you normally would). This will help you track down what exact message and data is causing the error. Then you can crossreference this with your manual to find the solution.

One other thing to check is that all of your parameters are within spec. If you request paramete
rs that are out of range, you can run into trouble. Check the error code returned by the instrument for more detail.

Hope this helps out.

Best Regards,
Aaron K.
Application Engineer
National Instruments