Problem with scanning Keithley 2700

[Ranj]

Hi Nathan

Thanks for your last message....I have been trying all sorts of things i.e changing hardware swapped with another 2700....also changed multiplexer cards, GPIB cards....its definitley not the hardware...

Using sample count below 100 the program crashes.....

However the error message changed when i swapped machine...the error i am not getting is:

VISA timeout expired before operation completed

The error occurred in VISA Write in Read Multiple Direct.vi (sub vi in Finite Multi Read Example.vi)

To correct this i placed a time delay before and after VISA Write but this did not work.  Do you have any suggestions.....i am going crazy with this if i dont get this sorted i may have to resort to using TESTPOINT!!!!!

Thanks for your help...

Ranjit

[RayFarmer]

Hi,

Adding some delays in your program didn't work because you would have to increase the Timeout delay, which is usually 10sec.

This is the time VISA/GPIB allows the instrument to respond before it gives up viRead() and reports an error. You can change this default value via the property node, or there may even be a VI function in the palette.

Regards

Ray Farmer

[NathanT]

Hello Ranj,
        I think that Ray brought up a good suggestion of making your VISA timeout longer.  I recommend checking your firmware version and most likely upgrading it.  Changing the instrument's firmware could change how the instrument responds to commands and the format of the response.  To get the firmware version you can either navigate through the instrument's menus OR run Revision Query VI OR just do an ID Query.  If your firmware is not current, I highly recommend upgrading it to the most current version.  I was running the example with less than 100 samples and it worked fine, so I think that there are differences between our overall systems.  Upgrading the firmware will hopefully take out one of the variables.

Cheers,

NathanT

[Ranj]

Dear Ray

Thanks for the help, a timeout delay is set between Visa Write and Read, the default delay set is 30 sec.  I have increased and reduced but i am still getting the same problem.  If you have any other suggestions they are appreciated.  I have tried everything and may now resort to test point this week.  I do not understand why the drivers are not working for my machine....very stressed out at the moment....

Thanks

Ranj

[NathanT]

Hello Ranj,
          I still think that you should upgrade the firmware.

Cheers,

NathanT

[Ranj]

Hi Nathan

I did upgrade the firmware to version B09 it was originally B02, it hasnt made any difference.  i am trying everything thats been suggested if you have any ideas why I am having problems with scanning the channels using the drivers will be appreciated.  I have not had any luck off NI they do not seem to know.  So its down to the forum.  I have no ideas why this is not working.  The instrument has been working successfully on another PC using TESTPOINT software.  So its not the hardware its definitely the software.

Any ideas are very much appreciated.

Thanks for your help Ranj

[Albert.Geven]

Hi

So, it must be the software or the settings inside the keithley that are not standard or a problem with cabling or even possible the wrong software.

I did not see which driver you actually loaded. And Just as me everybody guesses that yuo use the latest and greatest one...

Which version of the driver are you using.

Very old drivers may be allergic for local decimal point settings that are making the scanning of the returned string troublesome.

So please tell us and/or add the used vi to the message.

[Ranj]

Hi Albert

I am reinstalling all the drivers for GPIB and instrument and Labview itself....i just hope that might help...but i am seriously doudting it.  I have checked the hardware and it all works fine its definitley something to do with the software.  I really have to fix this problem by the end of the week if not i will be using Test point.  My colleague is running testpoint perfectly with the same machine and card so its definitlely a software issue.  I am running Labview Version 8.2.  with NI VISA runtime version 4.1.  I downloaded the drivers off NI the project style version and I run the example program Finite Multi Read.vi it runs but not successfully it gets stuck with scanning the channels the machine has to be turned off and turned back on again.  The single read.vi runs perfectly (reads 1 channel, 1 scan).  So there are some issues with software.  I think i might invest in an NI GPIB card....

If you have any ideas please let me know

Thanks Ranj

[Ranj]

Hi Albert

I am reinstalling all the drivers for GPIB and instrument and Labview itself....i just hope that might help...but i am seriously doudting it.  I have checked the hardware and it all works fine its definitley something to do with the software.  I really have to fix this problem by the end of the week if not i will be using Test point.  My colleague is running testpoint perfectly with the same machine and card so its definitlely a software issue.  I am running Labview Version 8.2.  with NI VISA runtime version 4.1.  I downloaded the drivers off NI the project style version and I run the example program Finite Multi Read.vi it runs but not successfully it gets stuck with scanning the channels the machine has to be turned off and turned back on again.  The single read.vi runs perfectly (reads 1 channel, 1 scan).  So there are some issues with software.  I think i might invest in an NI GPIB card....

If you have any ideas please let me know

Thanks Ranj

[NathanT]

Hello Ranj,
       Has Keithley had anything to say about the difference in behavior between LabVIEW and the other program?  I wonder if the other program is parsing the extra data from the instrument and the LabVIEW driver is just expecting data points and not the extra data that we saw in your previous post.  It might be worthwhile to try communicating with the instrument over Serial to take the other GPIB card out of the picture.  Please make sure to delete the driver in instr.lib before putting the new one there.  I have had problems before when old VIs with different names did not get overwritten when I just put a new driver in instr.lib.  Also try using the most recent version of NI-VISA and MAX.

Cheers,

Nathan