Keithley 2400 driver for Labview 8 not working

[Driley13]

I searched the boards and found this driver for a Keithley 2400 that should run with Labview 8.  I have Labview 8.6.

http://sine.ni.com/apps/utf8/niid_web_display.download_page?p_id_guid=25B255F3AA83660EE0440003BA7CCD...

I put the driver folder in the proper location and the vi's are appearing in the selection menu as expected.  I have my Keithley 2400 connected to a serial port on COM1.  When I simply try to run the initialization VI it doesn't work.  I know it's communicating in some form, because my Keithley goes into remote mode and the initialization driver is able to properly read what the model of the Keithley is.  When it gets to the VISA read vi it is timing out, but still outputs the correct model identification.  I don't understand why it's timing out and not working.  

Is there something else I should've installed?  The driver readme says the only additional software required is NI-VISA 3.2, however I have version 4.4, so I should be fine.  I just don't understand why it's "sort of" working.  Any help would be greatly appreciated. 

[mikeporter]

My guess is that there is a problem with the drivers. It's not likely that a VISA driver difference would cause this sort of error. You're going to have to go through the drivers and examine what's being sent and what's being read, and compare them to the programming information in the manual.

Mike...

[Driley13]

So I don't need additional software?  I know that for the IVI drivers you need the Keithley I/O layer installed, but my impression with was that with these you just need the VISA 3.2, Labview 8.  If this is true then I can focus my search for the problem to the drivers.  

[mikeporter]

Though it is certainly possible that there could be some sort of subtle difference, Visa 4.4 should work fine - perhaps better.

Mike...

[Driley13]

Alright, I'll look at the driver tomorrow carefully and probably post some screenshots.  

[Driley13]

"Many of the instrument drivers require NI-VISA to be installed. You can download the latest version of VISA. In addition to VISA, the appropriate device driver(s) (NI-488.2, NI-VXI, etc) also need to be installed along with the appropriate hardware."

Am I possibly missing a "device driver" as this statement from the Labview "Plug and Play Instrument Driver Installation Instructions" mentions?

[mikeporter]

It doesn't sound like it. You are using serial and that requires nothing beyond VISA - plus simple commands are working. The fact that the drivers can send and receive the SCPI identification command tells me that you are communicating with the instrument. (That is what causes the instrument to tell you what kind of device it is.) The thing to remember about drivers you get from vendors is that they can be very buggy. Often times they were written by someone who doesn't know LV very well, or were perhaps donated to them by one of their customers. I always view vendor-supplied drivers as simply a starting place for creating really usable ones.

Mike...

[smercurio_fc · Accepted solution]

You should verify the terminator used to indicate the end of a message from the instrument. The 2400 can use one of 4 different terminators:

<CR>

<CR+LF>

<LF>

<LF+CR>

I'm not sure which one is the default one. The driver is written assuming <LF>, though it should work if the instrument is configured to use either <LF> or <CR+LF>. If it's configured for one of the other 2 then you will get a timeout error on the read. 

[Driley13]

Problem solved.  Thank you, sir/mam!

Message Edited by Driley13 on 02-12-2009 12:10 PM

[haitem]

Hello,

could you please explain what was the problem, because I have same problem,

thank you