Simple V-i Measurements with a Keithley 2400 Sourcemeter on LabView

[Bavley33]

I believe it is the latest firmware but I'm not 100% sure because it is the schools and I'm only using it for a project. I'll give what you said a shot and hopefully I shouldn't have any more issues. One more thing, by checking the physical setup, do you mean the parameters or the cable? Thanks a lot for your help by the way, I really appreciate it!

[cstorey]

By physical setup I mean the USB-RS232 adaptor and any RS232 extension cable you are using.  Is the adaptor installed and working properly?  Does it work with other instruments?  If you have an extension cable is it a NULL modem or straight thru cable?

Glad to help, post an update if you require further assistance.

Craig

[Bavley33]

The cable I am using is from startech and I have verified that it is straight thru.

I have checked all my configuration settings (parity etc.) and these are all matching. So, if I send the identification command, I receive this error in the return data column:

Read Operation
Error

VISA: (Hex 0xBFFF0015) Timeout expired before operation completed.

but in the buffer box, I do indeed get the serial ID of the Keithley (I checked that the name and numbers are correct):

1: Write Operation (*IDN?\n)

Return Count: 6 bytes

2: Read Operation
Return Count: 80 bytes
KEITHLEY\sINSTRUMENTS\sINC.,MODEL\s2400,4387981,C34\sSep\s21\
s2016\s15:30:00/A02\s\s/V/M\r

Now, if I try to run a sample VI (attached to this post), the same thing as before happens. The Keithley will beep, display error -113 and the VI will stop (Error:-1073807339 / VISA Read in Keithley 24XX.lvlib:Error Query.vi->Keithley 24XX.lvlib:Read (Single Point).vi).

If close the Program and reopen MAX, I am unable to the VISA test panel. I have to restart LabVIEW and the Keithley. When I re-enter the test panel, some of the settings I changed the previous time are changed back to original configuration (termination method). 

Error opening resource:
ASRL4::INSTR

VISA: (Hex 0xBFFF0072) The resource is valid, but VISA cannot currently access it.

I suspect that this has something to do with either my flow control or termination method configuration. I am new so I am not sure what they do or how they should be configured. 

[Bavley33]

Not sure what I changed but everything seems fine now! I even got my first resistance measurement with NO ERRORS! Thanks again for your help, much appreciated!

[cstorey · Accepted solution]

Good to hear.  To me it looks like your termination characters were mismatched.  \n for write and \r for the return string.  Perhaps you reset those in Max and it now works with VISA.  Anyway, glad its working.

[Bavley33]

Yes, I used the reset command (from the manual) and I asked for the ID again but, this time I got it with no errors so I believe it was that. It shouldn't be too hard working with it now.