Error with GPIB connecting a Keithley sourcemeter

[akhil011235]

Hi 

I have a vi for making N measurements, put them in an array, calculate mean value and SD. The measurements are obtained from a Keithley 2401 Sourcemeter which is connected using a GPIB-USB-HS. This vi was working previously. 

When I run the vi, it shows an error message with two possible reasons (1) LabVIEW memory is full and (2) NI-488: No listeners on the GPIB.

When the highlight execution is used, the error is occuring at the 'Send' (GPIB 488.2 Palette).

The vi is attached. Could someone please have a look. I am a beginner in LabVIEW and any help is very much appreciated.

Akhil

[Norbert_B]

Besides that the LV VI does not contain well designed LV code (ughs, sequence structures all over the place!), i would guess that the address of the device is not 3.

Please use NI MAX to verify the address/functionality of the device. Also you might want to check if the cable is still correctly attached and the device is turned on.

Norbert

[crossrulz]

You should not need the secondary GPIB address.  If your sourcemeter is set to 3, just use the address of 3.

[akhil011235]

Thank you both for the quick reply. This vi was written by the person who was using the equipment previously and she has already left.

I believe the address of of the GPIB is 24 as MAX shows GPIB0::24::INSTR.

When I changed the primary address to 24, error messages are no longer appearing in LabVIEW, but the Keithley shows an error code -113. This code means a syntax error, I believe. 

About the secondary address, it changes between 7, 8 and 9 from the the stacked sequences in the first flat sequence. I am not entirely sure why. Could this be due to the fact that this vi is a sub vi of another vi? (This another vi also has the same errors and thats why thought about looking at this one first)

Akhil

PS. Cable is properly connected and the device is powered on.

[Norbert_B]

Akhil,

you have to find out the information about that device error on your own. However, my feeling/experience tells me that you also swapped computer to a way faster one. It is very possible that you are dealing with a timing issue. If you enable highlight execution, does the error still occur?

Norbert

[akhil011235]

Thanks Norbert. Yes, even with the highlight on, keithley shows the error. Do you know if I really need the secondary address/ MakeAddr palette? 

[Norbert_B]

Well, i wouldn't use the low level GPIB commands at all. I would simply go for NI VISA functions.....

No, i don't know if secondary address could be involved in creating the error. What does that error for that specific instrument mean?

Norbert

[akhil011235]

According to Keithley, "the -113 error is a syntax error that comes from when you either add an incorrect space such as :SYST :ERR? (incorrect) vs :SYST:ERR?(correct) or if you're missing a necessary space such as :SENS:VOLT:DC:RANGl00 (incorrect) vs. :SENS:VOLT:DC:RANG 100 (correct). So somewhere in your code there is a command that is most likely either missing a space or has an unnecessary space in it".

Any idea?

[Norbert_B]

Your string fields (e.g. Gain G) do not have any values by default. Make sure to enter values before running the VI.

Also identify which "Send" node is creating the error and verify the string value you pass to it.

Norbert