Read command generating timeout via GPIB from Fluke 8842a

[blood29]

I have one Fluke 8842a connected using GPIB to USB interface (I have a UGPlus controller-cable and not a NI version). I am trying to use Labview to read the instrument data using call library function - dlls. In specific, I am reading ultra-low resistance values from Fluke.

The problem is that the read function doesn't work if I set high-precision (smallest resistance range - 0.xxxx ohms) on Fluke and gives me a timeout. Even a single input read command doesn't work in this range. Strangely, all other ranges like 0.xxx or more higher ranges work just fine. The only problem occurs is in the lowest range/high-precision data reading.

Fluke manual portrays that it takes approx 1.24 reading/sec in high-precision ranges. Any ideas what may be wrong with this?

Thanks!

[santo_13]

Might have something to do with character ending configuration for GPIB or some bug in the SCPI command. Were you able to confirm if the instrument received the command and started an acquisition when you send a command from PC?

Sharing the VI snippet and the programmer's manual would highly help us to guide you.

[Minions]

My suggestion would be to bump up the connection timeout for this instrument.  Try to set it to 30 seconds first.  If that works, try it down around 5 seconds.

[cstorey]

OP has another thread related to this topic - https://forums.ni.com/t5/Instrument-Control-GPIB-Serial/Timeout-error-during-Fluke-8842a-GPIB-interf...

I think the problem might be related to the UGPlus USB/GPIB dll calls.  Its not clear what functions are being used from his code or if the timeout can be increased using the UGPlus USB - GPIB interface..  http://www.lqelectronics.com/Products/USBUG/UGPlus/UGPlus.html

You should try to send the commands to the Fluke using the UGPlus GUI first make sure the fluke works in the desired way.  From there move to using the DLLs. 

Provide us with more info...

- what commands are you sending?

- what are your end of line characters?  What does instrument expect and UGPlus support?

- the actual calls you are using in the DLL and the errors returned. 

You may need to get in contact with the UGPlus developpers to find out how to set bus timeouts.  

Craig