communication problems with measurement devices (GPIB)

[samim_193]

Hello,

I'm using five measurement devices for my test rig and sometimes I have communication problems with two measurement devices. It is weird, because this problem is only sometimes and not always. I am controlling the devices with a VI that I have created on LabView 2014. The Keithley 2400 and the ILX Lightwave LDT 5910 b do not work fine. All measurement devices are connected with GPIB. To scan the measurement devices I am using NI MAX. Sometimes the devices are shown as Instrument 0/1/2/3/4 instead of their model name. In this case the communication is not working. Currently I am solving these communication problems by turning off and on the measurement devices or changing the device with an other.

Due to the fact that this can not be a solution, I want to know whether you can recommend an other way to solve this communication problem.

I hope, you can help me.

Best regards

Samim

[crossrulz]

1. Make sure all instruments have different GPIB addresses.  I doubt this is your problem, but do it anyways.

2. Make sure your GPIB instruments are connected in a chain (A->B, B->C, etc).  This makes the signals a little cleaner than the start configuration.

3. Make sure you are not using really long cables.  GPIB does have a limit on cable length.

[Dennis_Knutson]

Can you attach an image from MAX that shows what you mean by 0/1/2/3/4?