Kepco SNR 488-8 Too Many listners on GPIB

[GrahamBest]

Hello,

I am having problems connecting to a Kepco SNR 488-8 Power Controller via the GPIB bus. The odd thing is that I was able to connect to it before...

Here are the steps to reproduce the error:

• Start NI MAX
• Click on My System -> Device and Interfaces -> PCI-GPIB "GPIB0"
• On the "Properties" tab, click on the button "Scan for Instruments"
• Get an error that says "Too many listeners on GPIB"

This is what I've tried to fix the error:

• I verified that the PCI-GPIB is set to address 0.
• I also verified that the address for the Kepco SNR 488-8 is address 4.
• I can't click on "Restore Defaults" button for the GPIB card as it's grayed out.
• I tried two different GPIB cables connecting directly from the PC to the test equipment, so it's unlikely that it's a bad cable.
• I updated to the latest version of NI MAX v5.5.0f0.
• I tried the NI-488.2 troubleshooting utility. Both of the options passed.
• I also collected a trace if that helps.

I had the Agilent VISA installed at one point, but I uninstalled it so the NI VISA should be the only one left.

Is there anything else I can try?

Thank you,

Graham Best

[Dennis_Knutson]

It sounds to me that you have a hardware fault with the Instrument or the controller. Is there another instrument that you can connect?

p.s. The version of MAX is not that relevant. What's your version of NI-488.2?

[GrahamBest]

The version of NI-488.2 is 3.1.1.

I was able to connect to another test equipment device. I also tried to connect to another Kepco SNR 488-8 power controller and had the same issue. Both of these units are functional when they are connected to a much older computer.

[Dennis_Knutson]

You could try slowing down the bus timing. This is a setting of the controller's properties in MAX.

[GrahamBest]

I tried changing the bus timing from 500 nanoseconds to 2 microseconds and the instrument was still not recognized.