Error!!! 2 instruments for 1 GPIB slot

[TobyHex]

Hey Magou,
The simplest way to check your driver version is to open up Measurement & Automation Explorer(MAX) and expand the My System tree. From there navigate down to Software and expand that one as well. This might take a second to populate depending on your system. The next step is to scroll down to NI-488.2 and left click with your mouse on this icon, this will open up the Version, Description, and Path within the center tab.

Thanks and have a great day!
Regards,

Nicholas K

[magou]

Hi all,

my MAE version is 3.1.1.3004. Instrument 1 is HP 4284A Precision LCR meter. The GPIB cable using is DDK 408JE. I had print screen some of the problems i encountered.

I try to changed by I/O timeout from 1 sec to 1000 sec, but it still the same.

I also try to change the bus timing from 500ns to 2ua. but it still the same.

Everytime i click the "scan for instruments", the main page will shows different instruments.

Instrument 0 - address 5

Instrument 1 - address 17 (HP 4284A meter).

sometime will show only one of them, sometimes will show both or even more.

thanks to advise if any settings is wrong.

[Dennis_Knutson]

The version of MAX probably has nothing to do with your problem. It's the version of NI-488 that could possibly make a difference but I doubt it. The bus timing change was the only hope that I had that this could be a simple fix. I still think that the issue is electrical. You said you tried different cables and a different computer. I would assume that by different computer, you mean you tried a different controller in another pc. Trying the same controller in a different pc is not testing anything at all really. If you did test a different controller, then that leaves a defective instrument. This is a problem that I have seen before with instruments with a bad GPIB interface. Works fine by itself but the bad instrument's control lines have an issue. I asked once before if you could try it with a completely different set of instruments. Are you able to do that?

[magou]

I unable to try on another set of instruments. I will check the version of NI-488 again.

what do you mean by the bad instrument's control lines have an issue?

[Dennis_Knutson]

A GPIB bus has 8 data lines, 3 handshaking lines, and 5 bus management lines. As mentioned by Steven, before any data is sent/received (with an *IDN?) query, instruments are detected whit the handshaking/management lines. An instrument could have one of the lines stuck and this could prevent another instrument being correctly detected.