MAX reports error on scanning

[Paul_Knight_Lockheed_Mart]

I have the following GPIB setup in a daisy chain

TDS3052            Addr:3

Agilent 33220A   Addr:10

Agilent E3649     Addr:20

Ando 6317B        Addr:30

Max scans these instruments without any problems.

I add a Lambda Gen series power supply at Addr:25, Max scans without a problem.

If I remove the Lambda and add a Cohernet LabMax Power Meter at Addr:15, Max scans without a problem.

However if I add both the Lambda and the Cohernet, Max reports: "An error occurred while scanning".

I have also tried configuring the GPIB network in a "Star" and get the same error.

I have attached a NI SPY report for both a pass and a failure.  Then only error I can see is the second statement ibconfig sets iberr to 1.  But the second statement in the pass file also sets iberr to 1.

What is MAX seeing as an error?

[muks]

What is timeout you have set?

[Paul_Knight_Lockheed_Mart]

I am using a National Instrument USB-GPIB-HS as my interface.  Timeout is set to the default 10 seconds.

Paul

[muks]

Can you change  it to maximum possible and check whether you still have this issue

[Paul_Knight_Lockheed_Mart]

I changed it to maximum (1000 sec).  There was no change in the error.  As soon as a press the scan for instruments it gets an error, no waiting for the timeout.

[Paul_Knight_Lockheed_Mart]

Using the Interactive Control feature of MAX and hand entering the commands, with both instruments installed I get an ECIC error that I cannot clear out.

[Dennis_Knutson]

Errors of this nature are often caused by a hardware problem. It could be a bad cable or a bad GPIB interface on one of the instruments. Also, check to make sure you are not exceeding the maximum cable length - 20m.

[JÞB]

Your capture shows that "Attention" is asserted.  In this case it seams as if the GPIB interfaces in the equipment are not playing nice.

For HS applications there are additional physical restrictions:

• All devices in the system must be powered on.
• Cable lengths must be as short as possible with up to a maximum of 15 m of cable for each system.
• There must be at least one equivalent device load per meter of cable.

I'd suggest that you look into your setup and replace your cables with the shortest possible cables.  you might need to add a bus expander to get everyone to play nice. 

[Paul_Knight_Lockheed_Mart]

Total cable length is around 12 meters and they are as short as I can get them between instruments.

[JÞB]

Well Paul, you've got 12 meters and 6 devices.  Sounds like its time for a bus expander.   The NI 120B is a good fit.  But, first I would look into the equipment documentation and see if the non-agilent devices are violating 488.2 handshaking line physical requirenents.

I'd assume the Agilent and the Textronics devices are up to snuff but you never know with some of the smaller manufacturers