VISA: (Hex 0xBFFF0038) Bus error occurred during transfer.

[lplopez]

Hi,

I am trying to simultaneously communicate 3 different instruments (Keithley 2001, Keithley 2611A, Keithley 224) using GPIB (NI PCIe-GPIB). I checked the connection of these instrument using MAX (shown in the attached image) and it shows that they are connected. However, when I try to simultaneously run the said instruments, "VISA:  (Hex 0xBFFF0038) Bus error occurred during transfer" error occurred.

Also, I tried using just 2 instruments (Keithley 2001, Keithley 2611A) using GPIB (NI PCIe-GPIB), then I tried to communicate with Keithley 224 using a separate GPIB (GPIB-USB-HS), and it works well.

Question: Is there anyway to communicate 3 different instruments by just using GPIB (NI PCIe-GPIB)? I have also attached an actual image of the GPIB connections showing the (NI PCIe).

Thank you,

-Lorenzo

[Albert.Geven]

Hi

I would start with disabling parallel poll and slow down the bus speed especially for the Keithley 224.

This is probably not effecting speed a lot if there is any effect at all. It makes communication with the older device more stable.

If this works well you can increase the busspeed and try again.

The cabling looks OK except that I would use once cable less and plug the connectors on one of the instruments.

[cstorey]

Your wiring configuration is probably to blame.  The GPIB spec allow for 2m of cable between instruments and 20m total length.  It looks like you might have much more cable between the GPIB card and any instrument.  GPIB allows for daisy chain or star cabling, or any combination therof.  So you can run a cable directly to the first instrument, then a cable from first to second, second to third - or from GPIB-PCI directly to all 3 instruments or any combination.  Try to avoid long runs of cable without an instrument however.

Try re-routing cables and then I think things will work for you.

Craig