Instrument cannot be controlled via GPIB-USB-HS cable

[$uper4i35]

I have 2 machines, machine A uses GPIB-USB-HS cable (cable A) on a USB port, connected to GPIB-GPIB cable, and then switch to another GPIB-USB-HS cable which connects machine B USB port. Both machines use ni488 17.5 version, and each one could be used as the controller to control the other one.

This system keeps working until I switch cable A to a new GPIB-USB-HS cable, let's mark cable A1. After switching this cable, the control seems to be a one-way communication.

if cable A1 connects machine A USB, cable B connects machine B USB, then machine A could control machine B, not the other way.

similarly, if cable A1 connects machine B USB, cable B connects machine A USB, then machine B could control machine A, not the other way.

 I also connects A1 directly to other machines GPIB ports directly, machine A could also control these GPIB machines well

I don't have gpib type machine to control machine A via cable A1, but it seems cable A1 can only support the controller side, not reversely

Does  anyone have the same problem and any solution ?

Thanks a lot

[psuedonym]

huh?

You can't just switch. USB isn't GPIB.

[Curt_C]

Hi,

I just want to get this clear. You have a PC with a GPIB-USB-HS plugged into a USB port.

A GPIB cable connected to that. Then another GPIB-USB-HS plugged into an instrument with the other end of the GPIB cable connected to that. Correct?

Why not just connect the instrument to the PC with a USB cable and use VISA?

Curt