06-28-2017 10:49 AM
After a bit more research I found that the device would work if I enabled remote mode in the VISA control panel in NI-Max. I used the visa_gpib_control_ren VI to assert remote mode before using any of the device specific VIs and that fixed the issue.
It isn't clear why the Ethernet automatically operates in remote mode and the USB doesn't. I also noted that if I asserted remote mode using the VISA control panel in MAX before entering the address into the VISA control on my VI, the remote mode would be un-asserted when I finished typing in the GPIB address. Specifically when the box lost focus it would auto-capitalize the letters in the address - this action must communicate with the device in some way as this was when the remote mode would be un-asserted. I would prefer to have a greater understanding of some of the intricacies here for why it's behaving this way, but I'm not sure there's any to be found.
Problem solved.
06-28-2017 01:11 PM
Not really sure that I understand that as I have never needed to use that vi to communicate with these devices. I have verified the users manual documentation with several Agilent/Keysight 34970A Data Acquisition Switches in that these:
SYSTem:LOCal SYSTem:REMote
SYSTem:RWLock
commands only limit the RS-232 operations and NOT that of the GPIB (IEEE-488).
The only note in the users manual is that, "Only one interface can be enabled at a time."
SYSTem:INTerface {GPIB|RS232}
Perhaps that is the issue here. Both interfaces were connected, but only one may be enabled and the PWR ON State was probably set to last. Read the: 'Interface Configuration Commands' section of the users manual for more information.
04-11-2022 01:18 AM
Does the job. Although using Agilent Benchlink Datalogger 3 seems to reset this back to local mode.