Devices work in MAX, not with VISA calls

Question

Hello,
I'm currently attempting to control a pair of CSW5550 power supplies and having all sorts of problems.
On LAN, I have installed the devices as a TCPIP device to send SCPI commands to, as here:
Everything works great from the MAX window. I can send most queries with no problems, in particular the *IDN? query.
When I pop over to running a vi on the same VISA resource, however, I get very inconsistent results. Sometimes a read error, sometimes a write error, and sometimes I get a reading. Most often no error, but an error from the device and no data returned. Same thing for trying to perform other read operations, and it's clear from the response of the device (often 'invalid parameter', others) that the instrument is getting somewhat garbled commands.
The same thing goes if I try to run it over serial USB. This is what I'm running in the vis:
I mean, this is really basic stuff. I've tried varying the timing, newline termination, setting up and flushing the buffer.
So ... what is the difference between the queries MAX is executing and what I'm doing, and how can I troubleshoot it?
Thanks in advance,
C
PhD ChemE, CLD, Alliance Partner : www.interfaceinnovations.org

Answer 1

The devices are not connected in this picture. When connected, they validate and accept test panel commands fine.
PhD ChemE, CLD, Alliance Partner : www.interfaceinnovations.org