I am trying to control an external circuit by setting a voltage on AO1 on the PWR I/O connector. I am set up for an external trigger and change stimulus on my DUT, then supply the trigger to take a sweep. When set up to use the external trigger in this way, it appears that the voltage on AO1 is never updated. If I change the trigger to internal so that the PNA is constantly sweeping, then the voltage on AO1 does appear to change. Is there a way to update the voltage on AO1 while being externally triggered?
If you could be a bit more specific: how do you set the voltage on the AO1? by remote command or front panel interface? Do you set several values or just one or two values? How do you coordinate the setting with the triggering?
BTW, in the next firmware release (scheduled in April), there will be direct control of DC sources (external power supplies) and DC meters, including AO1 so you can set it to trigger each sweep or each point to a different value, or different value for each sweep, or different value on forward and reverse sweep.
I'm setting the AO1 voltage using SCPI commands. I did find a command that sets the mode of the AO outputs. CONT:AUX:OUTP1:MOD NOW. This command sets the voltage on the AO1 output immediately. The default sets the voltage after a sweep complete. This command has fixed my problem.