`dond` finishes but the measurement in reality is incomplete (for Agilent N9928 VNA)

[paniash]

Hi,

I'm not entirely sure if this is a bug from qcodes side or the driver for said VNA but I noticed that often times when running a dond sweep, it completes it on the code side but when referring to the measuring instrument, it is still incomplete.

One particular example is like so: I've set about 1000 averages for a VNA measurement and when setting the same with qcodes and running a dond sweep, I often find the measurement completes in about 5 mins (code side) whereas when looking at the VNA, the measurement is nowhere near complete.

The above figure gives a decent idea of the issue. It's clear the measurement isn't complete but dond still shows that it indeed is.

I'd appreciate any help on this matter. Thanks.

[jenshnielsen]

Ashish Panigrahi (@paniash) From the information supplied I don't have a good idea what is going on. It could perhaps be related to the driver reading back data too early because its not checking the right conditions so trying to compare the driver to the manual may be one way.

I would probably suggest investigating if logging messages can tell you something. There are some guides here on how you can use logging https://microsoft.github.io/Qcodes/examples/logging/index.html It is likely that you would also want to extend with more log messages around reading and writing from the instrument.