Some Win10 installations cannot measure VNAs

[feschmidt]

Using the new windows 10 PC, queries to the PNA5222A time out regularly.

Git hash: https://github.com/steelelab-delft/stlab/commit/21b2812833ec50117c3e99a5dd48d8705ebfc5da

[feschmidt]

this issue does not appear on the windows 7 PC (same hash: https://github.com/steelelab-delft/stlab/commit/21b2812833ec50117c3e99a5dd48d8705ebfc5da)

[feschmidt]

more specifically, it always gets stuck when reading the frequency values, right after setting the Trace o active:

CALC:PAR:CAT:EXT?
CALC1:PAR:SEL "CH1_S21"
CALC1:X?
<gets stuck here>

https://github.com/steelelab-delft/stlab/blob/21b2812833ec50117c3e99a5dd48d8705ebfc5da/devices/PNAN5221A.py#L27-L30

https://github.com/steelelab-delft/stlab/blob/21b2812833ec50117c3e99a5dd48d8705ebfc5da/devices/basepna.py#L239-L243

[feschmidt]

I can get it unstuck by using the win7PC to read the data again, or restarting the kernel on the win10PC.

query delay does not help much: When initializing the PNA the first time, sometimes I am able to read the data with query_delay, but also only the first time

[feschmidt]

current branch: https://github.com/steelelab-delft/stlab/tree/windows10

[feschmidt]

@adnsmora

[feschmidt]

the same thing happens using the Fieldfox PNA on some Win10PCs, not on others. It seems that Triggering the PNA causes it to reject subsequent reads, regardless of whether we use dev.Trigger() or dev.Trigger(block=False).

Triggering is possible multiple times, but reading afterwards not