I like to control a VISA device (PAX1000 polarimeter).
I start programming under Windows using ni-visa backend for pyvisa and the communication works perfectly. Also if I use the pyvisa-py backend with winusb driver (changing the driver with zadig), everything works ok.
Then I move the polarimeter to a Raspberry Pi, using also the pyvisa lib, but with pyvisa-py backend (ni-visa is not available for ARM). Most of the commands works as expected and I get the expected answer. But there where also some commands, whichs doesent work. For example if I use
inst.write('SENS:CALC 9;:INP:ROT:STAT 1')
I get:
(40, <StatusCode.success: 0>)
The device doesn't set the value. (The same code runs fine under Windows.)
So I have no idea, whats going on.
Samplecode:
import pyvisa
import numpy as np
#rm = pyvisa.ResourceManager('@py')
rm = pyvisa.ResourceManager()
rm.list_resources()
#ni-visa
inst = rm.open_resource('USB0::0x1313::0x8031::M00587150::INSTR')
#pyvisa-py
#inst = rm.open_resource('USB0::4883::32817::M00587150::0::INSTR')
print(inst.query('*IDN?'))
print(inst.write('SENS:CALC 9;:INP:ROT:STAT 1'))
print(inst.query('SENS:DATA:LAT?'))
