Channel get() broken

[reneotten]

Steps to reproduce

dac.channels[6].volt.get()

Expected behaviour

Return voltage on channel

Actual behaviour

File "", line 1, in
dac.channels[6].volt.get()

File "c:\users\lab2\documents\python\qcodes\qcodes\instrument\parameter.py", line 405, in get_wrapper
e.args = e.args + ('getting {}'.format(self),)

File "c:\users\lab2\documents\python\qcodes\qcodes\instrument\parameter.py", line 361, in get_wrapper
# There might be cases where a .get also has args/kwargs

File "c:\users\lab2\documents\python\qcodes\qcodes\utils\command.py", line 177, in call
return self.exec_function(*args)

File "c:\users\lab2\documents\python\qcodes\qcodes\instrument_drivers\Harvard\FZJ_Decadac.py", line 234, in _get_volt
self._parent._write(self, DacBase._COMMAND_GET_VOLT)

File "c:\users\lab2\documents\python\qcodes\qcodes\instrument_drivers\Harvard\FZJ_Decadac.py", line 522, in _write
return self._parent._write(obj, cmd)

File "c:\users\lab2\documents\python\qcodes\qcodes\instrument_drivers\Harvard\FZJ_Decadac.py", line 661, in _write
self._set_channel(obj._parent, obj)

File "c:\users\lab2\documents\python\qcodes\qcodes\instrument_drivers\Harvard\FZJ_Decadac.py", line 640, in _set_channel
if self._set_slot(slot) or self.current_channel == None or self.current_channel.number != channel.number:

File "c:\users\lab2\documents\python\qcodes\qcodes\instrument_drivers\Harvard\FZJ_Decadac.py", line 623, in _set_slot
self._write(self, DacBase._COMMAND_SET_SLOT.format(slot.number))

File "c:\users\lab2\documents\python\qcodes\qcodes\instrument_drivers\Harvard\FZJ_Decadac.py", line 668, in _write
return self._read(self, len(cmd))

File "c:\users\lab2\documents\python\qcodes\qcodes\instrument_drivers\Harvard\FZJ_Decadac.py", line 685, in _read
result = super().ask_raw(buf_size)

File "c:\users\lab2\documents\python\qcodes\qcodes\instrument\visa.py", line 224, in ask_raw

File "C:\Users\lab2\anaconda3\envs\qcodes\lib\site-packages\pyvisa\resources\messagebased.py", line 563, in query
self.write(message)

File "C:\Users\lab2\anaconda3\envs\qcodes\lib\site-packages\pyvisa\resources\messagebased.py", line 223, in write
count = self.write_raw(message.encode(enco))

AttributeError: ("'int' object has no attribute 'encode'", 'getting DecaDac_Slot1_Chan1_volt')

[lankes-fzj]

@reneotten Please test if the problem is really solved because we don't have the hardware to it it ourselves.

[reneotten]

Neue Fehlermeldung nach
dac.channels[0].volt()

File "", line 1, in
dac.channels[0].volt()

File "c:\users\lab2\documents\python\qcodes\qcodes\instrument\parameter.py", line 283, in call
return self.get()

File "c:\users\lab2\documents\python\qcodes\qcodes\instrument\parameter.py", line 406, in get_wrapper
raise e

File "c:\users\lab2\documents\python\qcodes\qcodes\instrument\parameter.py", line 362, in get_wrapper
value = get_function(*args, **kwargs)

File "c:\users\lab2\documents\python\qcodes\qcodes\utils\command.py", line 177, in call
return self.exec_function(*args)

File "c:\users\lab2\documents\python\qcodes\qcodes\instrument_drivers\Harvard\FZJ_Decadac.py", line 239, in _get_volt
self._volt = int(buf[-self._BUF_SIZE+1:-1])

TypeError: ("'NoneType' object is not subscriptable", 'getting DecaDac_Slot0_Chan0_volt')

[lankes-fzj]

If the problem is solved, please test which format is used for the result of the function self._parent._read. For a raw voltage of for example 1234, the result should be the string: "d1234;". If the result is just the raw voltage ("1234"), the code has to be changed. This could have changed as the result of switching from serial to VisaInstrument (issue #2).

[reneotten]

It's solved, but I had to set the correct terminator ('\n') for the commands first.