Cannot connect to APTPiezoStage with open_serial

[dupuisni]

Hi,

I am having some issues to use APTPiezoStage. I am trying to connect using open_serial which always raise TypeError: can't concat str to bytes. I tried connecting to other non-APT Thorlabs instruments using the same method and that works great. The instrument I am trying to connect is a 3-channel closed-loop Piezo controller (BPC303).

[scasagrande]

Can you give me a full traceback so I can see where the TypeError is being raised?

[crazy4pi314]

Which version of python are you using? I have had problems with string encoding with the changes in 3, and have a fix I need to PR, but haven't bc I didn't get it fully tested yet.

[dupuisni]

I use python 3.7. Also tried with 3.4, and 3.6 but no luck. Here is the full traceback:

Traceback (most recent call last):
File "ex_BPC303.py", line 9, in
boa = BPC303.open_serial(vid=vid, pid=pid, baud=115200)
File "/home/ndupuis/Documents/testing_Thorlabs/py37_ik/lib/python3.7/site-packages/instrumentkit-0.1.1-py3.7.egg/instruments/abstract_instruments/instrument.py", line 525, in open_serial
File "/home/ndupuis/Documents/testing_Thorlabs/py37_ik/lib/python3.7/site-packages/instrumentkit-0.1.1-py3.7.egg/instruments/thorlabs/bpc303.py", line 34, in init
File "/home/ndupuis/Documents/testing_Thorlabs/py37_ik/lib/python3.7/site-packages/instrumentkit-0.1.1-py3.7.egg/instruments/thorlabs/thorlabsapt.py", line 110, in init
File "/home/ndupuis/Documents/testing_Thorlabs/py37_ik/lib/python3.7/site-packages/instrumentkit-0.1.1-py3.7.egg/instruments/thorlabs/_abstract.py", line 59, in querypacket
File "/home/ndupuis/Documents/testing_Thorlabs/py37_ik/lib/python3.7/site-packages/instrumentkit-0.1.1-py3.7.egg/instruments/abstract_instruments/instrument.py", line 134, in query
File "/home/ndupuis/Documents/testing_Thorlabs/py37_ik/lib/python3.7/site-packages/instrumentkit-0.1.1-py3.7.egg/instruments/abstract_instruments/comm/abstract_comm.py", line 233, in query
File "/home/ndupuis/Documents/testing_Thorlabs/py37_ik/lib/python3.7/site-packages/instrumentkit-0.1.1-py3.7.egg/instruments/abstract_instruments/comm/serial_communicator.py", line 191, in _query
File "/home/ndupuis/Documents/testing_Thorlabs/py37_ik/lib/python3.7/site-packages/instrumentkit-0.1.1-py3.7.egg/instruments/abstract_instruments/comm/abstract_comm.py", line 218, in sendcmd
File "/home/ndupuis/Documents/testing_Thorlabs/py37_ik/lib/python3.7/site-packages/instrumentkit-0.1.1-py3.7.egg/instruments/abstract_instruments/comm/serial_communicator.py", line 175, in _sendcmd
TypeError: can't concat str to bytes

[scasagrande]

instrumentkit-0.1.1

are you sure you have the latest version installed

[dupuisni]

Indeed, for that test I branched from ch-thorlabs-mdt693B, did not realize that it was not the latest version. Here is the full traceback with the latest version:

---

TypeError Traceback (most recent call last)
/home/ndupuis/Documents/testing_Thorlabs/InstrumentKit/test_ik.py in ()
1 import instruments as ik
2
----> 3 test=ik.thorlabs.APTPiezoStage.open_serial(vid=int('0403',16),pid=int('faf0',16))

/home/ndupuis/Documents/testing_Thorlabs/InstrumentKit/instruments/abstract_instruments/instrument.py in open_serial(cls, port, baud, vid, pid, serial_number, timeout, write_timeout)
527 write_timeout=write_timeout
528 )
--> 529 return cls(ser)
530
531 @classmethod

/home/ndupuis/Documents/testing_Thorlabs/InstrumentKit/instruments/thorlabs/thorlabsapt.py in init(self, filelike)
108 )
109 hw_info = self.querypacket(
--> 110 req_packet, expect=_cmds.ThorLabsCommands.HW_GET_INFO)
111
112 self._serial_number = str(hw_info.data[0:4]).encode('hex')

/home/ndupuis/Documents/testing_Thorlabs/InstrumentKit/instruments/thorlabs/_abstract.py in querypacket(self, packet, expect)
57 :rtype: ThorLabsPacket
58 """
---> 59 resp = self.query(packet.pack())
60 if not resp:
61 if expect is None:

/home/ndupuis/Documents/testing_Thorlabs/InstrumentKit/instruments/abstract_instruments/instrument.py in query(self, cmd, size)
132
133 if ack_expected_list[0] is None: # Case no ACK
--> 134 value = self._file.query(cmd, size)
135 else: # Case with ACKs
136 _ = self._file.query(cmd, size=0) # Send the cmd, don't read

/home/ndupuis/Documents/testing_Thorlabs/InstrumentKit/instruments/abstract_instruments/comm/abstract_comm.py in query(self, msg, size)
231 if self.debug:
232 self._logger.debug(" <- %s", repr(msg))
--> 233 resp = self._query(msg, size)
234 if self.debug:
235 self._logger.debug(" -> %s", repr(resp))

/home/ndupuis/Documents/testing_Thorlabs/InstrumentKit/instruments/abstract_instruments/comm/serial_communicator.py in _query(self, msg, size)
189 :rtype: str
190 """
--> 191 self.sendcmd(msg)
192 return self.read(size)

/home/ndupuis/Documents/testing_Thorlabs/InstrumentKit/instruments/abstract_instruments/comm/abstract_comm.py in sendcmd(self, msg)
216 if self.debug:
217 self._logger.debug(" <- %s", repr(msg))
--> 218 self._sendcmd(msg)
219
220 def query(self, msg, size=-1):

/home/ndupuis/Documents/testing_Thorlabs/InstrumentKit/instruments/abstract_instruments/comm/serial_communicator.py in _sendcmd(self, msg)
173 :param str msg: The command message to send to the instrument
174 """
--> 175 msg += self._terminator
176 self.write(msg)
177

TypeError: can't concat str to bytes

[scasagrande]

Looks like we might have to change ThorLabsPacket line resp = self.query(packet.pack()) to use send_raw as the underlying implementation of query uses sendcmd, which is looking for a str input. I believe packet.pack() is bytes, and I imagine we shouldn't be appending a termination character anyways.

[crazy4pi314]

Let me look at my stuff tonight, I did fix this at one point for talking to the k100 cubes. Ill make a new PR then to fix it hopefully then.

[dupuisni]

Looks like the issue has been solved already in feature-apt-tables branch. I just tested and no more TypeError.

[scasagrande]

I'll try to cherry pick that fix into master then 👌

[scasagrande]

I've resurrected PR #167 in an attempt to address this issue. The biggest functional difference is going to be master branch has been merged in. If I don't end up hearing anything I'll merge it into develop shortly to be staged with a few other changes for a 0.5.0 release.

[scasagrande]

I haven't heard anything, so that branch is now merged into the develop branch.