pyvisa/pyvisa-py

[COM] Communication issue with PL303QMD-P using TCPIP(RAW)

lambcutlet opened this issue · 4 comments

lambcutlet commented

Hi,
I'm attempting to link a few bits of kit together using pyvisa.
I'm stumped at my PSU, When performing list resources its listed as 'TCPIP::192.168.1.124::INSTR'
But the manual says when using Ethernet, use TCPIP address, port & RAW protocol.
As i understand pyvisa this should be in the format of 'TCPIP::192.168.1.124::9221::SOCKET'.

Using 'TCPIP::192.168.1.124::INSTR' I get this error message:

('ASRL/dev/ttyUSB1::INSTR', 'ASRL/dev/ttyUSB0::INSTR', 'ASRL/dev/ttyACM1::INSTR', 'TCPIP::192.168.1.124::INSTR')
ASRL/dev/ttyUSB1::INSTR :device not responding
ASRL/dev/ttyUSB0::INSTR :device not responding
ASRL/dev/ttyACM1::INSTR :device not responding
TCPIP::192.168.1.124::INSTR :device not responding
quitting!
Exception ignored in atexit callback: <function ResourceManager.new..call_close at 0x7fc3f2559d00>
Traceback (most recent call last):
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa/highlevel.py", line 3014, in call_close
meth()
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa/highlevel.py", line 3073, in close
resource.close()
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa/resources/resource.py", line 319, in close
self.visalib.close(self.session)
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/highlevel.py", line 439, in close
return self.handle_return_value(session, sess.close())
^^^^^^^^^^^^
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/tcpip.py", line 481, in close
self.interface.destroy_link(self.link)
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/protocols/vxi11.py", line 344, in destroy_link
return self.make_call(
^^^^^^^^^^^^^^^
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/protocols/rpc.py", line 478, in make_call
return super(RawTCPClient, self).make_call(proc, args, pack_func, unpack_func)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/protocols/rpc.py", line 236, in make_call
result = unpack_func()
^^^^^^^^^^^^^
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/protocols/vxi11.py", line 167, in unpack_device_error
return self.unpack_int()
^^^^^^^^^^^^^^^^^
File "/usr/lib64/python3.11/xdrlib.py", line 171, in unpack_int
raise EOFError
EOFError:
Exception ignored in: <function Resource.del at 0x7fc3f255ad40>
Traceback (most recent call last):
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa/resources/resource.py", line 180, in del
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa/resources/resource.py", line 319, in close
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/highlevel.py", line 439, in close
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/tcpip.py", line 481, in close
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/protocols/vxi11.py", line 344, in destroy_link
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/protocols/rpc.py", line 478, in make_call
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/protocols/rpc.py", line 236, in make_call
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/protocols/vxi11.py", line 167, in unpack_device_error
File "/usr/lib64/python3.11/xdrlib.py", line 171, in unpack_int
EOFError:

Using 'TCPIP::192.168.1.124::9221::SOCKET'

It just times out. I've tried TCPIP0 & TCPIP1 as well all result in the same failure.
I have also tried playing around with terminations but they make no difference.
I have also attempted 'socket' as I see a few other people have shown this method as functional and in my case it does work.
Can you provide an insight to get this PSU talking to pyvisa?

Here's my code :

import pyvisa
rm = pyvisa.ResourceManager('@py')
resources = rm.list_resources()
print(resources)
psu_tti = False
psu_tti_ID = 'THURLBY THANDAR, PL303QMD-P, 371832, 3.01-4.06\n'
for devices in resources:
try:
#if devices == 'TCPIP::192.168.1.124::INSTR':
#devices = 'TCPIP::192.168.1.124::9221::SOCKET'
dev = rm.open_resource(devices)
dev.query_delay = 0.1
dev.timeout = 5000
response = dev.query("*IDN?")
time.sleep(0.1)
print(response)
# TTI PL303QMD-P
if response:
psu_tti = dev
print(" ", psu_tti_ID, " connected to:\n ", devices, "\n")
except:
print(devices, " :device not responding")
pass
#print(psu_tti, " :dmm status check")
#if psu_tti: print("psu_tti: ", psu_tti.query("v1?"))
print("quitting!")
quit()

Instrument details

Output of pyvisa-info

`pyvisa-info
/home/kp/.local/lib/python3.11/site-packages/gpib_ctypes/gpib/gpib.py:54: UserWarning: GPIB library not found. Please manually load it using _load_lib(filename). All GPIB functions will raise OSError until the library is manually loaded.
warnings.warn(message)
Machine Details:
Platform ID: Linux-6.4.10-200.fc38.x86_64-x86_64-with-glibc2.37
Processor:

Python:
Implementation: CPython
Executable: /usr/bin/python3
Version: 3.11.4
Compiler: GCC 13.1.1 20230511 (Red Hat 13.1.1-2)
Bits: 64bit
Build: Jun 7 2023 00:00:00 (#main)
Unicode: UCS4

PyVISA Version: 1.13.0

Backends:
ivi:
Version: 1.13.0 (bundled with PyVISA)
Binary library: Not found
py:
Version: 0.6.3
ASRL INSTR: Available via PySerial (3.5)
USB INSTR: Available via PyUSB (1.2.1). Backend: libusb1
USB RAW: Available via PyUSB (1.2.1). Backend: libusb1
TCPIP INSTR: Available
Resource discovery:
- VXI-11: ok
- hislip: ok
VICP INSTR:
Please install PyVICP to use this resource type.
TCPIP SOCKET: Available
GPIB INSTR:
gpib_ctypes is installed but could not locate the gpib library.
Please manually load it using:
gpib_ctypes.gpib.gpib._load_lib(filename)
before importing pyvisa.`

Sorry long message and rubbish formatting.

lambcutlet commented

Hi,
Made a little progress and managed to get a response before an EOF error

Code:

from datetime import datetime
import pyvisa
rm = pyvisa.ResourceManager('@py')
resources = rm.list_resources()

def debug(*args):
    print(datetime.now(), *args)

devices = 'TCPIP0::192.168.1.124::9221::INSTR' #)#, , , 'TCPIP0::192.168.1.124::9221::SOCKET'

try:
    dev = rm.open_resource(devices)
    dev.query_delay = 0.1
    dev.timeout = 1000
    dev.read_termination = None
    dev.write_termination = '\n'
    response = dev.query("*IDN?")
    print("response: ", response)
except Exception as ex:
    debug(ex)
except:
    print(devices, " :device not responding")
    pass

print("quitting!\n")
quit()

Error message:

response: THURLBY THANDAR, PL303QMD-P, 371832, 3.01-4.06
quitting!

Exception ignored in atexit callback: <function ResourceManager.new..call_close at 0x7f35f8a85d00>
Traceback (most recent call last):
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa/highlevel.py", line 3014, in call_close
meth()
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa/highlevel.py", line 3073, in close
resource.close()
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa/resources/resource.py", line 319, in close
self.visalib.close(self.session)
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/highlevel.py", line 439, in close
return self.handle_return_value(session, sess.close())
^^^^^^^^^^^^
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/tcpip.py", line 481, in close
self.interface.destroy_link(self.link)
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/protocols/vxi11.py", line 344, in destroy_link
return self.make_call(
^^^^^^^^^^^^^^^
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/protocols/rpc.py", line 478, in make_call
return super(RawTCPClient, self).make_call(proc, args, pack_func, unpack_func)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/protocols/rpc.py", line 236, in make_call
result = unpack_func()
^^^^^^^^^^^^^
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/protocols/vxi11.py", line 167, in unpack_device_error
return self.unpack_int()
^^^^^^^^^^^^^^^^^
File "/usr/lib64/python3.11/xdrlib.py", line 171, in unpack_int
raise EOFError
EOFError:

Exception ignored in: <function Resource.del at 0x7f35f8a86d40>
Traceback (most recent call last):
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa/resources/resource.py", line 180, in del
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa/resources/resource.py", line 319, in close
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/highlevel.py", line 439, in close
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/tcpip.py", line 481, in close
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/protocols/vxi11.py", line 344, in destroy_link
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/protocols/rpc.py", line 478, in make_call
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/protocols/rpc.py", line 236, in make_call
File "/home/kp/.local/lib/python3.11/site-packages/pyvisa_py/protocols/vxi11.py", line 167, in unpack_device_error
File "/usr/lib64/python3.11/xdrlib.py", line 171, in unpack_int
EOFError:

lambcutlet commented

More info using

pyvisa.log_to_screen()

Turns out this request 'TCPIP0::192.168.1.124::9221::INSTR' is detected as RAW and is redirected to port 111. It only ever receives *IDN? info regardless of which ever command is sent. Obviously not the correct way forward.

Using 'TCPIP::192.168.1.124::9221::SOCKET' I now see this response below. Where there appears to be data in the buffer but because there isn't a terminator it times out, my guess. Need to find away of writing and reading.
I saw an 'issue' earlier today but i can't find it now. About a read() command needing modified adding an if-else statement to prevent crashes. Could this be the issue here?

2023-08-20 20:26:06,910 - pyvisa - DEBUG - TCPIP0::192.168.1.124::9221::SOCKET - opening ...
2023-08-20 20:26:06,912 - pyvisa - DEBUG - TCPIP0::192.168.1.124::9221::SOCKET - is open with session 6286428
2023-08-20 20:26:07,012 - pyvisa - DEBUG - TCPIP0::192.168.1.124::9221::SOCKET - reading 20480 bytes (last status <StatusCode.success_max_count_read: 1073676294>)
2023-08-20 20:26:08,021 - pyvisa - DEBUG - TCPIP0::192.168.1.124::9221::SOCKET - exception while reading: VI_ERROR_TMO (-1073807339): Timeout expired before operation completed.
Buffer content: bytearray(b'')
2023-08-20 20:26:08.021145 VI_ERROR_TMO (-1073807339): Timeout expired before operation completed.
2023-08-20 20:26:08,021 - pyvisa - DEBUG - Closing ResourceManager (session: 9578851)
2023-08-20 20:26:08,021 - pyvisa - DEBUG - TCPIP0::192.168.1.124::9221::SOCKET - closing
2023-08-20 20:26:08,021 - pyvisa - DEBUG - TCPIP0::192.168.1.124::9221::SOCKET - is closed

lambcutlet commented

Got it.
Address = 'TCPIP0::192.168.1.124::9221::SOCKET'
read_termination = '\r\n'

Read out each byte from the buffer and noticed '\r\n' at the end.

MatthieuDartiailh commented

Happy you figured out a solution.