[COM] Communication issue loop

[Robert]

For tests (in pymeasure) I would like to create a Visa-resource pointing to a loop as supported by PySerial.
Is there away to create a VISA resource string point to a serial.serial_for_url("loop://", timeout=0.2) object?

Or would there be another way to create a rm-object for a loop device?

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• Link to the documentation (if available): https://pyserial.readthedocs.io/en/latest/url_handlers.html#loop

Output of pyvisa-info

Machine Details:
   Platform ID:    Linux-6.4.3-arch1-2-x86_64-with-glibc2.37
   Processor:      

Python:
   Implementation: CPython
   Executable:     /usr/bin/python
   Version:        3.11.3
   Compiler:       GCC 13.1.1 20230429
   Architecture:   ('x86', 64)
   Build:          Jun  5 2023 09:32:32 (#main)
   Unicode:        UCS4

PyVISA Version: 1.13.1.dev29+g55f01db

Backends:
   ivi:
      Version: 1.13.1.dev29+g55f01db (bundled with PyVISA)
      Binary library: Not found
   py:
      Version: 0.7.0
      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
      TCPIP SOCKET: Available 
      GPIB INSTR: Available via Linux GPIB (b'4.3.5')
      GPIB INTFC: Available via Linux GPIB (b'4.3.5')
      VICP INSTR:
         Please install PyVICP to use this resource type.

[Matthieu Dartiailh]

Since VISA does not mandate the format of the serial board in the resource name you could use the URL and we could switch to using seiral.serial_for_url by default in PyVISA-py (with a version check). Could you test this solution and make a PR if it turns out ok ?

[Robert]

Thank you for the feedback and the proposal,
let me see if I can get it working and I will open a PR

You basically mean to modify SerialSession.after_parsing() to take serial.searial_for_url arguments?

[Matthieu Dartiailh]

Basically you can try replacing cls on line 87 by serial.serial_from_url.

[Robert]

Alright let me give it a try over the next days and report back..