[COM] query_binary_values timeout with HP 1660C logic analyzer using TCPIP SOCKET

[fenugrec]

Instrument details

• Model: HP 1660C
• Communication: TCPIP0::192.168.3.60::5025::SOCKET
• Link to the documentation (if available): https://www.keysight.com/us/en/assets/9018-01010/programming-guides/9018-01010.pdf

Output of pyvisa-info

Machine Details:
Platform ID: Linux-6.13.5-arch1-1-x86_64-with-glibc2.41
Processor:

Python:
Implementation: CPython
Executable: /usr/bin/python
Version: 3.13.2
Compiler: GCC 14.2.1 20250128
Architecture: ('x86', 64)
Build: Feb 5 2025 08:05:21 (#main)
Unicode: UCS4

PyVISA Version: 1.14.1

Backends:
ivi:
Version: 1.14.1 (bundled with PyVISA)
Binary library: Not found
py:
Version: 0.7.2
TCPIP INSTR: Available
Resource discovery:
- VXI-11: partial (psutil not installed)
- hislip: disabled (zeroconf not installed)
TCPIP SOCKET: Available
ASRL INSTR:
Please install PySerial (>=3.0) to use this resource type.
No module named 'serial'
USB INSTR:
Please install PyUSB to use this resource type.
No module named 'usb'
USB RAW:
Please install PyUSB to use this resource type.
No module named 'usb'
VICP INSTR:
Please install PyVICP to use this resource type.
GPIB INSTR:
Please install linux-gpib (Linux) or gpib-ctypes (Windows, Linux) to use this resource type. Note that installing gpib-ctypes will give you access to a broader range of functionalities.
No module named 'gpib'
GPIB INTFC:
Please install linux-gpib (Linux) or gpib-ctypes (Windows, Linux) to use this resource type. Note that installing gpib-ctypes will give you access to a broader range of functionalities.
No module named 'gpib'

problem

Hi, I'm having issues retrieving block data from an HP logic analyzer. This works :

read_termination='\n'` 
print(la.query('*idn?'))

but it seems that setting read_termination breaks every manner of binary transfer. I lost track of everything I tried, but the one that I think is the closest that should work :

>>> pyvisa.log_to_screen()
>>> print(la.query('*idn?'))
2025-03-07 12:50:10,432 - pyvisa - DEBUG - TCPIP0::192.168.3.60::5025::SOCKET - reading 20480 bytes (last status <StatusCode.success_max_count_read: 1073676294>)
HEWLETT PACKARD,1660C,0,REV 02.00
>>> plist=la.query_binary_values(':syst:data?')
2025-03-07 12:50:25,985 - pyvisa - DEBUG - TCPIP0::192.168.3.60::5025::SOCKET - reading 20480 bytes (last status <StatusCode.success_max_count_read: 1073676294>)
2025-03-07 12:50:26,048 - pyvisa - DEBUG - TCPIP0::192.168.3.60::5025::SOCKET - reading 1044 bytes (last status None)
2025-03-07 12:50:26,073 - pyvisa - DEBUG - TCPIP0::192.168.3.60::5025::SOCKET - reading 1018 bytes (last status <StatusCode.success_termination_character_read: 1073676293>)
2025-03-07 12:50:26,195 - pyvisa - DEBUG - TCPIP0::192.168.3.60::5025::SOCKET - reading 24 bytes (last status <StatusCode.success_termination_character_read: 1073676293>)
2025-03-07 12:50:28,207 - pyvisa - DEBUG - TCPIP0::192.168.3.60::5025::SOCKET - exception while reading: VI_ERROR_TMO (-1073807339): Timeout expired before operation completed.
Buffer content: bytearray(b'\x00\x01\x00\x00\x00\x00\x00\x06\x00\x02HP-IB     
[ ... trimmed most of it]
x00\x00\n')
Traceback (most recent call last):
  File "<python-input-91>", line 1, in <module>
    plist=la.query_binary_values(':syst:data?')
  File "/usr/lib/python3.13/site-packages/pyvisa/resources/messagebased.py", line 750, in query_binary_values
    return self.read_binary_values(
           ~~~~~~~~~~~~~~~~~~~~~~~^
        datatype,
        ^^^^^^^^^
    ...<5 lines>...
        chunk_size,
        ^^^^^^^^^^^
    )
    ^
  File "/usr/lib/python3.13/site-packages/pyvisa/resources/messagebased.py", line 603, in read_binary_values
    self.read_bytes(expected_length - len(block), chunk_size=chunk_size)
    ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/site-packages/pyvisa/resources/messagebased.py", line 370, in read_bytes
    chunk, status = self.visalib.read(self.session, size)
                    ~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/site-packages/pyvisa_py/highlevel.py", line 520, in read
    return data, self.handle_return_value(session, status_code)
                 ~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/site-packages/pyvisa/highlevel.py", line 251, in handle_return_value
    raise errors.VisaIOError(rv)
pyvisa.errors.VisaIOError: VI_ERROR_TMO (-1073807339): Timeout expired before operation completed.

I also tried specifying expect_termination=0 because I can see the trailing '\n' in there, but same result.
Any suggestions appreciated !