Issue with nixnet python driver

[Franky_31]

Hi everyone,

I'm trying to make a simple Python script to log CAN frames using NI-XNET driver and a USB-8502 CAN module.

I wrote a some code to display all the CAN frames transiting on the bus.

import nixnet
from nixnet import system
from nixnet import constants
from nixnet import types
import time

# Get CAN interface name
can_interfaces = nixnet.system.System().intf_refs_can

can_list = []
for can_interface in can_interfaces:
    can_list.append(can_interface)

can_interface = can_list[0]
print(can_interface)

can_database = ':can_fd_brs:'
can_cluster = ''
with nixnet.FrameInStreamSession(str(can_interface), str(can_database), str(can_cluster)) as input_session:
    input_session.intf.can_term = constants.CanTerm.OFF
    input_session.intf.baud_rate = 1000000
    input_session.intf.can_fd_baud_rate = 4000000

    input_session.start()

    for i in range(0, 10):
        frames = input_session.frames.read(10000, constants.TIMEOUT_NONE)
        for frame in frames:
            print(frame)
        time.sleep(0.1)

When I execute this code, I have the following error :

Traceback (most recent call last):
  File "D:\my_path\main.py", line 27, in <module>
    input_session.start()
  File "D:\Programs\Python\Python39\lib\site-packages\nixnet\_session\base.py", line 165, in start
    _funcs.nx_start(self._handle, scope)
  File "D:\Programs\Python\Python39\lib\site-packages\nixnet\_funcs.py", line 395, in nx_start
    _errors.check_for_error(result.value)
  File "D:\Programs\Python\Python39\lib\site-packages\nixnet\_errors.py", line 18, in check_for_error
    status = status_to_string(error_code)
  File "D:\Programs\Python\Python39\lib\site-packages\nixnet\_errors.py", line 33, in status_to_string
    status_string = buffer_ctypes.value.decode("ascii")
UnicodeDecodeError: 'ascii' codec can't decode byte 0xe9 in position 31: ordinal not in range(128)

If I don't specify database and cluster in the FrameInStreamSession() call, I do not have error, but by default the configuration is CAN, not CAN FD + BRS.

Is this a known issue, and does anybody know how to solve this problem ?

I'm using Python 3.9.12 and nixnet 0.3.2.

Thanks to all for the support

Kind regards

[kdl1021]

Always ensure that your hardware and network configurations are correct and that the nixnet library supports the CAN interface you are working with.

Here is the revised code:

from nixnet import system, constants, types
import time

# Get CAN interface name
can_interfaces = system.System().intf_refs_can

can_list = [can_interface for can_interface in can_interfaces]

# Ensure there is at least one CAN interface
if not can_list:
    raise Exception("No CAN interfaces found")

can_interface = can_list[0]
print(can_interface)

# Replace with actual database and cluster names
can_database = ':can_fd_brs:'  # Placeholder, replace with actual database
can_cluster = ''  # Placeholder, replace with actual cluster name

with system.FrameInStreamSession(str(can_interface), str(can_database), str(can_cluster)) as input_session:
    input_session.intf.can_term = constants.CanTerm.OFF
    input_session.intf.baud_rate = 1000000
    input_session.intf.can_fd_baud_rate = 4000000

    input_session.start()

    for _ in range(10):
        frames = input_session.frames.read(10000, constants.TIMEOUT_NONE)
        for frame in frames:
            print(frame)
        time.sleep(0.1)

I really hope this helps!