Open function returns always None

[nzaquini]

Hi, I'm moving my first steps in trying to connect to an EtherCAT adapter.

I started writing some basic code (see below). My problem is that the master.open(adapter.name) function returns always None instead of a valid boolean.

I have the same result both on Windows 11 and on the WSL virtual machine. I don't know why open() is returning None. I've installed Npcap 1.79 with WinPcap Api-compatible Mode flag.

Thanks for any help, Nicola

# Test Pysoem Code
import pysoem
import time

def main():
  adapters = pysoem.find_adapters()

  # Initialize the EtherCAT master
  master = pysoem.Master()

  for i, adapter in enumerate(adapters):
      print('Adapter {}'.format(i))
      print('  name: {}'.format(adapter.name))
      print('  description: {}'.format(adapter.desc))

      # Scan for slaves
      try:
          master.close()
          time.sleep(2)
          masterOpenResult = master.open(adapter.name)
          if masterOpenResult == None:
              print('EtherCAT Master open error (value: None)')
          elif masterOpenResult:
              print('EtherCAT Master opened successfully')

              # Find and initialize all connected slaves
              if master.config_init():
                  print(f'Found {len(master.slaves)} slaves')

                  # Print some basic information about each slave
                  for idx, slave in enumerate(master.slaves):
                      print(f'Slave {idx+1} - Name: {slave.name}, Output size: {slave.output_size}, Input size: {slave.input_size}')

                  # Close the master
                  master.close()
                  print('EtherCAT Master closed')
              else:
                  print('No slaves found or failed to configure')
          else:
              print('Failed to open EtherCAT master')
              master.find_adapters()
      except pysoem.SOEMError as e:
          print(f'SOEMError: {e}')
      except Exception as e:
          print(f'Unexpected error: {e}', file=sys.stderr)

if __name__ == '__main__':
    main()

[bnjmnp]

Hi, The open() function is not supposed to return anything other than None. If an error occurs the function will raise an exception, thus you don't need to check the return value.

[nzaquini]

Thank you very much.