No explicit timeout on client TCP/IP connections

[alexrudd2]

Versions

• Python: 3.10
• OS: MacOSX
• Pymodbus: b4f5a55
• Modbus Hardware (if used): any (I'm using a Productivity2000 PLC)

Pymodbus Specific

• Client: TCP/IP async

Description

The TCP/IP client connection code does not obey the timeout parameter inherited from ModbusBaseClient https://github.com/riptideio/pymodbus/blob/b4f5a558254f8242fd65fb49fe10f4f255610b32/pymodbus/client/base.py#L22-L28

This is because it relies on loop.create_connection(), which does not have any overall timeout parameter. A failed network call will eventually timeout in 45-120s, although I'm not sure which layer actually does it. (There is only ssl_handshake_timeout but this is very specific)

https://github.com/riptideio/pymodbus/blob/b4f5a558254f8242fd65fb49fe10f4f255610b32/pymodbus/client/tcp.py#L82-L89

(PR incoming)