Closed ekw closed 7 years ago
Generally, PLCs use the EtherNet/IP CIP "Implicit" or "Connected" requests via UDP/IP for real-time communication within the factory-floor LAN. The cpppo API doesn't implement this part of the protocol. It implements the TCP/IP "Unconnected" or "Explicit" request/response part of the protocol. This is generally the one used by computers that interact with PLCs (quite often from outside the factory-floor LAN).
So, usually it is necessary to "poll" a PLC, to get updates on its values, in a Python program. We can't have the PLC spontaneously send its updated values to the Python 'cpppo' program using "Connected" messages.
Hope that helps!
I'm sorry I don't really have an issue, but I don't see a forum for asking questions about cpppo other than here. If there is one, please feel free to point me to more appropriate place.
I want to implement an Ethernet/IP server for a device and wondering if this is the best way to go about it with cpppo.
Thank you for any suggestions.