Ok, I've hit a road block on this project. I still want to use UDP (I'm interfacing with a 3rd party vendor and they are using UDP broadcasts), but I can't seem to get the CP443 to receive data. Here is how it's set up:
1) I'm using a 443-1EX11-0XE0 V2.3, hardware release 4
2) In the connection table, I am using an unspecified UDP connection.
3) I am currently using port 4100, but I've tried 17000 also.
4) Currently, I am not defining a partner address ("Address assignment in block" is checked). I will be receiving from a Microsoft app, and MS assigns the port when the app launches, so it would be pointless to hardcode a port. Besides, I will be listening only, not broadcasting. If I have to broadcast for some reason, I'll enter the partner IP and Port programatically.
5) I am using FC60 (AG_LRECEIVE).
I am using a network sniffer to analyze the UDP packets, and they look ok. I set up the sniffer to send packets from my PC to the PLC once per second, and those packets are successfully broadcast. If I look at the data light on the CP, it flickers with each broadcast. If I look at the network statistics on the NCM S7 Diagnostics, the received messages increments as you would expect.
But, if I look at the UDP statistics within the same diagnostics, the received value remains at zero. All I can think of is that there is something wrong with the packets that makes Siemens refuse them (I found a note somewhere that mentioned that Siemens will filter the messages to prevent the stack from overflowing).
So, has anyone here received UDP packets successfully before using a UDP Unspecified connection? Should I be using a different connection type to receive these packets?