Read UDP datagram from multicast group

PLCnext Technology & PLCnext Controls
1

Hello, I’m trying to read an UDP datagram from device that publishes on a multicast group (IP 239.12.255.254 and port 9522). I’m using UDP_SOCKET & UDP_RECEIVE but I couldn’t read. I tried some tests by changing UDP_SOCKET function block configuration: 1) BIND_IP: 239.12.255.254 / BIND_PORT: 9522 status response: 0xC205 | Only one use of an address is normally permitted.

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2) BIND_IP: 0.0.0.0 / BIND_PORT: 9522 status response: 0xC205 Only one use of an address is normally permitted.
3) BIND_IP: 10.110.50.194 (Fixed device ip. Same range as PLC) / BIND_PORT: 9522 status response: 0xC206 The selected IP address is not valid in this context.
4) BIND_IP: 10.110.50.197 (Fixed PLC ip) / BIND_PORT: 9522 status response: 0xC205 Only one use of an address is normally permitted.

Any help? Is this kind of communication possible? Thanks!

2

Hello,

unfortunatly the IEC 61131 FBs and eCLR-C# currently do not support UDP multicasts.

We have this issue recorded as a requirement and hope to provide this functionality asap.

Probably with FW > 2021.3 this functionality will be added.

kind regards,
Oliver

3

Hello I made some tests recently with FW and PlcNext version 2020.6. On the AXC F 2152, I could receive an UDP broacast message. Does this mean that the issue has already been fixed, and if yes, in which version was it fixed, or did I make a misunderstanding of the issue? In my case, i made a Send to a roadcast adress : a.b.c.255. Is it the same behaviour that the issued which describes Multicast issue?

4

Hello Michel,

thanks for the hint.
No it has not been fixed in 2020.6
Broadcast is not the issue but multicasts.

We hope to add this feature by FW 2021.3 or 2021.6