Hello all,

I am new to PLC programming. I am programming an S7-1500 to receive UDP messages from a PC to perform certain operations upon receiving the packet. To do this, I am going to use the TRCV_C block, but I am not sure how to configure it properly. The block will be receiving a string from a desktop program I wrote in C# using a UDP socket. The program does work, as I have tested it between two PCs but I cannot seem to receive the packets with the PLC. I have searched around online but the resources I have found haven't helped me much since I am new to this. Any help is greatly appreciated.

Thanks,

Ian

There is much failure prior to success with this.

Look at the documentation very carefully and be sure and set values as required for the UDP to work.

If you search, you may find an example application that does most of the work for you. 

i_was

Hello all,

I am new to PLC programming. I am programming an S7-1500 to receive UDP messages from a PC to perform certain operations upon receiving the packet. To do this, I am going to use the TRCV_C block, but I am not sure how to configure it properly. The block will be receiving a string from a desktop program I wrote in C# using a UDP socket. The program does work, as I have tested it between two PCs but I cannot seem to receive the packets with the PLC. I have searched around online but the resources I have found haven't helped me much since I am new to this. Any help is greatly appreciated.

Thanks,

Ian

Hello i_was

In this Example you should find the configuration on S71500:

https://support.industry.siemens.com/cs/ww/en/view/58875807

Its not exactly your usecase but I hope it helps.

ByeMurof

Do I need to use the TCON block? It was my understanding that the connection can be configured completely by TRCV_C and I would not need TCON. 

Thanks,

Ian

I would like to add that once the connection is made, I would like it to remain open forever, ready to receive the packets from the PC application, without the connection ever being closed.

Regards,

Ian

I was able to get the communication to work. It turns out that I had not quite configured the TRCV_C block parameters completely correct. I used the example program included in Murof's link and looked closely at how the block parameters were associated to specific tags and made sure that the expected data types were in order. One helpful trick was making the received data area into a Byte Array (my program technically changes the string to be sent into a byte before sending it through the socket) just like the example and properly configuring the IP address and port number very similar to the example program. Thank you guys for your help. I'll mark as solved.

Regards,

Ian