IEC 60870-5-101 Protocol - Session question


Thread Starter


Hello, I'm trying to send a command ASDU to a PLC. However, I encountered a few difficulties. I tried to send a command ASDU to a PLC and the PLC ignored my command. I know for sure that the link ID that I sent is correct. I suspect that this is because that I didn't perform some sort of initialization or conversation hand-shake.

I couldn't find any explanation in the IEC 60870-5-101 standard regarding session management or conversation flow in the protocol. I will appreciate if someone can please explain me how to protocol works in this aspect.

Thank you very much,
Hi Noam ,

Could you pls mention more details. What about other requests and responses? whether they are working or not. What is the type Id of command you send? Which is the master you are using ?(which SCADA or Simulator)

In order to address a IEC101 device in a network,you have to know two addresses Link Address and Asdu Address. Also the link Address size in both master and slave side should be matching.

Thanks and Regards