Siemens communication fault

We have been recieving an alarm on one of our HMIs saying "No S7 communication peer found." It happens at random times.. could be while the production line is running, or while it is stopped. I have checked all connections, and I do not believe it to be heat related or anything. Any ideas? Also, are slave modules considered peers? Or would just the master PLC and the HMI be peers??

By the way, I am fairly new to this and I promise as soon as I get good at it I will help all of you as much as possible. Thanks

Hi jmc

Welcome first of All.

Now I would not be the best here to help you with s7 but many here will.
But to get the best help here you will need to add more detail. Like the CPU type, the HMi type and part number, what comms is used.Is this new, has it been running for a long time and if so has there been any mods lately.
The more information you give the better answer you will get back.

Donnchadh