Detecting a down Ethernet link

[Henryp]

With a Do more CPU if the internal Ethernet link goes down can the CPU detect it? How about with an Ecom 100 in the rack?

[BobO]

Never thought to do that actually. No, there is currently no way to monitor link status from within the CPU unless the port is being used for something like Ethernet I/O, in which case it would start ringing up errors. Theoretically it would be possible to make the hardware do it, although I'm not sure whether it would take firmware alone or also gate array.

[ATU]

What is the device on the other end?

[Henryp]

It is a DL PLC. I want to use the Domore as a frontend data collector. When we were testing I had the port unplugged and didn't realize it

[ATU]

Would a heartbeat technique help? 

[CReese]

As I was just instructed, use the PING instruction with a host that you know will always be on. Could use a router or the closest node on your network.