Detection of communication loss between dPac's

[BenoitDery]

Hi experts,

What is the best practice to detect a communication loss between dPac's?

Example:

A DIG_IN mapped to a TM251dPac is linked the run command of a ATVdPac. When the Ethernet communication is lost I want the ATV to stop for security reasons.

Of course, I can use a time based trigger like E_CYCLE to check this, but I suppose there must be a better way.

Any suggestion would be much appreciated!

[Richard · Accepted solution]

Obviously here is no point checking just once, so E_CYCLE in the M251 dPAC is a good way to perform the check as this will trigger regular events to do the checking. Inside the ATV dPAC you can use something like E_DELAYR to check the received pulses - use the pulses to reset the delay timer. This way if the pulses stop, the delay timer will time out and can then trigger the logic to to stop the motor.

There are other ways but this is probable the simplest.

[BenoitDery]

Thank you Richard! I guess I was hoping for a kind of automatic communication check. This was a question raised by a customer during a demo. I didn't include any communication check at the time, so the ATV fitted with ATV dPac stayed in its last state (running or not) when disconnection the network. This behaviour is of course something very important to be aware of.