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Author Topic: Ethernet Comms loss question?  (Read 6789 times)

brucek

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Ethernet Comms loss question?
« on: July 09, 2020, 08:07:09 AM »
I have 2 BRX plc's communicating over peer link. I use 1 as the master so to speak and the other is used as a remote base but i need high speed cards in both locations so I'm using the 2nd plc as a remote rack. The "remote" controls 2 motors and I'm wondering if something happens that I lose comms with the master will the motors stay on since they won't get the signal to shut down when the "master" says to turn off.

Is there a ST or DST for Ethernet comms ok? Or should i do something like turn on/off  a bit ( every second) send it thru peer link and have it reset a timer in the "remote" base lets say 5 second timer and use the done bit to turn off the motors?

I looked thru the list in help and see there is some packet loss stuff but don't think that is what I'm looking for.

BobO

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Re: Ethernet Comms loss question?
« Reply #1 on: July 09, 2020, 09:24:52 AM »
I have 2 BRX plc's communicating over peer link. I use 1 as the master so to speak and the other is used as a remote base but i need high speed cards in both locations so I'm using the 2nd plc as a remote rack. The "remote" controls 2 motors and I'm wondering if something happens that I lose comms with the master will the motors stay on since they won't get the signal to shut down when the "master" says to turn off.

Is there a ST or DST for Ethernet comms ok? Or should i do something like turn on/off  a bit ( every second) send it thru peer link and have it reset a timer in the "remote" base lets say 5 second timer and use the done bit to turn off the motors?

I looked thru the list in help and see there is some packet loss stuff but don't think that is what I'm looking for.

PEERLINK is a just a broadcast, so we can't really know that anyone on the other end received it. If you need to know for certain, consider something like DLRX/DLWX. If you choose to stay with PEERLINK, then yes, some form of heartbeat would be prudent.
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ATU

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Re: Ethernet Comms loss question?
« Reply #2 on: July 09, 2020, 02:37:10 PM »
I sometimes use an incrementing register being read by the receiving device. If I don't see the data change to the next number then I know things went south.