Host Engineering Forum
General Category => Do-more CPUs and Do-more Designer Software => Topic started by: brucek on July 09, 2020, 08:07:09 AM
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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.
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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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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.