MVP 2021 Flex727 Posted August 28, 2012 MVP 2021 Report Share Posted August 28, 2012 I wonder if any wise programmers might have some helpful hints. I've been programming for awhile, but I'm still a bit sketchy about networking. When I have two v570 PLCs communicating with each other, it's important to know (and potentially correct automatically) when a communications error occurs. I'm attaching a subroutine example in the master PLC where I communicate with the slave and detect a comm error by looking for a change in the count of data received to the socket (SDW21, for Socket 3) - ladder rungs 5-7. Currently I initiate communication every 250ms and if I go for 2 sec without the RXD count increasing then I alarm. This seems to work well, but is there a better way? Also, when a comm error is detected, what is the best procedure for making an attempt to re-establish communication automatically? Thanks. By the way, I'm using VisiLogic 9.4.0, if it matters, and communicating by MODBUS IP over Ethernet. Quote Link to comment Share on other sites More sharing options...
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