A/B DH+ Comms problems

bks

Member
Join Date
Aug 2003
Posts
4
A/B 500-4 plc with DH+ comms comms lockup on plc if you remove DH+ plug from cpu DH+ LED remans on the only way to reinste the comms to power down plc I have check all the message blocks registarys over laps

can eny one help
 
That symptom sounds like the DH+ outgoing MSG buffer is full. How many MSG instructions are there in your program ? The SLC-5/04 can process four messages simultaneously, then there is a buffer that will hold ten more (they get the ".EW", Enabled and Waiting, bit set). If you overflow that buffer, though, the port gets jammed up and you need to cycle power to reset it.

In encourage you to proofread your next post. Your sloppy grammar discourages people from assisting you.
 
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