Slow communication PC > ControlLogix


Thread Starter

a brown

The ControlLogix PLC is fairly new install. We have no trouble with it (obvious problems) communicating with other PLC's it sends/receives packets from, but we have a lot of trouble with it communicating with our PC. We use RSLogix5000, we also use same DH+ to communicate with 10 other PLCS (all PLC-5) with no problems. Only the ControlLogix has a severe time lag and makes it difficult to troubleshoot problems. BTW- we have a KT card in PC that we communicate on the DH with (daisy-chained)

Question is Is there something not set correctly in RSLinx for the COntrolLogix?

The DH+ cards for control logix have an undersized buffer for larger applications. I'm not sure what buffer :-/, but the paper mill I worked for previously used multiple DH+ cards to break up the network. The old PLC-5 stuff worked great without this work around. This might be your problem

Maybe you need to check system overhead timeslice at RSLogix 5000
(Controller Properties - Advance), try to increase the system overhead