AC500 CPU goes to full load while communication is established with Cimplicity SCADA.
1) I have the downloaded my program in PM 573 PLC. I checked the CPU load in PLC Browser window. It shows 46%.
2) I start to run my Cimplicity SCADA. Tags are browsed via Modbus TCP/IP. Now i check my cpu load. It says 100%.
Since it shows 100% , at times the operation of my machine gets hanged. No Ouputs are energised as per sequence.
Does communication ports of AC 500 PLC count into load calculation of CPU? If so, on what basis. Because AC500 has 3 communication ports in its base by default. Kindly help me with a solution .
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In my experience with the AC500, external communication requests will add the the load of the CPU, I have even seen cycle time lag by just doing online monitoring. This happens most frequently when I connect a PLC to our office network which has alot of unmanaged traffic.
You can use a program like WIRESHARK( www.wireshark.org) that will let you capture snapshots of the traffic to and from your PLC, and make sure it is not being overloaded with requests.