since you are online, can you help me on these question.
what is the danger of if total load is more than 100%.
at the same time cyclic load only 40%.
can this scenario happen.
hope you able to help me
do you want my email?
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1. Check module bus scanning time; do not use 0 (as fast as possible)
2. Check communication budget (CBM->Remote System->Show MMS Connections).
Check what is communicating with your PLC; try to reduce the amount of communications, e.g. less OPC items subscribed from the OPC server or less frequent MMS read/write between controllers or process panels.
The "Cyclic Load" is the load of your control software. It includes the task times of the PLC programs and also AFAIK scanning of modulebus. ( Stefan can confirm this, I may be wrong, we never use module bus for more than a few signals)
The CPU will not allow this to run above 70%. If it the cyclic load rises then the task intervals are increased. If they increase too much then latency supervision will kick in and shut the controller.
The "communications load" on a controller should be roughly constant and be somewhere between 20% and 40%. Typically this value should be 30% or less, but seems to be higher on batch systems or systems that use a lot of strings.
The total load is the Cyclic Load plus the communications load.
If you have a cyclic load of 40% but a total load of 100%, then something is wrong. Communications load should not be above 40% and should normally be less than 30%.
If you have a cyclic load of 40% and a total load of 70% then every thing is fine.
You MAY see the controller load increase when a new program is downloaded. A warm start causes all of the "Start_" code to be executed which can increase the CPU quite a lot for the first program scan. Again, this will not exceed 70%, If the total load runs at 100% for a few seconds this is quite normal - but if there is a real problem then the latency supervision might kick in.