Error in MMS communication in online system with PM851
I use PM851 and Control Builder 6.0.
I've already done some online changes without problems, but when I now go online and check the status of an IO slave with CI830 and AI801 I get the text error in MMS communication in online system in AI picture.
When I go into the application and checks the value of the AI, the AI value is OK.
I can no longer load new changes because I then get up error on fast task.
System load is as much as 81%. Cyclic load is 39% and used memory is 72%.
Values read from the OPS server to the scade system is also OK.
Is the problem only that the CPU is too small, will change this later to PM861.
The system guide recommends somewhere between 20-50% spare memory. It depends on the complexity of your application. Less memory is needed when you use more than one application (assuming they are smaller, then one large i.e. less spare-memory in use when downloading changes).
Cyclic load isn't the problem, the rest (system load) has to be communication. Check the settings for your coms and evaluate if you can "slow things down"?
Observe, if using serial protocols (CI or CN3), flushing those com-buffers when downloading (to secure not to loose info), may cause downloading take too long time and cause problems with fast tasks and/or CI-slave communication watchdogs... (i.e AC-Drive settings has to be changed)
In case you want, you can skip task analyzis prior downloading:
from Control Builder -> Tools -> Setup -> Station -> Application Download-> Enable TAskAnalyzis Tool = false.
You can try to optimize tasks by decreasing of execution time, offset e.t.c. PM851 is the smallest CPU, but memory of it is equal to PM856. PM861 is a bigger one.
I'm not quite sure, not understand your description of MMS communication error.