OPC connection gets disturbed frequently
I am using 800M redundant controllers with Compact HMI V5.0. Very frequently i observe cross marks in the display area. At times when i enter the set point in the faceplate , the cross mark disappears. But most the times i have to close the workplace and re-start the system. This kind of activity is observed 3 to 4 times in a day. OPC files have not been disturbed too. Kindly help on this issue.
Thanks in advance.
Have you checked the Diagnostic Window in Process Graphics (right click) for indications of bad quality from OPC DA?
Bad quality is usually an indication of a saturated MMS communication, communication disturbance between the AC800 OPC server and the controller or CPU overload in the AC800M CPU.
How many transactions per second are the controllers handling (CBM->Remote System->IP address->Show MMS Connections)?
How high is the Total System and Cyclic Load in the controllers?
I suggest that you contact your regional ABB support center and ask for assistance.
Basically, it sounds like clicking on a faceplate or entering data is probably refreshing a broken OPC subscription.
There are MANY possible causes for this, but the most likely is that you are loosing network connectivity between your computers.
However, you do not give enough information for anyone to solve your problem. You really need to search for more error messages, including in all of the Windows error logs on all computers, the RNRP diagnostics and the Compact HMI System Diagnostics logs. You need to describe if the problem happens on one client, all clients, the server etc. does it happen at specific times of the day, when did it start, have you changed any hardware etc etc. information like this will help you to isolate potential causes.