Time Stamp of simple event
Months ago I've asked here these two questions:
But the project was paused and now I'm returning it.
I have the following doubt:
How do I make the time stamp from an already configured DA point equal to cpu and not the system machine? Do I really need the simpleevent block for each point?
Am I in the correct direction with these questions above?
You must keep the OPC DA and AE protocols separated (they work independently).
OPC DA data is timestamped by the computer clock in the AC800M OPC server node.
OPC AE data (simple events and condition events) are time stamped by the AC800M CPU. Some IO modules, e.g. DI830 support SOE which enhances the quality of the OPC AE timestamps by performing the timestamping on the IO module itself rather than in the AC800M CPU.
To keep DA and AE data as synchronized as possible you should configure a clock sync protocol between the AC800M and the AC800 OPC Server. This is described in the Automation System Network Configuration User's Guide, there are two protocols available: CNCP and SNTP. Correctly configured time synchronization accuracy should be down to milliseconds (even better between AC800 and another AC800).
The Control Builder M's OnLine Help contains further information (e.g. how to configure SOE).
However, since AE is purely event driven and DA is a polling protocol a DA timestamp of a triggered signal may differ up to a second or more with an AE simple event based on the very same signal because the fastest DA polling interval between OPC server and controller is 500 ms (default OPC item update rate is 1000 ms) and accuracy will drop with increasing communication and controller CPU load.