Issue
Instead of logging a value on a set time interval, can I only log the value when it changes?
Product Line
Andover Continuum
Environment
- Logging - all controller types.
- Time Interval = 0
- Log value on change.
- Semi Automatic logging.
Cause
When working with strings, date times or Plain English comms drivers, it is often required to only log a value on change. How can this be achieved?
Resolution
- Create the point in the usual way.
- On the "Logs" tab, enter the number of log entries required.
- Select "Log Instantaneous."
- Leave all of the Time intervals at 0.
The controller will now log a new value every time the point value changes and all log entries move down 1 position. This is often called Semi Automatic logging.
Note: This logging method is not related to time in any way, however creating an Infinity DateTime point and writing to that with the Date system variable when the point is updated would allow the time / date of the change to be recorded.
