Issue
How will SQL logging be affected if a trend log's parameters are changed?
Environment
Vista 5.1.X
Cause
A customer may wish to log values from another point, eg if an energy meter has been changed, or may wish to change the frequency with which the point is logged.
Resolution
The simplest answer to this question is that if a change affects the log, the message "Log database will be emptied" will be displayed giving the user the opportunity to cancel the action. Depending on the type of trend log being used, the check box "Keep trend log values when changing log point" can be checked and this will allow the log point to be changed - all other parameters must remain the same.
It is not possible to change the log interval without emptying the log database for the point as a number of calculations are carried out when displaying log data in a client, that require the points to be logged at a regular interval.
