The following data will be reloaded on a trend server when adding, removing and modifying the records of:
Modifying the following archive properties will put a record in an error state and no acquisition will be done for corresponding records:
A hardware alarm, a syslog entry and a reload error message will be raised. The history files will not be deleted. For periodic to periodic Type changes, reload will not generate an error.
If you want to have a valid archive for the modified record, you need to delete the old history files (after archiving manually) and then trigger the reload again after forcibly compiling the Trend configuration. This is necessary because the trend system doesn’t reload the trend rdb file if the compile time of in-memory file is same to the on disk file. Therefore changes to an existing trend record’s archive properties is a two staged reload.
Due to reload the display clients will need to request the latest configuration data for trend records. The Process Analyst will periodically refresh configuration data from the trend server. The Trend server tag browsing is optimized to handle the more frequent requests.
For legacy trends including SPC, configuration data will be refreshed from the trend server when a page update is triggered.
See Also
Published June 2018