Data sources provide the j5 Event Manager with operational tag information, such as the temperature of a reactor or the level of a tank. The j5 Event Manager then monitors this tag information, and raises attention when they exceed limits.
A tag is a unique name or identifier that identifies a specific data reading from a data source. A tag can be linked to a specific measurement tool on a piece of equipment.
For example, a data source tag linked to a thermometer reading on engine 1, can be named TEMP001. j5 can query (or "poll") the data source for the latest value of tag TEMP001. If the tag exists, the data source sends the latest value for the tag to j5. j5 saves this value in the j5 database, which the j5 Event Manager monitors.
j5 can retrieve tag information from a range of different data sources. The data sources are typically plant historians like Wonderware, PI, and IP.21, and various Distributed Control Systems (DCS).