Operation Steps

Required Steps

Step	Action
1	Configure Control Expert application and OFS.
2	Create the `##TSEventsGroup##`. Set this group to inactive.
3	Optional step described in the next topic.
4	Add the time stamped variables in the group (for example `myAlias!eventVar1`) as an active OPC item.
5	Activate the `##TSEventsGroup##`.

NOTE: When activating the ##TSEventsGroup## , OFS starts polling all event sources configured for myAlias. On group deactivation or removal, the polling is stopped.

NOTE: When an event value is notified to an inactive item, that event value is lost. Adding inactive items to the active ##TSEventsGroup## is not recommended.

Optional Steps

On OPC client initial start, it may be needed to initialize the cache values of the SOE viewer or alarm system with current process values.

To force the event source to provide current process values, proceed with the following steps during configuration (described in previous topic):

Step	Action
3.1	Create a new OPC group.
3.2	Add `#TSEventSynchro` variable to that group.
3.3	Perform a synchronous write on `#TSEventSynchro` variable ^(1.).
1. The return code of the OPC write operation is always `S_OK`; it means that the synchro value order has been taken into account by OFS. OFS manages the fact of sending this order to each time stamping module.

For more details, refer to topic Specific Item in OPC Factory Server User Manual.