Source Timestamped Events Support

Source Timestamped (TS) Event Group Support

Time stamped functionality is currently implemented and supported only for digital events. For configuration details refer to TS Quality Support.

The driver creates a new OPC group to manage all OPC items with TS Event support. There is only one TS Event OPC group created per driver instance.

The driver creates and activates an OPC group called ##TSEventsGroup## at start up and deactivates and removes that group at shutdown.

After the TS Event OPC group has been created, the driver periodically (every 500ms) signals that it is active by writing to the <<system>>! #ClientAlive OPC item.

As start up the driver reads the TS Event Support item property (Id: 5012) and adds those items which support TS Events to the TS Event Group.

After TS Event items have been added and activated the driver writes to the #TSEventSynchro item to get the current values of all TS Event items.

Plant SCADA Configuration for Source TS Support - Ports and I/O Devices

There must be only one logical device and one port configured to communicate with all available TS Sources. This is to ensure the following

• Single client connection to OFS

• Driver issues only a single request to OFS for initial data from all available TS sources.

Accordingly, only one primary IO Device/Port and one Standby IO Device/Port can exist in the project in the case of redundancy.

Compatibility

The driver initializes TS Event support only if the following conditions are true:

• Plant SCADA v7.20 or higher version is used.

• OFS Server v3.40 or higher version is used.

• EventServiceSupport setting in DeviceConfig.xml is set to True for a specific device alias.

Note: When the source event buffer in the PLC is full, any new events will not be stored. In this case the value of SOE_Uncertain variable becomes TRUE. When the buffer becomes available again, the PLC will provide the values of all time-stamped event variables. As these values are timestamped with a current time, the time quality of these values will be set to Invalid. The SOE_Uncertain is a variable in a time stamped event source whose value becomes TRUE when there is no space in the event buffer.