The DNP3 protocol uses object flags to indicate the status of a particular point value, for example, the 'Local Forced' object flag indicates that a value was overridden locally at the Field Device. With the WITS driver, you can configure your Field Device to perform a specified action when each flag changes (on each point):
- Take no action (None).
- Log an event that is stored in the WITS data log (Log Event).
- Generate a DNP3 event that is added to the event queue (Event).
- Generate a DNP3 event that causes the Field Device to open a connection to ClearSCADA (Alarm).
You can configure the following types of DNP3 Object Flags:
- Chatter Filter (Binary Input and Double-bit Binary Input points only)
- Comms Lost
- Discontinuity (Counter points only)
- Local Forced
- Online
-
Over Range (Analog points only).
- Reference Error (Analog points only)
- Remote Forced
- Restart
For details on the meaning of each object flag, see DNP3 Driver-Specific <Update Type> Status Values in the ClearSCADA Guide to the DNP3 Driver.
To specify the action that is to be taken when each DNP3 Object Flag changes, use the action setting in the DNP3 Object Flag Actions section (of the WITS Point Form). For more details, see Severity Types and Actions for WITS Database Points. The only exception to this rule is the Over Range DNP3 Object Flag which is separate to the other DNP3 Object Flags. The highest of the the 'zero scale' and 'full scale' severity types in the Alarm Limits section of the Form is used to define the action for the Over Range DNP3 Object Flag.