Unsolicited Response settings
DNP3 is an event-driven protocol. Instead of the master continuously polling the slaves for changes, the slaves monitor any data changes, such as bits toggling and analog value changing outside of a deadband. They then report the updates to the master as timestamped events in one of the following ways:
- Unsolicited response: Sends the updates as a write message initiated by the slave.
- In response to the poll from the master: Data objects in the slave are configured to Class 1, Class 2, and Class 3, typically based on priority. The class of the highest priority is polled more often.
Setting | Description |
---|---|
Channel for unsolicited response | Determines the communication channel over which unsolicited responses are sent.
Only channels that are configured for DNP3 protocol are available in the list. Options are:
|
Restore events after a power cycle | Determines whether to restore the event records after a power cycle. By default, the controller deletes any DNP3 event records in the memory when power is cycled. |
Send the initial unsolicited null response on restart | Determines whether the controller sends the unsolicited null response with the RESTART IIN bit on startup. |
Enable unsolicited response on startup | Determines the way that the controller sends the unsolicited response.
|
Number of retries | Specifies the number of message resend attempts. Options are:
For unsolicited response only. |
Unsolicited response for Class 1 | Turns unsolicited response for Class 1 on or off. By default, it is turned off. |
Unsolicited response for Class 2 | Turns unsolicited response for Class 2 on or off. By default, it is turned off. |
Unsolicited response for Class 3 | Turns unsolicited response for Class 3 on or off. By default, it is turned off. |
Number of events | Specifies:
|
Hold time after events | Specifies the maximum duration, in seconds, for a group of events to be held before sending an unsolicited response. The box is available when unsolicited response for the class is turned on. The value is from 0 through 65535. |
Provide Feedback