Some DNP3 outstations have the capability to report event data to the DNP3 master (for instance ClearSCADA) independently of that master’s polling cycles. The outstations report such event data to the master by transmitting unsolicited messages.
Use the Enable Unsolicited Messages section on the DNP3 Outstation Form to specify:
- Whether an outstation is allowed to transmit unsolicited messages
- The data classes for which it is able to transmit such messages.
For more information, see Enable Unsolicited Message Generation.
In addition to the above, Enable Unsolicited Events and Disable Unsolicited Events pick actions can be used to enable or disable unsolicited events on an outstation, as required.
If the outstations use DNP3 Secure Authentication:
- On systems on which ClearSCADA is the DNP3 master, use the Unsolicited Response check box in the DNP3 Master section of the ClearSCADA Server Configuration Tool to specify whether unsolicited messages are challenged.
- On systems on which ClearSCADA operates as a DNP3 slave, use the Unsolicited Response check box in the DNP3 Slave section of the ClearSCADA Server Configuration Tool to specify whether ClearSCADA sends unsolicited messages using Aggressive Mode.
For more information on either section of the ClearSCADA Server Configuration Tool, see Define Which Function Codes are Critical.
You can use the Unsolicited Event Reporting Status attribute to ascertain which unsolicited event classes are enabled and disabled in an outstation.