Data and Event Integrity

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Data and Event Integrity

An integrity command performs a request of all data configured in a Slave, for all Class 0 (zero) objects or for specific objects.

Due to a peculiarity of DNP protocol sending together with integrity the current value of variables, therefore as static objects and not as events, this Driver must process this information to unify the static value with the event's value, so that an application has a single Tag for the point.

This way, if the application uses Tags as events, as recommended in this document, then during start up, when receiving an integrity (Class 0) with a point's static value, a temporary event is generated with its Quality property equal to 216, indicating that the timestamp used was not generated by the device, but rather by the computer's local time, due to the lack of this information in the integrity.

As soon as there is a reception of an event for this Tag, then its quality changes to 192 and its Timestamp property reflects the timestamp received from the event, if the object contains one.

 

NOTE

Quality values mentioned previously assume that object statuses are informing a normal situation, otherwise quality values reflect a point's bad status, as described on topic Quality Information.

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