I/O Modules - BACnet - Change of Value

The article outlines which input types in multiprotocol I/O modules contain a ‘Change of Value’ subscription in the BACnet network.

• ‘Digital Input’ - All ‘Binary Input’ type objects have the ‘COV’ function; the subscription is started with each value change. If the DI input is configured as ‘Counter Input’, the ‘Change of Value’ subscription is not available for objects representing meters, that is ‘Acumulator’ and ‘Analog Value’.

• ‘Universal Input’ - ‘Analog Input’ type objects allow the ‘COV’ subscription. Also, these object has the ‘COV INCREMENT’ functionality, which allows to configure the ‘COV’ subscription sensitivity. If the universal input is configured as a digital input ('Binary Input'), the 'COV' subscription is available with each input value change.

• ‘Digital Output’ - All ‘Binary Output’ type objects have the ‘COV’ function; the subscription is started with each value change.

• ‘Analog Output’ - ‘Analog Output’ type objects allow the ‘COV’ subscription. Also, these object has the ‘COV INCREMENT’ functionality, which allows to configure the ‘COV’ subscription sensitivity.