According to the BACnet protocol documentation:

Indicates the date and time when a reference to an Access Credential object has last been added to the Credentials_In_Zone property. If this property is present, but no credential has yet been added, then this property shall not convey an actual time and shall contain a value of X'FF' in all octets.

Property lastCredentialAddedTime of object accessZone can be read and written using a single IOTag.

Text Parameters

Numeric Parameters

Tag Value

A Date, Null or String (Xml) value representing a BACnet date/time.

•A null value means the date/time is empty/not set;

•A date/time value representing a precise date and time;

•A character string containing an XML with a value of type <BACnetDateTime>.