Object and Property Identifiers

Object Identifiers

Every object in a BACnet device has an object identifier consisting of two parts, an object type and an instance number:

object-type,instance

The object-type is the enumeration name in the ANS.1 definition of the BACnetObjectType in Clause 21 such as binary-input, calendar, or device. The object type may also be an unsigned integer in the range 0..1023.

Note

Enumerated values 0-127 are reserved for definition by ASHRAE. Enumerated values 128-1023 may be used by others subject to the procedures and constraints described in Clause 23.

The instance is an unsigned integer in the range 0..4194303, note that 4194303 is reserved for “uninitialized.”

Caution

BACpypes3 also supports the legacy BACpypes format where the object type and instance are separated by a colon ‘:’ and the object type names are lower-camel-case such as binaryInput. This format is discouraged and may be deprecated in a future version of BACpypes3.

Property Identifiers

Every property of a BACnet object has a property identifier:

property-identifier

The property-identifier is the enumeration name in the ASN.1 definition of the BACnetPropertyIdentifier in Clause 21 such as object-name, description, or present-value. The property identifier may also be an unsigned integer in the range

Note

Enumerated values 0-511 and enumerated values 4194304 and up are reserved for definition by ASHRAE. Enumerated values 512-4194303 may be used by others subject to the procedures and constraints described in Clause 23.