Communication Protocol; Contents Of This Chapter; Bacnet/Ip; Prioritizing Commands - ABB FBIP-21 BACnet/IP User Manual

Communication protocol 39

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Communication protocol

Contents of this chapter

This chapter describes the BACnet/IP communication protocol for the adapter module.

BACnet/IP

BACnet/IP is a standard data communication protocol intended for supervision and
control of building automation equipment. The FBIP-21 adapter module supports the
BACnet protocol version 1, revision 14 according to the ISO 16484-5:2014 standard.
BACnet/IP uses objects to abstract and represent information. An object is a collection
of data elements called properties. The type of the object determines which properties
are present. This information is accessed through standardized services, which can
also be used to command BACnet devices.
The FBIP-21 adapter module acts as a server providing object data access for BACnet
clients.

Prioritizing commands

Commandable objects consist of priority array property, which is used to store the
command priority. If you do not define priority with a command (example, write service
request), the priority defaults to the least important command.
If the client no longer needs to control an object, it can relinquish the control by writing
the priority property value as NULL. For more details, see the BACnet ISO standard
16484-5:2014.
Note: Priority arrays are not stored over the power cycle.