Understanding bacnet objects – Rockwell Automation 20-750-BNETIP BACnet/IP Option Module User Manual

Page 38

Advertising
background image

38

Rockwell Automation Publication 750COM-UM005B-EN-P - June 2014

Chapter 4 Using BACnet Services and Objects

The table below provides a brief description of these services.

Table 2 - BACnet Services Supported by the Option Module

Understanding BACnet

Objects

BACnet devices are controlled and monitored by the use of several objects. The
BACnet controller performs read and write services to these objects, and the
option module translates the data between these objects and the PowerFlex 750-
Series drive.

When a read or write service occurs to a specific object, data in that object is
refreshed from or transferred to the drive.

These are the BACnet

object

types supported by the option module:

• Analog Input (AI)
• Analog Output (AO)
• Analog Value (AV)
• Binary Input (BI)
• Binary Output (BO)
• Binary Value (BV)

Property Type

Name

Description

Object Access

Services

Read Property

Service

This service is used to read parameter values represented

by BACnet objects for the PowerFlex 750-Series drive or

option module.

Write Property

Service

This service is used to write values to parameters

represented by BACnet objects for the PowerFlex 750-

Series drive or option module.

Read Property

Multiple Service

This service is used to read multiple parameter values

represented by BACnet objects for the PowerFlex 750-

Series drive or option module.

Write Property

Multiple Service

This service is used to write values to multiple

parameters represented by BACnet objects for the

PowerFlex 750-Series drive or option module.

Remote Device

Management

Services

Who-Has and I-Have

Services

Who-Has service is a request to identify an object

specified by the object identifier or object name.
I-Have service is a response to respond to Who-Has

service requests.

Who-Is and I-Am

Services

Who-Is service is used to determine the device object

identifier, the network address, or both, for all BACnet

devices on the network.
I-Am service is used to respond to Who-Is service

requests. It is independent to Who-Is service and may be

issued at any time. It is also used to broadcast the

existence of the option module, or all BACnet devices on

the network.

Advertising