Address; Bacnet Profile; Readproperty (Ds-Rp-B); Writeproperty (Ds-Wp-B) - WEG bacnet CFW701 User Manual

2.2

ADDRESS

It presents an address range from 0 to 254, where:
The range from 0 to 127 is reserved for master or slave nodes;

The range from 128 to 254 is used only by slave nodes.

The broadcast telegram must have FFh (255) in the destination address field.
The serial address is set using parameter P0308 in the CFW701.
2.3

BACNET PROFILE

The BACnet profile developed for the CFW701 is the B-ASC, with communication management services and
data sharing that presents the following BIBBs (BACnet interoperability Building Blocks):
DATA SHARING:

DS-RP-B: ReadProperty;

DS-WP-B: WriteProperty.

DEVICE and NETWORK MGMT:

DM-DDB-B: WHO IS / I AM;

DM-RD-B: Device Management-Reinitialize Device-B.

2.3.1

ReadProperty (DS-RP-B)

A BACnet client (node performing a request to a server node) uses the ReadProperty service to obtain a BACnet
object property value. This service allows reading access to the properties that have the R (reading) access
type.
2.3.2

WriteProperty (DS-WP-B)

A BACnet client uses the WriteProperty service to modify the value of a specific BACnet object property. This
service allows writing access to the properties that have the W (write) or C (commandable) access type.
2.3.3

WHO IS / I AM (DM-DDB-B)

The WHO IS / I AM service is used to identify the devices connected to the network. The WHO IS message is
sent by the BACnet controller, and the nodes respond with an I AM message, informing their Object Identifier
and address. The I AM message is transmitted in broadcast, and can be transmitted during initialization or
continuous, according to the parameter P0764.
2.3.4

Device Management-Reinitialize Device-B (DM-RD-B)

The Reinitialize Device service is used to remotely reinitialize the equipment, and uses a password to validate the
service execution. The BACnet standard defines that the password is a string (set of ASCII characters) with up
to 20 positions. The password used for the CFW701 remote reinitialization is the same one used to allow the
access for parameter content modifications, informed in the parameter P0000. This password can be a number
between 0000 and 9999.
The BACnet password for the CFW701 is a 4-character string. Therefore, the BACnet password can be a
number between 0000 and 9999. E.g., considering that the CFW701 default password is 5, the remote
reinitialization service will only be executed if the received password is "0005".
Introduction to the BACnet Communication
CFW701 | 10