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3.1
Basic Functions
BAC-HD150 has functions that communication from an air conditioning system is protocol converted to BACnet
®
communication, that command from a Building Management System is converted and transmitted to an air conditioning
system, and that air conditioning system status data is collected and the status change is detected. BAC-HD150 also collects
data on air conditioning units operation status and transmits the data upon request from the building management system.
Refer to “3.4 Relations between objects and control items” for control item of BAC-HD150.
3.2
Communication protocol specifications
(1) General descriptions of protocol
BACnet
®
/IP which applied to ANSI/ASHRAE 135-2004 correspondingly on UDP/IP of Ethernet is used.
Ethernet is a registered trademark of Fuji Xerox, Inc.
(2) Ethernet header
Physical layer: Ethernet
Transmission medium: 10BASE-T
(3) IP header
Class C private address is recommended. (*1) Subnet Mask: 255.255.255.0
*1: Recommended value (range): [192.168.1.1] - [192.168.254.254]
Do not use [192.168.0.0] and [192.168.255.255] as a device address.
(4) UDP header
The default UDP port of unicast and broadcasting is set to 47808 (0xBAC0).
(5) BVLL header (BVLL: BACnet
®
Virtual Link Layer)
BVLC type
(1 octet)
Fixed to 0x81 (BVLL against BACnet
®
/IP)
BVLC function (1 octet)
Unicast 0x0A
Broadcast 0x0B
BVLC length (2 octets)
Variable (BVLL header (4 octets) + NPCI data APDU data length)
(Typical examples are listed above. Refer to ANSI/ASHRAE 135-2004 for details.)
(6) NPCI (NPCI: Network Layer Protocol Control Information)
Version (1 octet)
Fixed to 0x01
Control (1 octet)
Response is received. 0x04
No response 0x00
(Typical examples are listed above. Refer to ANSI/ASHRAE 135-2004 for details.)
(7) APDU (APDU: Application Layer Protocol Data Unit)
Data: 1024 octets or less
(Refer to ANSI/ASHRAE 135-2004 for details.)
3 Function specifications
Ethernet header
IP header
UDP header
BVLL header
NPCI
APDU
WT05542X04.book Page 9 Wednesday, July 3, 2013 12:13 PM
