Mitsubishi Electronics PAC-YG31CDA User Manual

4.Functional specification

4.1 Communication Protocol Specification

1) Protocol Outline

BACnet/IP which applied to ANSI/ASHRAE 135-1995, 135a, 135b correspondingly on UDP/IP

of Ethernet is used.

APDU of BACnet

NPCIof BACnetNETWORK

BVLL Header

UDP Header

IP Header

Ether Header

2) Ether Header

A physical layer sets a transmission medium to 10 BASET by Ethernet.

3) IP Header

The private address of Class C is recommended (*1). Subnet mask 255.255.255.0

*1: Recommendation value (range) [192.168.1.1]～[192.168.254.254]

[192.168.0.0] and [192.168.255.255] do not use it.

4) UDP Header

The default UDP port of a unicast and broadcasting is set to 47808 (OxBAC0).

5) BVLL Header

BVLC type (one octet)

0x81 fixation (BVLL to BACnet/IP)

BVLC function (one octet) 0x0A At the time of a unicast

0x0B At the time of broadcasting

BVLC length (two octets) Arbitrary (wording-of-a-telegram length setup: a big endian specification)

NPCI of BACnetNETWORK

Version (one octet)

0x01 Fixation

Control (one octet) 0x04 Those with a response message

0x00 With no response message

7) APDU of BACnet

It has arbitrary lengths of 1024 or less octets. Contents details are ANSI/ASHRAE135-1995, 135a, 135b

references.

8)Application of BACnet

・

The instance number of a Device object

3(Setting change of a instance number is possible)

・

Segmentation

Transmission

and

reception

are

un-supported.

・

APDU which can be received

1024 octet

・

APDU timeout

3 sec(Setting change of a instance number is possible)

・

Vender

ID 99

・

Process ID

blank (Setting change of a process ID is possible)