IDEC MICRO/I HG1P-ST32 Series

WindO/I-NV4 User’s Manual 3-103
7 BACnet Communication
3
Communication
● Foreign device function
When the BACnet/IP network is built with multiple IP subnets, install one BBMD (BACnet Broadcast Management
Device) on each IP subnet. A BBMD is a device that transfers broadcast communications of BACnet devices to
different IP subnets. BACnet devices perform broadcast communications with BACnet devices on different IP subnets
via BBMDs. The Foreign Device function is used for performing broadcast communications with BACnet devices on
different IP subnets even when there is no BBMD on the IP subnet of the MICRO/I. Broadcast communications can be
performed with a BACnet device on the BACnet/IP network by registering the MICRO/I as a foreign device for a
specified BBMD.
BBMD
Bridge
Internet
IP subnet 1
BACnet/IP network
BBMD
Bridge
BACnet
device
BACnet
device
BACnet
device
BACnet
device
10.3.1.1
255.255.255.0
10.3.1.8
255.255.255.0
10.3.1.2
255.255.255.0
10.3.1.3
255.255.255.0
IP subnet 2
MICRO/I
Bridge
192.168.1.11
255.255.255.0
192.168.1.6
255.255.255.0
IP subnet 3