BBMD Help

The BACnet discovery process uses broadcast messages, but broadcasts are blocked by an IP router. To deal with subnets, a BACnet/IP Broadcast Management Device (BBMD) must be used. The BBMD functionality within the EIPR can be enabled from this page. It is disabled by default. You also need to configure the basic BACnet/IP settings on this page to enable BACnet communication through the EIPR.

The EIPR combines IP routing and BBMD. When the EIPR has the firewall enabled your system will need to use two UDP ports in order to traverse the EIPR. The WAN port will utilize one UDP port, for example BACO and the LAN port will utilize another, for example BAC1. The devices on the WAN port will need to utilize the EIPR's WAN UDP port setting and devices on the LAN port will need to use the EIPR's LAN UDP port setting. The port forwarding required to make this work will be automatically configured for you. If the firewall is disabled then there is no port forwarding and WAN and LAN BACnet devices will all utilize the same UDP port setting.


BBMD: You can enable or disable the BBMD functionality.

Accept FDR: You can enable or disable Foreign Device Registrations to the EIPR.


Device Parameters

Device Name (Default Value = EIPR-BBMD-xxxxxx): This is used to configure a unique device object name for the device on the network. It can be up to 80 characters and defaults to a unique name of the form EIPR-BBMD-XXXXXX - where the Xs are replaced with the final six characters of the EIPR's Ethernet MAC address.

Device Instance (Default Value = 0): The router's device instance is a 22-bit value (0-4,194,302). Do not use 4,194,303 which is reserved by BACnet. Each BACnet device within the same BACnet internetwork must have a unique device instance. One must be assigned to the EIPR if BBMD is enabled.

Device Description and Device Location can be used to configure additional identifiable information for the router. They are blank by default.


BACnet/IP Parameters

During normal EIPR operation with Firewall enabled, set the BACnet/IP UDP port and network for both WAN and LAN. The WAN values are used to receive the BACnet communication from the remote WAN side device. The LAN side values are used for the local BACnet/IP devices and should match the local BACnet/IP devices values. The WAN to LAN BACnet/IP communication is acheived via BACnet/IP to BACnet/IP (B/IP to B/IP) routing internally by the EIPR. With the Firewall disabled, only WAN side BACnet/IP UDP port and network are used and LAN side BACnet/IP Port and network are grayed out. In this case, the WAN side values should match the local BACnet/IP device values and BACnet/IP to BACnet/IP (B/IP to B/IP) routing is not required. The same UDP port is then used on both the remote WAN side and local LAN side BACnet/IP devices.


WAN BACnet/IP UDP Port (Default Value = 0xBAC0): This 16-bit hex value (normally in the range BAC0 - BACF) is set to BAC0 by default. Usually, this default value should not be changed. In typical networks, each BACnet/IP device will have the same UDP port.

WAN BACnet/IP Network (Default Value = 1): Like all networks in the BACnet internetwork, the BACnet/IP network must have a unique number (1 - 65534). Do not use addresses 0 or 65535 since these addresses are reserved.

LAN BACnet/IP UDP Port (Default Value = 0xBAC1): This 16-bit hex value (normally in the range BAC0 - BACF) is set to BAC1 by default. Usually, this default value should not be changed. In typical networks, each BACnet/IP device will have the same UDP port. This is only used if firewall is enabled. All LAN side BACnet devices should use the same UDP port number.

LAN BACnet/IP Network (Default Value = 2): Like all networks in the BACnet internetwork, the BACnet/IP network must have a unique number (1 - 65534). Do not use addresses 0 or 65535 since these addresses are reserved. This is only used if firewall is enabled.


Logging

BBMD Logging: Enable BBMD logging only when you have a BBMD issue. This will add a considerable amount of BBMD status information in the system log and could overwrite other logging information.The system log can be read via the Status ->BBMD Status ->View Log button.


Warning: If you enable BBMD when it is not needed, the router may attempt to find devices that are not present and thus traffic flow will be impaired and communication will suffer.