BMTX BCU components
BMTX-SVN01C-EN 3
BMTX BCU components
A BCU provides centralized building control through communication with
unit control modules (UCMs), PC Workstations, and other BCUs to exe-
cute all application programs.
The BMTX BCU consists of a main circuit board and a termination board
(see Figure 2 on page 4) both housed in a NEMA-1-rated enclosure. The
components on the boards are as follows:
• A termination board connected by a ribbon cable to the BMTX BCU
main board for terminal wiring of UCM communication links, 24 V
power, BACnet™ serial connection, and binary inputs.
• Four UCM communication links are predefined on the BMTX BCU to
support one isolated Comm3 link, two non-isolated Comm4 links, and
one Comm 5 link. For more information, see Chapter 5, “UCM com-
munication link wiring and topology.”
• The BACnet serial connection is a dedicated EIA-232 serial port.
• Two binary inputs for use as status or pulse inputs.
• Communication jacks on the termination board to allow access to the
Comm4 and Comm5 links using a service tool, such as the Rover ser-
vice tool.
• A mini-monitor port on the termination board for attaching a PC with
a straight-through EIA-232 cable to access built-in diagnostic soft-
ware. Intended for use by trained service technicians.
• A seven-segment LED display on the main board for displaying BCU
operation status. LED operation and codes are described in Chapter
10, “BCU operation and communication status.”
• A DIP switch for setting the BMTX BCU address on the main board.
• A connection on the main board for attaching the optional operator
display. For information about the operator display, see the BCU
Operator Display operations guide.
• A connection on the main board for Ethernet communication.
• A connection on the main board for an on-board modem. No external
modems are supported for dial-out connections.