Comtech EF Data MBT-4000B - Manual (Page 29)

4-1
Chapter 4. Redundant Configuration
4.1 General
The MBT-4000B is designed to operate in both stand-alone and redundant configurations. Every
MBT-4000B base contains the circuitry and logic necessary to perform all the functions of a
backup controller in either a single base and dual base configuration. The Bias Tee side of the
MBT 4000B provides the 10 MHz reference and DC voltage for the LNB. This power supply
features current monitoring with programmable failure limits. Overcurrent and undercurrent
failures can participate in overall fault indication and redundant switchover criteria.
Each MBT-4000B base includes one “AUX COMM” connector. This connector includes a logic
input intended to be connected to contact closure fault indications of external equipment. Thus,
external equipment failure may participate in overall fault indication and redundant switchover
operation. The “AUX COMM” connector also has a user programmable I/O pin. When
programmed as an output, this pin indicates the online/offline position of the switch associated
with the BUC. This signal can be used to mute the external offline amplifier.
Each MBT-4000B base includes two “switch drive” connectors. Each of these connectors is
intended for driving and monitoring a 28V latching switch. In most installations, one switch
drive connector will drive an RF waveguide switch, while the second switch drive connector will
drive an IF(L-Band) co-axial switch.