Data Bus Isolation Amplifiers

Data bus isolation amplifiers are the interfacing devices for the GSE/LPS and the SRB MDMs. They transmit or receive multiplexed data in either direction. The amplifiers enable multiplexed communications over the longer data bus cables that connect the orbiter and GSE/LPS. The receiving section of the amplifiers detects low-level coded signals, discriminates against noise and decodes the signal to standard digital data at a very low bit error rate; the transmit section of the amplifiers then re-encodes the data and retransmits it at full amplitude and low noise.

Data bus couplers couple the vehicle multiplexed data and control signals from the data bus and cable studs connected to the various electronic units. The couplers also perform impedance matching on the data bus, line termination, dc isolation and noise rejection.

Each data bus isolation amplifier is 7 by 6 by 5 inches and weighs 7.5 pounds. Each data bus coupler is 1 cubic inch in size and weighs less than 1 ounce. The contractor for the data bus isolation amplifiers and data bus couplers is Singer Electronics Systems Division, Little Falls, N.J.