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.