efficient control of the GTGS and for backup
DISPLAY CONTROL/DIGITAL METER--
purposes.
Receives, from the computer control, the digitized
monitor data. It then directs this data to the asso-
BUS CONTROLLER--Generates
the
ciated digital display card located on the LOCOP
system's real time clocks and the synchroni-
front door. Up to 16 channels may be handled.
zation signals. These are required to allow
the two computer control systems to operate
ANALOG INPUT/MULTIPLEXER, ANA-
together.
LOG-TO-DIGITAL CONVERTER (ADC),
AND DIGITAL-TO-ANALOG CONVERTER
I/O MEMORY--Contains the data storage
(DAC)--Comprise the monitor data handling
memory space. It is independent of the computer
system of the LOCOP. The analog
control memory. This memory may be used by
input/multiplexer has 8 input circuits with 10-mA
either computer control system where data needs
output current sources. These inputs are designed
to be shared between them.
to accept a 0- to 10-volt dc signal. The data can
be attenuated or amplified by electronics or the
CONTACT BUFFER--Monitors 16 inputs to
control program. Once conditioned, this card
interpret a switch closure. Electronics are included
multiplexes the data to be digitized by the ADC
to interrupt the microprocessor so the special task
card. The digitized data is then sent to the I/O
requested by the switch can be handled. The card
memory card for storage. The control program
may be programmed to accept normally open or
then conditions this data for the digital displays
and analog output card. The analog output card
closed contacts. It will interrupt the micro-
processor on both transmissions of the switch.
can convert up to 8 channels of data to a 0- to
Each LOCOP system has two contact buffer
10-volt dc signal. This analog signal can be used
cards.
depending on the control program. Each LOCOP
system has two analog input cards, two analog
SWITCH BUFFER--Monitors 8 inputs to
output cards, and one ADC card.
interpret a switch closure. It differs from the
contact buffer by interrupting the microprocessors
VIBRATION MONITOR--Monitors the
only upon initial closure. The switch release is not
engine vibration pickup and scales it for control
buffered. Each LOCOP system has two switch
purposes. The card also splits the signal and sends
buffer cards.
it to the remote monitor outputs and analog input
card. Also, an electronic switch circuit detects high
LAMP DRIVER--Contains 8 output driver
vibration. This switch signals the microprocessor
circuits used to illuminate the visual indicators on
control via a contact buffer input.
the LOCOP front panel. The indicators can burn
steadily or flash, depending on the control
ALARM BOARD--Generates the alarm tones
program. If a lamp fails, circuitry is provided to
required for the audible alarm system. Seven tones
interrupt the microprocessor to indicate an
are possible. The circuitry can also be used to
internal failure. Each LOCOP system has three
adjust the volume of the audible alarm.
lamp driver cards.
I/E CONVERTER--Converts current inputs
(I) to voltage outputs (E). It converts the 4- to
RELAY CONTROL--Contains 8 relays, all
20-mA pressure transducer current outputs to a
independently controlled by the control program.
0- to 10-volt dc signal. The circuitry is also used
Each relay provides normally open and normally
to calibrate the rpm/TIT analog meter on the
closed contacts. Circuitry also detects a failure of
LOCOP front panel. An electronic switch closure
the driver circuits. The circuits will interrupt the
is adjustable for any predetermined rpm set point.
microprocessor to indicate an internal failure.
Each LOCOP system has two relay control cards.
ALLISON SPEED/TEMP CONTROL BOX--
SOLENOID DRIVER--Contains 6 solenoid
Generates switch closures required by the
computer control system to control the GTGS.
driver circuits. They are independently controlled
These include engine speed as well as engine TIT
by the control program. The circuitry detects a
set points. The unit also supplies the signals for
failure of the driver circuits or a shorted solenoid.
the analog rpm/TIT meter located on the LOCOP
This circuit will interrupt the microprocessor to
indicate an internal failure.
front door.
3-51