Milltronics Level Genie, Инструкция по эксплуатации

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ECHO PROCESSING LOGIC
1. General Description
The digital echo processor establishes the necessary
timing and limit functions. Coincidently, statistical
techniques are employed to discriminate against response to
spurious noise inputs.
2. Timing & Limit Generation
IC 3-1, IC 3-2 and IC l-l form a typical hybrid monstable
multivibrator. This type of pulse generator is extremely
stable over a wide range of temperature and/or bus variations.
Repetition rate generator ICl-3 triggers the timing
monostables which generate the following functions; pulse
width, blanking,
the'NEAR' setpoint, the'FAR'setpoint, and
limit. (Maximum Range)
Switch SWl, the maximum range switch, allows the range
to extend to either 5 feet or 10 feet.
3.
Alarm Point Recognition
IC 5-1, IC 5-2, IC 6-l and IC 6-2, are C-MOS NOR gates.
Each gate accepts two inputs, the processed echo and one of
the timing functions. The order in which the timing functions
are connected to the gate inputs determines the mode of operation
of the unit, ie. Hi-Lo alarm, Lo-Lo alarm. Plug-in programming
modules allow easy field modification.
Another toggle on switch SW1 allows introduction of either
a 3 second or 10 second delay on alarm. Moving the third toggle
(SW1) from run to calibrate removes these delays.
Resistors R62 and R65 about IC 2-3 and IC 2-4 provide
alarm point hysterisis of 0.5 in. (12.5mm) per foot of range.
3-3