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a) The Programmable Logic Controller (PLC) module has thirteen (13) input relays, which are
labeled #0 through #13 and nine (9) output relays labeled #0 through #9.
(1) Input Relays
Input relays #0, #1, #2, and #3 are set up as user inputs to signal what specific function is to
be performed (i.e., load, unload, tilt, and front identifier). These input relays are charted as
1 and 0 (1 is logic on and 0 is logic off). When either an input relay or an output relay is on,
the appropriate light emitting diode (L.E.D.) on the PLC will be illuminated.
For input relay #7 to turn on, the left and right front doors must be completely open. Once
these doors are completely open, the jog forward (input #5) and jog reverse (input #6) can
turn on through the PLC, which in turn rotates the basket (tumbler and drum) through either
output relay #0 or output relay #1 providing the lint door is closed. This interlock is performed
through PLC input #9 (lint door closed), or in some cases, the drive or blower overload may
interrupt the 24 VAC signal from reaching the drive contactors.
(2) Output Relays
Output relay #2 controls the open front door function. When this signal is energized, the
pneumatic valve opens allowing air into the 2 door cable cylinders, which in turn opens the
front doors.
Output relay #0 (drive forward) and output relay #1 (drive reverse) are used to perform jog
functions.