ADC AD-410 service manual

b.PLC (Programmable Logic Controller)

1)The PLC (Programmable Logic Controller) can consist of one (1) or two (2) modules; a main module and in some cases an expansion module is used for additional inputs and outputs.

NOTE: The information listed below is generic in nature, refer to blueprints for specific details.

a)The main PLC (Programmable Logic Controller) module has eight (8) input relays which are labeled #0 through #7 and six (6) output relays labeled #200 through #205.

(1)Input Relays

Input relays #0, #1, #2, and #3 are set up as users inputs to signal what specific function is to be performed (i.e., open-close door, load-unload tilted, open doors, and level dryer). 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 in on, the appropriate L.E.D. (light emitting diode) on the PLC will be illuminated.

For input relay #4 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 (Programmable Logic Controller) which in turn rotates the tumbler (drum and basket) through either output relay #204 or output relay #205 providing the lint door is closed. This interlock is performed through PLC input #16 (lint door closed), or in some cases contactor B is used to interrupt the 24 VAC signal from reaching the drive contactors and the tilting solenoids.

(2)Output Relays

Output relay #200 controls the open front door function. When this signal is energized, the pneumatic valve opens allowing air into the two (2) door cable cylinders, which in turn opens the front doors.

The end of cycle (EOC) output (relay #202) switches on after an air jet signal is received. This output relay will stay illuminated until the dryer is attended to.

During a drying cycle, the PLC (Programmable Logic Controller) monitors the status of the Phase 5 microprocessor controller (computer) "HEAT ON/OFF" signal. Input relay #13 is the "control status" of the front and rear gas valves and monitors the state of both the front burner and rear burner "Air Flow" switches. If a fault is sensed, input #13 L.E.D. (light emitting diode) turns off at that point and output relay #203 "HEATER FAULT" indicator and output relay #202 "END OF CYCLE" indicator will begin to flash at a rate of one (1) flash per second. Both indicators will flash until the operator presses the "HEATER FAULT" indicator/ reset push-button.

Output relay #204 (drive forward) and output relay #205 (drive reverse) are used to perform jog functions.

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