Problem Description

parts’ detection.

Give this detection, as an input to Up Counter which is incremented with each part’s detection.

Set counter preset value to 1000.

Operate Solenoid for a few seconds until the part is diverted for quality check.
PLC Program
Here is PLC program to Sort Parts for Quality Control on Conveyor, along with program explanation and
run time test cases.
List of Inputs and Outputs
I:1/14 = Start
(Input)
I:1/15 = Stop
(Input)
I:1/0
= Detector input
(Input)
B3:0/0 = Latching Coil
(Bit)
O:2/0
= Conveyor Motors
(Output)
O:2/1
= Solenoid to operate gate
(Output)
C5:0
= Up Counter to count 1000 parts (Counter)
T4:0
= Timer to operate solenoid
(Timer)
-(RES)- = Reset counter value
(Timer/Counter)

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Ladder
 
Diagram
 
to
 
perform
 
this
 
operation
Program Description

RUNG000 is Master Start and Stop the process.

RUNG001 operates Conveyor Motors with address O:2/0 to start moving parts to other process. This is
started as soon as Start PB I:1/14 is pressed.

RUNG002 comprises Up Counter which counts the number of parts detected by the detector which is
connected to I:1/0. Whenever a part is detected, I:1/0 goes high incrementing accumulator value of C5:0
Counter.

When 1000 parts are counted, done bit is generated which is used to operate Solenoid Coil in RUNG003. It
allows the current to pass and solenoid is operated.

Assuming that it takes 2secs to divert the part for quality check, 2secs of timer T4:0 is used. This timer bit
T4:0/DN resets the counter value to 0 which in turn unlatches solenoid coil O:2/1 taking gate to its main position.