PLC interfaces with existing automation to drive two process conveyors

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This PLC improves operator convenience and eliminates process variability.

overall view of process conveyors

In my client's experimental recycling operation, batches of rubber pass through an automated grinder (right) then, via conveyor, to the refiner mill at left. After a specified period in the refiner the batch is discharged by reversing the direction of a second conveyor. Originally it was the machine operator's responsibility to wait for the grinder to unload, then engage conveyor 1 to load the refiner. After the process delay (timed manually) s/he would unload the refiner by temporarily reversing conveyor 2.

Automating the conveyors makes the batches more consistent since the process delay is not subject to human error. Automation also makes the operator's job easier.

I selected an Omega Engineering HE-XE102 PLC to run the show. With this unit the HMI is included, and virtual controls on the LCD graphics screen relieve the need for hardware switches and indicators. The program I provided makes all process variables easily alterable (though protected by password), and a diagnostic screen displays the status of inputs and outputs during setup and troubleshooting.

refiner and its two conveyors the panel during installation
wiring inside PLC panel
Servicing the Unserviceable
extra (main index)
copyright notice (Jeff Laughton)