HMI
Product Counting with HMI
What is product counting with an HMI?
It is a PLC application in which products on a conveyor are counted by a sensor and the target quantity is entered on the operator panel (HMI). When the target is reached the conveyor stops; in automatic mode the counter resets itself and the conveyor keeps running.
Where is it used?
It is used for batch counting on packaging, filling, bottling and carton lines. Letting the operator enter the target quantity on the screen without changing the program makes production flexible.
PLC and HMI wiring
The conveyor motor runs through a contactor and the sensor on a PLC input. The program counts the sensor's rising edge, so a product standing in front of the sensor is not counted more than once. The target value is written from the HMI to the PLC.
What it teaches
Edge detection, entering values on a screen and counter-driven lines are the most common applications of HMI-based automation.
Parts used
Run it in the simulator.
This circuit is ready in the CoilPath library. Open it, press the buttons and follow the current. It also comes with a wiring view and a panel layout.