Industrial Cells
In industry, there are many cells used throughout the factory. The control system for those cells is your PLC. Some of the most common ones are:
Distributing
Testing
Assembly
Pick & Place
Sorting
For the proper operation of those cells, we need sensors and actuators to allow the PLC to execute the programmed logic.
https://youtu.be/tpXW6qWoJGA
https://youtu.be/R3RWuqfFrNY
Let's consider the scenario of the sorting station from FESTO that you will work on in your future PLC courses:
The Sorting station sorts the workpieces onto three chutes. The detection module is capable of verifying the presence of red, black, and metallic workpieces.
Workpieces placed onto the beginning of the conveyor belt are detected.
The workpieces are stopped by a pneumatic stopper to determine their characteristics.
The sensors in the detection module ascertain the workpieces’ material and color (black, red, metallic).
The workpieces are sorted onto the appropriate chutes by means of electrically operated deflectors.
A retroreflective sensor monitors the fill levels of the chutes.
Think about how many and what types of sensors are needed for that system. These sensors will provide the input signals to the PLC, which will generate the output to turn on the conveyor belt, pneumatic stopper, or deflectors.
In your original post, describe the process flow step by step. For example, the initial check would be similar to:
Sequence
1. Workpiece detected at the beginning of the conveyor belt
2. Conveyor motor on
3. Color/material detection
Sequence
- Workpiece detected at the beginning of the conveyor belt
- Conveyor motor on
- Color/material detection
- Pneumatic stopper activated
- Workpiece sorted onto appropriate chute
- Conveyor motor off
- Fill level sensor activated
- Repeat
- A photoelectric sensor to detect the workpiece at the beginning of the conveyor belt.
- A conveyor motor sensor to turn on the conveyor belt.
- A color sensor to detect the color of the workpiece.
- A material sensor to detect the material of the workpiece.
- A pneumatic stopper sensor to activate the pneumatic stopper.
- A deflector sensor to sort the workpiece onto the appropriate chute.
- A fill level sensor to monitor the fill levels of the chutes.
- The photoelectric sensor would detect the workpiece at the beginning of the conveyor belt.
- The conveyor motor sensor would turn on the conveyor belt.
- The color sensor would detect the color of the workpiece.
- The material sensor would detect the material of the workpiece.
- The pneumatic stopper sensor would activate the pneumatic stopper.
- The deflector sensor would sort the workpiece onto the appropriate chute.
- The fill level sensor would monitor the fill levels of the chutes.
- The process would then repeat.
- The speed of the conveyor belt will need to be adjusted to ensure that the workpieces are not damaged.
- The sensors will need to be calibrated to ensure that they are accurately detecting the workpieces.
- The PLC logic will need to be tested to ensure that it is functioning properly.