Programmable Logic Controller (PLC) is a digital computer used for the automation of various electro-mechanical processes in industries. These controllers are specially designed to survive in harsh situations and shielded from heat, cold, dust, and moisture etc. PLC consists of a microprocessor which is programmed using the computer language.
The program is written on a computer and is downloaded to the PLC via cable. These loaded programs are stored in non – volatile memory of the PLC. During the transition of relay control panels to PLC, the hard wired relay logic was exchanged for the program fed by the user. A visual programming language known as the Ladder Logic was created to program the PLC.
The main difference from other computers is that PLCs are armored for severe conditions (dust, moisture, heat, cold, etc) and have the facility for extensive input/out put (I/O) arrangements.
Disadvantages of Programmable logic controller (PLC, programmable controller) control:
1. There's too much work required in connecting wires.
2. There's difficulty with changes or replacements.
3. It's always difficult to find errors; And require skillful work force.
4. When a problem occurs, hold-up time is indefinite, usually long.
Advantages of Programmable logic controller (PLC) control:
1. Rugged and designed to withstand vibrations, temperature, humidity, and noise.
2. Have interfacing for inputs and outputs already inside the controller.
3. PLCs are easily programmed and have an easily understood programming language.
PLCs Applications
没有评论:
发表评论