Top 18 Advantages and Disadvantages of PLC in Industrial Automation

As a part of PLC automation tutorials, in this article, we are going to learn about the advantages and disadvantages of programmable logic controller (PLC) systems.

Let’s dive into,

Advantages and Disadvantages of PLC in Industrial Automation

When we talk about PLC, there should be some benchmarks to compare. Here we are comparing PLC with electromagnetic relays.

Advantages (or Pros) of PLC

1. The highlighting advantage of PLC is to increase the reliability and flexibility in industrial automation.
2. PLC is available in a compact size, especially compact PLC.
3. PLC is suitable for simple to complex control systems.
4. An industrial automation network built based on PLC is simple to operate and understand than a relay network.  
5. PLC has a fast scan time (near about 10-15 ms for compact PLC). It requires very less operation time to perform any task.
6. PLC gives a fast response to the connected system.
7. PLC provides high accuracy as compared to the relay network.
8. PLC needs low maintenance.
9. Modular PLC gives scalability for operating and controlling connected devices or systems.
10. The compact PLC has a lower cost.
11. It has remote control capability.
12. It gives supervisory control capability.
13. PLC can operate in extreme environments.
14. In the case of PLC design, if anything goes wrong, one can easily troubleshoot the problem with the help of a debugger.
15. PLC programs are easy to write and understand. There are many programming languages used in PLC. Out of them, the ladder diagram is very popular and user-friendly.

Thus, we have learned that PLC is more beneficial and useful in automation.

Let’s move to another side of it.

Disadvantages (or Cons) of PLC

16. You can operate one program at a time in a compact PLC.
17. In the case of PLC, we can not use software and parts of one PLC manufacturer in another PLC manufacturer.
18. When power restores, PLC automatically starts. It can damage the system. To avoid the damage, you can program the output to go to the fail-safe mode.

These are only a few disadvantages as compared to the advantages.

If you have any queries or points to add related to the pros and cons of PLC, feel free to write a comment.

Read more related

• Modular PLC vs Compact PLC
• PLC vs Relay
• Useful communication protocols for PLC
• Input and output modules of PLC
• PLC programming languages
• Ladder diagram PLC programing language
• PLC programming instructions

Online PLC Quiz:

If you are ready for an online test, here is a PLC Automation Quiz.

Happy PLC Learning!