PLCs and PACs
Which one is right for you?

PLCs and PACs are industrial computers for use in manufacturing. They are both used for the same purpose. Both are used to control automation equipment to a reliable degree, with PLCs being used for over 40 years in the manufacturing sector. PACs are generally more complex than PLCs and are a more recent development to the manufacturing industry.

What are PLCs?

PLCs are devices with a single microprocessor and are programmed to undertake simple execution scans. They have limited memory and separate input/output (I/O) capacity. This means that PLCs are ideal when used for controlling simple applications.

They are often used for basic control schemes, where there isn’t a requirement for complex analogue and motion control. With that said, there are modern PLCs consisting of built-in networks, allowing them to communicate with other PLCs and human-machine interfaces (HMIs).

What are PACs?

PACs generally use two or more processors, and using this system is similar to using a PC and PLC combined. They are made up of different computer-based applications, which makes them more flexible to program.

PACs multitask easily as they operate in multiple domains including motion, process control and discrete. They are also used because of their interoperability and are useful for large applications, but can be scaled down for use on smaller ones too.

Due to the nature of PACs, they are compatible with other components, which allows them to communicate with other PLCs as well as manufacturing execution systems (MES) and enterprise resource planning systems (ERP).

Which one is right for you?

Both PACs and PLCs have their uses and their advantages for use in manufacturing. When deciding on which one is right for you, it’s important that you consider the differences between each system.

For controlling basic machines, PLC is largely seen as the better choice, especially for applications made up of discrete I/O.

If an application includes monitoring and control of a large number of analogue I/O points, then PAC is the system that would be most suited to this particular application.

PAC is also the best choice if an application involves an entire factory floor, as distributed I/O in large numbers will be required, which PAC systems can handle better than PLCs.

When a decision has been made on which system you will use, there’s a vast array of products to choose from. PLCs and PACs are often designed by scale, giving you a range of options to meet your requirements.