Choosing the right PLC for your application

The programmable logic controller (PLC) that you choose is based on the type of process or machine it will be controlling.

A number of factors will affect the selection and our guide to the steps you would make in the selection process is available for download here.

Three performance levels of standard PLC exist within most manufacturers ranges:

• Logic controllers - more information
• Compact PLC - often a single PLC unit that combines both the processor, inputs & outputs
• Advanced PLC - normally a modular system made up of a processor module, and separate I/O modules

The controller (sometimes called a CPU - Central Processing Unit) performance level you select will be based on the type of calculations or functions the controller will be required to make during the process, the speed of the process, and the amount of I/O it must handle.

Brands & performance levels

The chart below acts as a useful guide showing the relative performance of manufacturer PLC models and the choice of brands available.


Manufacturer's key PLC range that aligns with the two CPU performance levels

Compact PLCs

Find out more about a typical Compact PLC application.

Twido compact and modular PLC Find out more Twido manual TwidoSuite software (318MB download)	CP1L compact PLC Find out more CP1L manual Omron CX-One CX-One Lite software	FX1N, FX2N, & FX3U PLC See the range Programming & hardware manual FX training courses FX configurator GX developer demo (37MB download) GX Developer FX software
Simatic S7-200 PLC See the range STEP 7 Micro/WIN V4.0 software S7-200 2 Hour Primer Guide S7-200 Programmable Controller System Manual	AC500 scaleable PLC Find out more ABB Control Builder PS501 System Description, Vol. 2 - Hardware Request your FREE promotional copy of AC500 Control Builder software

Advanced PLCs

Find out more about a typical Advanced PLC application.

Modicon M340 PLC Find out more Modicon M340 brochure Unity Pro software	CJ1M Modular PLC See the range Operation manual Omron CX-One CX-One software	Q Series rack-based PLC See the range Programming manual GX developer demo (37MB download) GX Developer software
Simatic S7-300 PLC See the range S7-300 manuals Siemens Training Centre Siemens Step 7 Lite software	Moeller XC See the range More info Moeller X-Soft Professional demo version