This worksheet is intended to function as a checklist of the most important areas to consider when researching a Programmable Logic Controller (PLC).

Certain PLCs may not support every type of instruction. You will need to choose a PLC that supports all instructions that you may need for a specific application. For example, built-in PID functions are much easier to use than writing your own code to perform closed-loop process control.

Once you have recorded the information on the worksheet and determined your requirements, use this sheet to find a PLC that meets your requirements. With your requirements outlined, it will be much simpler to find product with the necessary number of I/O points, features, memory, etc. that your application requires.