Automatic Sequencer – Basic

This is the main control program of the PLC system.  It is split into 2 parts, the Sequencer and the Commands programs.  The Sequencer program checks that conditions are met or PLC inputs are on, before moving to the next step of the automatic sequence.  The Commands program is to control the PLC outputs based on the step number of the sequence.

The sequence of operations should be written down before programmed to get a basic understand of the theory of operations of the equipment.  Below are some examples of what to consider for each piece of equipment when writing a sequencer:

Sequencer Steps and Commands:

Equipment and Device Controls Operations:

Sequence Program

Command Program