Use Of Sequencer Functions In Industrial Control

In this paper we will study one of the most commonly used functions in programmable logic controller (PLC) systems. This function is called the Sequencer. All programmable logic controllers (PLC) have this function. The sequencer function provides powerful capability for the PLC. This function and its applications are studied as part of a logic controller course in Electrical and Computer Engineering Technology (ECET) programs. Some PLC manufacturers refer to the sequencer function as the “drum controller”. However, in certain cases PLC manufacturers use the Table-to-Register or File-to-Word functions instead of the sequencer function [1]. These functions are not as versatile as the sequencer function. In this paper we will illustrate how students can utilize the sequencer function in the laboratory for controlling electromechanical actuators and robots. We will also illustrate how to control the time period between each sequencer step.