DC Motor Control Using PLC

DC Motor Control Using PLC

DC motorcontrol with a Programmable Logic Controller (PLC) is a typical use in industrial automation. The PLC controls the motor’s speed and direction using input signals from sensors & other devices.

PLC Programming

The PLC program is written using a programming language like

  • Ladder Logic,
  • Function Block Diagram, or
  • Structured Text.

The software contains logic statements that control the motor’s speed & direction based on the input signal. The PLC runs the program at a predetermined scan rate, which defines the frequency of motor control.

Motor Control Logic

The motor control logic contains statements that verify the input signals and alter the motor’s speed & direction accordingly.

Ex: A logic statement could check to see if a sensor detects an object & subsequently slow or stop the motor.

Output Module

The PLC’s output module controls the speed and direction of the motor. The output module transmits a signal to motor driver, which subsequently regulates the motor’s speed and direction.


  • Utilizing a PLC for DC motor control has various benefits, including:
  • The PLC can be configured and programmed to control motor’s speed & direction using a variety of input signals.
  • The PLC can be engineered to be extremely dependable and fault tolerant.
  • The PLC can simply expanded to operate numerous motors.

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