This module is intended to provide students with an overview of PLC timers and their application in industrial control circuits. Allen-Bradley timing functions such as TON, TOF, and RTO are discussed in detail and the theory is reinforced through lab projects using lab simulation software. In addition, students will learn practical programming techniques for timers including cascading and reciprocating timing circuits.

Learning Outcomes:

Upon completion of this module the student will be able to:

• Name two types of relay logic timers.
• List the four basic types of PLC timers.
• Describe the function of a time-driven circuit.
• Differentiate between an ON-delay and an OFF-delay instruction.
• Write a ladder logic program using timers.
• Describe the operating principle of retentive timers.
• Explain the purpose of cascading timers.
• Define reciprocating timers.