Module 11 - PLC Timers
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.
• 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 OFFdelay instruction.
• Write a ladder logic program using timers.
• Describe the operating principle of retentive timers.
• Explain the purpose of cascading timers.
• Define reciprocating timers.