Examples of Timer Functions and Applications in PLC

On delay Timer

Output B comes on at a specific set time after output A is turned on. When A is turned off, B also goes off.

Limited on time Timer

A and B go on at the same time. B goes off after specific set time period, but A remains on.

One-shot operation Timer

Output B goes on for a specified time after output A is turned on. Output B will run for its specified time interval even if A is turned off during the B timing interval.

Interval time within a cycle Timer

We may require that an output come on 7.5 seconds after system startup, remain on for 4.5 seconds, and then go off and stay off.

The interval would repeat only after the system is shut off and then turned back on.