Question

The three types of PLC timer instructions used by an Allen Bradley SLC 500 PLC are TON, TOF, and RTO. As we know, TON and TOF instructions refer to on-delay and off-delay non-retentive timers, while the RTO instruction is meant for the on-delay retentive timer.

Considering the material covered in this module, respond to the following:

How does an on-delay non-retentive timer differ from an off-delay non-retentive timer?

Suggest one simple PLC application in which you will use an off-delay non-retentive timer instead of an on-delay non-retentive timer? Why?

Answer 1