Timer Functions in Ladder Logic

The timing block functions are used with various contact arrangements and in multiples to accomplish various timing tasks.

Typical industrial timing tasks include timing of the intervals for welding, painting, and heat treating.

Timers can also predetermine the interval between two operations.

With a PLC you can utilize as many timer blocks as you need, within the PLC memory limitations.

Basic Timing Functions

Basic PLC TIME DELAY ON function and some other derived timing functions.

Typical of the derived functions are

  1. TIME DELAY-OFF,

  2. interval pulse timing,

  3. Multiple pulse timing of more than one process operation.

Timer Variables

One major advantage of the PLC timer is that its time may be a programmable variable time as well as a fixed time.

The variable time interval may be in accordance with a changing register value.

Another advantage of the PLC timer is that its timer accuracy, repeatability, and reliability are extremely high because it is based on solid-state technology.

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