Configuring a High-Speed Counter

Certain digital inputs on onboard inputs, Snap-in, I/and I/O Expansion modules can be used as high-speed counters in the following modes:

High-Speed counter
High-Speed counter with Reset
High Speed Inputs with Reload
Shaft encoder
Frequency Measurer

Note ♦

When you select High-Speed Counter with Reset, the controller uses an additional input for reset; shaft encoders also require the use of two inputs.
When you select High Speed Inputs with Reload, you cannot set the Reload input to Frequency Measurement.

High-speed counters are built into the hardware, you define them as part of the controller's hardware configuration by first selecting the counter type and then linking it to an operand that contains the counter value.

Compare Functions and Counter Values

The high-speed counter value is read once during every program scan. For this reason, do not use the Equal (=) function together with high-speed counter values. If the counter does not reach the value required by the Equal function during the actual program scan, the function cannot register that the value has been reached. Use functions Greater Than Or Equal To ( ≥) and Lesser Than Or Equal To ( ≤).