Yes, it is possible.

Different controller models offer high-speed counter functions of the following types:

• Shaft encoder, at resolutions x2 and x4

Selecting the shaft encoder function enables the counter to count both up (-3, -2, -1, 0, 1, 2, 3, …) and down (3, 2, 1, 0, -1, -2,-3 …).  Note that the input requires you to use pnp-type shaft encoders.

• High-speed counter

If you select the high-speed counter function that does not include Reset, note that you must reset it within your Ladder program.  This type of counter only counts up.

• High-speed counter + reset

If you select the high-speed counter function with reset, the counter is capable of counting up within the positive range, 0-32767.  This function uses the next-to-last input as a counter reset.  Since the reset is done via the hardware, the reset is immediate and independent of the program scan.

• Frequency measurement, at 100, 500, and 1000 msec

This counts the number of pulses over the selected period of time (sample rate): 100 msec, 500 msec, or 1000 msec (1 second), expressing the result in Hertz.  For example, 155 pulses counted over 100 msec is equal to 1550Hz; 155 pulses counted over 500 msec is equal to 310Hz.

Some of the sample programs installed together with U90 Ladder include high-speed counters of different types.

Please note that 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.