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3. Instructions

740

CS/CJ/NSJ Series Instructions Reference Manual (W474)

z Reading Pulse Output or High-speed Counter Frequency (C = 00@3 hex)

If C is 00@3 hex, PRV(881) reads the frequency being output from pulse output 0 to 3 or the frequency

being input to high-speed counter 0 and stores it in D and D+1.

0000 or 0001 hex (Reading the frequency of pulse output 0 to 3)

0000 0000 to 0001 86A0 hex (0 to 100,000)

0010 hex (Reading the frequency of high-speed counter 0)

Counter input method: Any input method other than 4× differential phase mode:

Result = 0000 0000 to 0001 86A0 hex (0 to 100,000)

Note If a frequency higher than 100 kHz has been input, the output will remain at the maximum value of 0001

86A0 hex.

Counter input method: 4× differential phase mode:

Result = 0000 0000 to 0003 0D40 hex (0 to 200,000)

Note If a frequency higher than 200 kHz has been input, the output will remain at the maximum value of 200,000

decimal.

z Pulse Frequency Calculation Methods

• Pulse Output:

The output frequency can be read by executing the PRV(881) instruction.

• High-speed Counter:

When the CPU Unit is a CJ1M CPU Unit with unit version 3.0 or later or a CJ2M CPU Unit, there are

two ways to calculate the frequency of pulses input to high-speed counter 0.

• Standard Calculation Method (Earlier Method): The count is calculated by counting each pulse

regardless of the frequency. At high frequencies, the rising or falling edges of some pulses will be

corrupted, resulting in errors (roughly 1% error max. at 100 kHz).

z Reading the Results of Range Comparison

(C = 0002 hex)

If C is 0002 hex, PRV(881) reads the results of

range comparison and stores it in D as shown in

the following diagram.

Results for Eight Ranges

Results for 1 to 32 Ranges (CJ2M Only)

015

000 0 0 0 0 0

Comparison Result 1