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High-speed Counter/Pulse Output Instructions Section 3-20
Converting Frequency to Rotation Speed (C1 = 0@*0 hex)
If C1 is 0@*0 hex, PRV2(883) calculates the rotation speed (r/min) from the
frequency data and pulses/revolution setting. The second digit of C (@) speci-
fies the units and the third digit (*) specifies the frequency calculation method.
1. Rotation Speed Units
• Rotation Speed Units = r/min
When the second digit of C (@) is 0, PRV2(883) calculates the rotation
speed in r/min from the frequency data and pulses/revolution setting.
Rotation speed (r/min) = (Frequency
÷ Pulses/revolution) × 60
• Rotation Speed Units = r/s
When the second digit of C (@) is 1, PRV2(883) calculates the rotation
speed in r/s from the frequency data and pulses/revolution setting.
Rotation speed (r/s) = Frequency
÷ Pulses/revolution
• Rotation Speed Units = r/hr
When the second digit of C (@) is 2, PRV2(883) calculates the rotation
speed in r/hr from the frequency data and pulses/revolution setting.
Rotation speed (r/hr) = (Frequency
÷ Pulses/revolution) × 60 × 60
• Range of Conversion Results for CP1H X/XA and CP1L CPU Units
• Counter input method: Any method besides 4
× differential phase mode
Conversion result = 0000 0000 to 0001 86A0 hex (0 to 100,000)
• Counter input method: 4
× differential phase mode
Conversion result = 0000 0000 to 0003 0D40 hex (0 to 200,000)
(If a frequency higher than 200 kHz has been input, the output will re-
main at the maximum value of 0003 0D40 hex.)
• Range of Conversion Results for CP1H Y CPU Units
• Counter input method: Any method besides 4
× differential phase mode
Conversion result = 0000 0000 to 000F 4240 hex (0 to 1,000,000)
• Counter input method: 4
× differential phase mode
Conversion result = 0000 0000 to 001E 8480 hex (0 to 2,000,000)
(If a frequency higher than 2 MHz has been input, the output will re-
main at the maximum value of 001E 8480 hex.)
Note If the input frequency exceeds the maximum input frequency, the
output value will remain at the maximum output value. The maxi-
mum input frequency depends on the function being used and the
high-speed counter port. Refer to the Operation Manual for details.
(For a CP1H Y CPU Unit, the conversion results (r/h) will remain at
FFFF FFFF hex if an overflow occurs.)
2. Frequency Calculation Method
There are two ways to calculate the frequency of pulses input to high-
speed counter 0.
a. Standard Calculation Method (C1 = 0@00)
The count is calculated by counting each pulse regardless of the fre-
quency. At high frequencies, the rising or falling edges of some pulses
will be corrupted, resulting in errors (about 1% error max. at 100 kHz).
b. High-frequency Calculation Method
In this case, the counting method is switched at high and low frequen-
cies.
• High-frequency counting (C1 = 0@10, 0@20, or 0@30)
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