Omron CP1H CPU Operation Manual page 261

High-speed Counters
Pulse Frequency Conversion
Procedure
1,2,3...
Restrictions
Item
Measurement method
Output data range
The pulse frequency input to a high-speed counter can be converted to a rota-
tional speed (r/min) or the PV of the counter can be converted to the total
number of rotations. The converted value is output as 8-digit hexadecimal.
This function is supported only for high-speed counter 0.
Frequency−Rotational Speed Conversion
The rotational speed in r/min is calculated from the pulse frequency input to a
high-speed counter and the number of pulses per rotation.
Counter PV−Total Number of Rotations Conversion
The total number of rotations is calculated from the present value of the
counter and the number of pulses per rotation.
1. High-speed Counter Enable/Disable Setting (Required)
Select the Use high speed counter 0 Option in the PLC Setup.
2. Pulse Input Mode Setting (Required)
Set the High-speed Counter 0 Pulse Input Mode (Input Setting) in the PLC
Setup.
3. Counting Mode Setting (Required)
Set the High-speed Counter 0 Counting Mode in the PLC Setup.
If ring mode counting is selected, set the Circular Max. Count (max. ring
count) in the PLC Setup.
4. Reset Method Setting (Required)
Set the High-speed Counter 0 Reset Method in the PLC Setup.
5. Execute PRV2(883) as described below (required).
Converting the Frequency to a Rotational Speed
Execute PRV2(883) with the following operands.
C: Control data (Set to #0000 for frequency-rotational speed conversion.)
P: Coefficient (pulses/rotation (hex))
D: First word for result
Converting the Counter PV to the Total Number of Rotations
Execute PRV2(883) with the following operands.
C: Control data (Set to #0001 for counter PV-total number of rotations con-
version.)
P: Coefficient (pulses/rotation (hex))
D: First word for result
Pulse frequency conversion is possible only for high-speed counter 0.
Specifications
Execution of the PRV(881) instruction
Units: Hz
Range:
Differential phase input: 0000 0000 to 0003 0D40 hex
(Y models: 0000 0000 to 0007 A120 hex)
All other input modes: 0000 0000 to 0001 86A0 hex (Y
models: 0000 0000 to 000F 4240 hex)
Section 5-2
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