Omron CJ - INSTRUCTIONS REFERENCE MANUAL 07-2009 Reference Manual page 766

Operand Specifications
Word addresses
Area
CIO WR HR
C1 --- --- ---
C2
OK OK OK
D
Flags
Name Label
Error Flag ER
Function
PRV2(883) converts the pulse frequency input from high-speed counter 0, according to the conversion
method specified in C1 and the pulses/revolution coefficient specified in C2, and outputs the result to D
and D+1.
Select one of the following conversion methods by setting C1 to 0000 hex or 0001 hex.
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 ( ) specifies 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
• Rotation Speed Units = r/s (CJM1 CPU Unit Ver. 3.0 or later only)
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
• Rotation Speed Units = r/h (CJM1 CPU Unit Ver. 3.0 or later only)
When the second digit of C ( ) is 2, PRV2(883) calculates the rotation speed in r/h from the
frequency data and pulses/revolution setting.
Rotation speed (r/h) = (Frequency
• Range of Conversion Results
• Counter input method: Any method besides 4 differential phase mode
Conversion result = 00000000 to 000186A0 hex (0 to 100,000)
(If a frequency higher than 100 kHz has been input, the output will remain at the maximum value
of 000186A0 hex.)
• Counter input method: 4 differential phase mode
Conversion result = 00000000 to 00030D40 hex (0 to 200,000)
(If a frequency higher than 200 kHz has been input, the output will remain at the maximum value
of 00030D40 hex.)
(2) Frequency Calculation Method
When the CPU Unit is a CJ1M CPU Unit with version number 3.0 or later, there are two ways to
calculate the frequency of pulses input to high-speed counter 0.
• Standard Calculation Method (C1 = 0 00)
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 (about 1% error max. at
100 kHz).
CS/CJ/NSJ Series Instructions Reference Manual (W474)
AR T C DM EM
--- --- --- ---
---
OK OK OK OK
• ON if high-speed counter 0 is disabled in the settings.
• ON if C1 is not in the specified range (0000 or 0001).
• ON if the pulses/revolution setting in C2 is 0000.
• OFF in all other cases.
Pulses/revolution)
Pulses/revolution
Pulses/revolution)
Indirect DM/EM
addresses
Con-
stants
@DM *DM
DR
@EM *EM
--- --- ---
OK
OK
OK OK
--- ---
Operation
60
60 60
3. Instructions
Registers Flags
Pulse
bits
Indirect
IR TK CF
using IR
---
--- --- ---
OK
TR
bits
--- ---
3
729