Frequency Measurement - Omron CP1E CPU UNIT SOFTWARE User Manual

11-2-5 Frequency Measurement

Overview
This function measures the frequency of the high-speed counter (input pulses.)
The input pulse frequency can be read by executing the PRV instruction. The measured frequency is
output in 8-digit hexadecimal and expressed in Hz. The frequency measurement function can be used
with high-speed counter 0 only.
The frequency can be measured while a high-speed counter 0 comparison operation is in progress.
Frequency measurement can be performed at the same time as functions such as the high-speed
counter and pulse output without affecting the performance of those functions.
Reading the High-speed Counter Frequency with a PRV Instruction
Execution condition
Precautions for Correct Use Precautions for Correct Use
The frequency measurement function can be used with high-speed counter 0 only.
Specifications
Item
Number of frequency mea-
surement inputs

Frequency measurement

range
Measurement method
Stored data Unit
Output data
range
* If the frequency exceeds the maximum value, the maximum value will be stored.
CP1E CPU Unit Software User's Manual(W480)
@PRV
C1: Port specifier (example for high-speed counter input 0 (fixed))
#0010
#0013 C2: Control data for reading frequency (10-ms sampling)
S: First destination word
D100
15
Present frequency
D100
data lower bytes
Present frequency
D101
data upper bytes
1 input (high-speed counter 0 only)
High-speed counter 0:
Differential phase inputs: 0 to 50 kHz
All other input modes: 0 to 100 kHz*
Execution of the PRV instruction
Hz
Differential phase input: 0000 0000 to 0003 0D40 hex
All other input modes: 0000 0000 to 0001 86A0 hex
11 High-speed Counters
0
High-speed counter frequency
that was read
Specifications
11
11-13