Overview - Omron SYSMAC CJ Series User Manual

7 High-speed Counters
7-1

Overview

7-1-1

Overview

High-speed counters are used to measure high-speed pulse input signals that cannot be measured by
counter (CNT) instructions.
Applications
• Detecting the position or length of a workpiece with an input from an incremental rotary encoder.
• Measuring the speed of a workpiece from its position data using frequency measurement and
rotational speed conversion.
• High-speed processing according to the workpiece's position data.
The present value of the high-speed counter is stored in the Auxiliary Area and can be used as posi-
tion data. When it reaches preset values, interrupts can be generated. The count can be started and
stopped. Depending on the instruction, the frequency (speed) can be read from the present value of
the high-speed counter.
Encoder
Phases A/B
Increment/decrement pulse input
Reset (phase Z) input
Etc.
7-2
Changes the PV.
Counter
High-speed counter PV
input (stored in Auxiliary Area)
Read
High-speed counter
comparison
Target value
Range comparison
upper/lower limits
Setting
• Setting target values or range
upper/lower limits, and starting
comparison and specifying the interrupt
task to be started
• Reading PV (from Auxiliary Area or
Read
using PRV(881) instruction)
• Reading frequency (using PRV
instruction)
Interrupt task
CTBL
CJ2M CPU Unit Pulse I/O Module User's Manual
PRV