7-19
7 High-speed Counters
CJ2M CPU Unit Pulse I/O Module User’s Manual
7-2 High-speed Counter Inputs
7
7-2-7 Reading the Count Direction
• Measuring Total Number of Revolutions
Precautions for Correct UsePrecautions for Correct Use
Measuring the rotational speed or total number of revolutions can be performed with high-speed
counter 0 only.
The count direction of a high-speed counter that was stored during the I/O refresh can be read from the
Auxiliary Area.
The PV that is stored in the following words can be read using the MOVL(498) instruction or other
instructions.
7-2-7 Reading the Count Direction
Reading the PV Refreshed at the I/O Refresh Timing
Pulse I/O
Module No.
Read value Auxiliary Area bit
0 (on the right) High-speed Counter 0 Count
Direction
A274.10 OFF: Decrementing
ON: Incrementing
High-speed Counter 1 Count
Direction
A275.10
1 (on the left) High-speed Counter 2 Count
Direction
A320.10
High-speed Counter 3 Count
Direction
A321.10
Execution condition
@PRV2
#0001
#03E8
D100
C2: Pulses per revolution, Example: 1,000 pulses (03E8 hex)
C1: Control data, Example: Converting counter PV to total number of revolutions
D: First destination word
D100
D101
Total number of revolutions that was read (r/min)
Conversion result
(lower word)
Conversion result
(upper word)