Allen-Bradley 2080-IF4 - Page 38

30 Rockwell Automation Publication 2080-UM004C-EN-E - March 2015
Appendix 4 High Speed Counter – 2080-MOT-HSC
Quadrature Counting
Quadrature X4 Counter
Counter shall increment or decrement on each edge of the A and B pulses when
the signal is in the positive or negative direction respectively. See previous
illustration.
Quadrature X2 Counter
The counter increments or decrements on each edge of the A pulse when the
signal is in the positive or negative direction respectively. See previous illustration.
Down Counter
Pulses on A will cause the down counter (Counter 0). Also pulses on B will cause
the down counter (Counter 1).
INPUT A
INPUT B
INPUT Z
Quadrature
Encoder
A
B
X1
Count
X2
Count
1
2
3
4
5
6
7
8
9
10
11
12
11
10
9
8
7
6
5
4
3
2
1
0