Siemens SIMATIC 505 Counting Modes (continued)

Overview
1-10
Series 505 High Speed Counter
and Encoder Module User ’ s Manual
Counting Modes (continued)
1.5.5
4X
Quadratur e If input A leads input B, the module counts up on rising and falling edges
of both input A and input B. If input B leads input A, the module counts
down on the rising and falling edges of input A and input B.
Figure 1-7 shows the relationship between inputs A and B and the count
value in the 4X quadrature mode.
4X Quadrature
12 34 5 6 7 8 7 65 4 32 1 0
A
B
25s
min
Counts Up
(A Leading)
Count V alue
Counts Down
(B Leading)
26.7 s
min
Figure 1-7 4X Quadrature Mode