Siemens SIMATIC 505 User Manual

Overview

Series 505 High Speed Counter 
and Encoder Module User

’s Manual

If input A leads input B, the module counts up on both the rising and
falling edges of input A. If input B leads input A, the module counts down
on the rising and falling edges of input A. 

Figure 1-6 illustrates the relationship between inputs A and B and the
count value in the 2X quadrature mode.

1

2

3

4

3

2

1

0

A

B

25



s

 min

Counts Up

(A Leading)

Counts Down

(B Leading)

Count Value

26.7 



s

min