Siemens SIMATIC ET 200S Operating Instructions Manual page 110

1Count24V
2.10 Evaluation of count and direction signal
Double Evaluation
Double evaluation means that the positive and negative edge of the A signal are evaluated.
Whether up or down count pulses are generated depends on the level of the B signal.
The diagram below illustrates the double evaluation of the signals.
Figure 2-47
Quadruple Evaluation
Quadruple evaluation means that the positive and negative edges of the A and B signals are
evaluated. Whether up or down count pulses are generated depends on the levels of the A
and B signals.
The diagram below illustrates the quadruple evaluation of the signals.
Figure 2-48
Note
A counting frequency of 100 kHz refers to the maximum frequency of the A and B signals.
With double evaluation, a maximum frequency of 200 kHz is produced for the counting
pulses; with quadruple evaluation, the maximum frequency is 400 kHz.
110
Double Evaluation
Quadruple Evaluation
Technological Functions
Operating Instructions, 06/2010, A5E00124867-07