Specifications

CPU and Input/Output Configuration
6-6
S7-200 Programmable Controller System Manual
C79000-G7076-C233-01
A block diagram of the digital input circuit is shown in Figure 6-5.
Optical
isolation
Digital input
filter
Pulse catch
function
Pulse catch
enable
External
digital input
Input to CPU
Figure 6-5 Digital Input Circuit
The response of an enabled pulse catch circuit to various input conditions is shown
in Figure 6-6.
Input
Pulse catch
Input
Input
Input update Input update
CPU scan n+1CPU scan n
Time
enabled
Pulse catch
enabled
Pulse catch
enabled
Figure 6-6 Pulse Catch Example