Clock Synchronicity - Siemens SIMATIC S7-400 Configuration And Use Manual

CPUs of the S7-400
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Clock Synchronicity

Introduction
Clock synchronicity is the synchronous coupling of the signal detection and signal
output via the distributed I/O and the program execution to the PROFIBUS clock
pulse.
Clock synchronicity is not available with the CPUs of the S7-400H.
Advantages
Clock synchronicity offers the following advantages:
• The input data are always read in the same intervals and the output data are
always generated in the same intervals.
• All input and output data are transmitted in a consistent manner. All the data in
the process image belong together in both a logical and a chronological sense.
• The user program, the acquisition of the input data and the generation of output
data are synchronized. The process reaction times are therefore always the
same.
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Automation System S7-400 Configuration and Use
A5E00442711-02