CPU 31xC and CPU 31x, Technical Data 
Manual, 01/2006 Edition, A5E00105475-06 
5-1 
Cycle and reaction times 
5
5.1  5.1 Overview 
Overview 
This section contains detailed information about the following topics: 
•  Cycle time 
•  Reaction time 
•  Interrupt response time 
•  Sample calculations 
Reference: Cycle time 
You can view the cycle time of your user program on the PG. For further information, refer to 
the 
STEP 7 Online Help
, or to the 
Configuring Hardware and Connections in STEP 7
 Manual 
Reference: Execution time 
can be found in the 
S7-300 Instruction List for CPUs 31xC and 31x
. This tabular list contains 
the execution times for all 
•  STEP 7 instructions the relevant CPU can execute, 
•  the SFCs / SFBs integrated in the CPUs, 
•  the IEC functions which can be called in STEP 7. 
5.2  5.2 Cycle time 
5.2.1  Overview 
Introduction 
This section explains what we mean by the term "cycle time", what it consists of, and how 
you can calculate it.