Technical data

Table Of Contents
Overview over the S7 Communication and the S7 Basic Communication
System Software for S7-300/400 System and Standard Functions - Volume 2/2
A5E00739858-01
20-5
In the S7-400 by contrast the communication data are not processed in the cycle
checkpoint, but in fixed time slices during the program cycle. The consistency of a
variable is ensured by the system.
These communication areas can then be accessed consistently using the
PUT/GET functions or reading/writing of variables, for example by an OP on an
OS.
Recommendation
For further information on data consistency, please refer to the information
describing individual blocks as well as the manual Communication with SIMATIC.