Siemens SIMATIC ET 200AL - Time Behavior of Standard Technology; Time Behavior of Time-Based IO

Time-based IO basics
2.2 Time behavior of Time-based IO
High-precision input/output with Time-based IO
14 Function Manual, 08/2014, A5E33454822-AB
2.2
Time behavior of Time-based IO
2.2.1
Time behavior of standard technology
The time behavior of the inputs/outputs depends on the following factors for standard
technology:
● CPU program (program structure)
● Bus cycle times (fieldbus, backplane bus)
● Cycle time of the I/O modules
● Internal cycle time of sensors/actuators
A deterministic statement as to
● when an input event (e.g., sensor signal) has taken place
● when the output event has an effect on the input event (e.g., output switches)
will become inaccurate due to the time factors listed above.