Run Mode; Operating Mode Transitions - Siemens SIMATIC ET 200SP System Manual

Commissioning
11.6 Operating modes of the CPU
11.6.3

RUN mode

Behavior
In "RUN" mode the cyclic, time-driven, and interrupt-driven program is executed. Addresses
that are in the "Automatic Update" process image are automatically updated in each program
cycle. See also the section Process images and process image partitions (Page 139).
Execution of the user program
Once the CPU has read the inputs, the cyclic program is executed from the first instruction to
the last instruction.
If you have configured a minimum cycle time, the CPU will not end the cycle until this
minimum cycle time is finished even if the user program is completed sooner.
A cycle monitoring time is set to ensure that the cyclic program is completed within a
specified time. You can change the cycle monitoring time to suit your requirements. If the
cyclic program has not finished running within this time, the system responds with a time
error.
Further events such as hardware interrupts and diagnostics interrupts can interrupt the cyclic
program flow and prolong the cycle time.
Reference
Further information about cycle and response times is available in the Function Manual
Cycle and response times (http://support.automation.siemens.com/WW/view/en/59193558).
11.6.4

Operating mode transitions

Operating modes and operating mode transitions
The following figure shows the operating modes and the operating mode transitions:
Figure 11-9
210
Operating modes and operating mode transitions
Distributed I/O system
System Manual, 09/2019, A5E03576849-AJ