Siemens SIMATIC ET 200SP System Manual page 183

● The startup OBs are executed in the order of the startup OB numbers. All startup OBs
that you have programmed are executed, regardless of the selected startup mode.
● The following OBs can be started during startup, if a corresponding event occurs:
– OB 82: Diagnostics interrupt
– OB 83: Pull/plug interrupt for modules
– OB 86: Rack error
– OB 121: Programming error (only for global error handling)
– OB 122: I/O access error (only for global error handling)
No other OBs can be started until after the transition to RUN mode.
Response when expected and actual configurations do not match
The configuration downloaded to the CPU represents the expected configuration. The actual
configuration is the actual configuration of the ET 200SP distributed I/O system. If the
expected configuration and the actual configuration do not match, the setting of the
"Comparison preset to actual configuration" parameter determines the reaction of the CPU
(see section Operating mode transitions (Page 186)).
Canceling a startup
If errors occur during startup, the CPU cancels the startup and returns to STOP mode.
The CPU does not execute a startup or cancels a startup under the following conditions:
● If no SIMATIC memory card is inserted or an invalid SIMATIC memory card is inserted.
● If no hardware configuration has been downloaded.
Distributed I/O system
System Manual, 12/2015, A5E03576849-AF
You can find a description of how to use global and local error handling in the STEP 7
online help.
Commissioning
10.6 Operating modes of the CPU
183