Siemens Simatic S7-1500R System Manual page 202

Points to note
● All outputs are disabled or respond as configured for the given module: They provide a
configured substitute value or retain the last value output and switch the controlled
process to a safe operating state.
● The process image is initialized.
● The process image is not updated.
To read the current state of inputs during STARTUP, you can access inputs with direct
I/O access.
To initialize outputs during STARTUP, you can write values via the process image or with
direct I/O access. The values are output at the outputs during the transition to the RUN
operating state.
● The CPU always starts up in warm restart mode.
– If you define data as retentive, its content is retained beyond program startup after
– The non-retentive bit memories, timers and counters are initialized.
– The non-retentive tags in data blocks are initialized.
● During STARTUP, cycle time monitoring is not yet running.
● The CPU processes the startup OBs in the order of the startup OB numbers. The CPU
processes all programmed startup OBs regardless of the selected startup mode (see
figure below, "Setting the startup behavior").
● If a relevant event occurs, the CPU can start the following OBs in startup:
– OB 82: Diagnostics interrupt
– OB 83: Removal/insertion of 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)
The CPU does not start all other OBs until the transition to the RUN operating state.
Behavior when expected and actual configurations do not match
The configuration downloaded to the CPU is the expected configuration. The actual
configuration is the actual, physical configuration of the automation system. If the expected
configuration and actual configuration differ, the hardware compatibility setting defines the
behavior of the CPU.
S7-1500R/H redundant system
System Manual, 10/2018, A5E41814787-AA
STOP or a power failure.
You can find a description of how to use global and local error handling in the STEP 7
online help.
Commissioning
9.4 Operating and system states
201