Startup Operating State - Siemens SIMATIC S7-1500 System Manual
Redundant system
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Also See for SIMATIC S7-1500:
- Function manual (402 pages) ,
- System manual (393 pages) ,
- Manual (188 pages)
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The following table provides you with an overview of how the redundant system starts and at
the same time runs through the various operating modes and system states. The following
initial situation and steps are an example.
The operating and system states are described in detail in the following sections.
Table 12- 3
Redundant system startup
No. in
Primary CPU
diagram
Initial situation: Both CPUs are in STOP operating state. The mode selectors are also in the STOP position.
Step 1: Switch the mode selector of the CPU that is to be primary CPU from STOP to RUN.
①
The CPU switches to STARTUP and
executes startup OB 100 and
other available startup OBs.
②
Following successful STARTUP,
the CPU switches to RUN.
The CPU runs like a standard CPU
in RUN and executes the user
program.
Step 2: Switch the mode selector on the backup CPU from STOP to RUN.
③
RUN → RUN-Syncup
The two user programs are synchronized for redundant mode. The primary CPU copies the contents of the
load and work memory to the backup CPU. The backup CPU catches up with user program processing on the
primary CPU. After successful synchronization, the memory content is identical on the two CPUs.
④
RUN-Syncup → RUN-Redundant
After the SYNCUP CPUs go to RUN-Redundant mode. Both CPUs process the user program synchronously.
The state transition also triggers OB 72 and possibly OB 70. You can find more information on the OB 72 and
OB 70 in the section Programming the S7-1500R/H (Page 317).
12.4.2
STARTUP operating state
Startup processing (in the primary CPU only)
STARTUP is only executed by the primary CPU.
In STARTUP, the primary CPU behaves just like an S7-1500R/H standard CPU.
Response
Before the CPU starts to execute the cyclic user program, a startup program is executed.
By suitably programming startup OBs, you can initialize variable tags for your cyclic program
in the startup routine. You can program one or more startup OBs, or none at all.
S7-1500R/H redundant system
System Manual, 01/2024, A5E41814787-AF
System state
STOP → STARTUP
STARTUP → RUN-Solo
RUN-Solo → SYNCUP
SYNCUP → RUN-Redundant
Commissioning
12.4 Operating and system states
Backup CPU
The CPU remains in STOP mode.
The CPU remains in STOP mode.
STOP → SYNCUP
SYNCUP → RUN-Redundant
383
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