S7-1500R/H redundant system
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System Manual, 10/2018, A5E41814787-AA
Basics of program execution
7
7.1
Programming the S7-1500R/H
User program for the S7-1500R/H redundant system
For the design and programming of the user program, the same rules apply for the
redundant S7-1500R/H system as for the S7-1500 automation system.
The user program is stored identically in both CPUs in redundant operation. Both CPUs
process the user program event-synchronously.
From the point of view of user program execution, the S7-1500R/H redundant system
behaves like the S7-1500 automation system. Synchronization is integrated into the
operating system and runs automatically and hidden between the primary and backup CPU.
Specific instructions and blocks for the S7-1500R/H redundant system
Specific instructions and OBs are available for the S7-1500R/H redundant system.
The "RH_CTRL" instruction is used to disable SYNCUP or to enable the running of the
SYNCUP. The goal is to only permit the SYNCUP in less critical process phases (see
Disabling/enabling SYNCUP with the RH_CTRL instruction (Page 157)).
You use the instruction "RH_GetPrimaryID" in the user program to read out which CPU is
currently the primary CPU (see Determining the primary CPU with "RH_GetPrimaryID"
(Page 160)).
In addition to the OBs of the S7-1500 CPU, you can also use OB 72 (CPU redundancy
error). OB 72 is called when the S7-1500R/H redundant system has reached or left the RUN-
Redundant system state.
Summary of Contents for Simatic S7-1500H
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