Siemens Simatic S7-1500 - Special Instructions for S7-1500 R;H Redundant Systems; Disabling;Enabling SYNCUP with the RH_CTRL Instruction

Basics of program execution
10.4 Special instructions for S7-1500R/H redundant systems
S7-1500R/H redundant system
System Manual, 01/2024, A5E41814787-AF
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*Exception: In the RUN-Redundant system state, a higher-priority OB 83 "Pull/plug modules"
does not interrupt the execution of an OB 82 "Diagnostic interrupt".
Note
Communication
Communication (for example test functions with the PG/PC) always operates with a priority of
15. To avoid unnecessarily prolonging the program runtime in the case of
time-critical
applications, make sure that these OBs are not delayed or interrupted by communication.
Assign a priority > 15 for these OBs.
Reference
Additional information on organization blocks is available in the STEP 7 online help.
10.4 Special instructions for S7-1500R/H redundant systems
10.4.1 Disabling/enabling SYNCUP with the RH_CTRL instruction
Introduction
You use the "RH_CTRL" instruction to disable SYNCUP or to enable the execution of the
SYNCUP for the S7-1500R/H redundant system. The disable applies:
• Until you cancel it with the "RH_CTRL" instruction or
• Until the S7-1500R/H redundant system switches to the STOP system state
Figure 10-2 RH_CTRL instruction