37 FUNCTIONS
37.6 Redundant System Operation Setting
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37
Standby system output setting
Output timing
When "Standby System Output Setting" has been set to "Enable", the output timing from the standby system is at the
completion of the END processing or depends on the refresh group setting or refresh settings of each module. ( Page 65
Group setting for refresh)
Therefore, when a program set in the refresh group setting is a program executed in the control system, the I/O refresh is not
performed while the module is running because the program is not executed in the standby system. (When the CPU module
is in the STOP/PAUSE state, the I/O refresh is performed at the timing of the END processing.)
To execute a program set in the refresh group setting in the standby system, set "Both Systems Program Executions Setting".
( Page 647 Program Execution in Both Systems)
Operation at system switching
The operation performed at the system switching differs when "Standby System Output Setting" is set to "Enable". The
following table shows the operation performed when "Standby System Output Setting" has been set to "Enable".
For the program execution in both systems, refer to the following.
Page 647 Program Execution in Both Systems
Item New control system CPU module New standby system CPU module
Output (Y) The status of the old standby system is held and output
refresh is performed.
The status of the old control system is held and output refresh
is performed.
Direct access output (DY) In the program execution after system switching, data is
output when an instruction using the direct access output (DY)
is executed.
■For program executed in both systems
In the program execution after system switching, data is
output when an instruction using the direct access output (DY)
is executed.
■For program executed in the control system
No operation is performed because the program does not
operate.
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