Standby System Output Setting - Mitsubishi Electric MELSEC iQ-R Series User Manual

Standby system output setting

Output timing
When "Standby System Output Setting" has been set to "Enable", the output timing from the standby system in backup mode
is at the completion of the END processing or depends on the refresh group setting or refresh settings of each module. (
Page 113 Group setting for refresh)
Therefore, when a control system execution program is set in the refresh group setting, 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 in backup mode, set "Both Systems Program
Executions Setting". ( Page 418 Program Execution in Both Systems)
Operation at system switching
The operation performed at 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".
Item
Output (Y)
Direct access output
(DY)
For the program execution in both systems, refer to the following.
Page 418 Program Execution in Both Systems
26 REDUNDANT FUNCTION
426
26.7 Redundant System Operation Setting
CPU module of the new control
system
The status of the old standby system is held
and output refresh is performed.
In the program execution after system
switching, data is output when an instruction
using the direct access output (DY) is
executed.
CPU module of the new standby system
The status of the old control system is held and output refresh is performed.
However, no data is output, although the output Y of the module mounted on the
extension base unit is held.
■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.
However, no data is output even when an instruction using the direct output of the
module mounted on the extension base unit is executed.
■For program executed in the control system
No operation is performed because the program does not operate.