System A/B Settings - Mitsubishi Electric MELSEC iQ-R-R00CPU User Manual

27.5

System A/B Settings

Set the system A or B with the engineering tool and write the system settings to the CPU module.
[Online]  [Redundant PLC Operation]  [System A/B Setting]
Configuration procedure
*1 If the system A/B settings are set to the Process CPU that is not running in the redundant mode, the SYS A LED or SYS B LED of the
redundant function module will turn off. Follow the procedure below (writing data to the programmable controller).
Besides the method that uses the engineering tool for setting system A and B, system A and B can be
automatically set by using the systems.
When one system is set to system A and gets ready for tracking communications, the other system is
automatically set to system B, and vice versa.
For the system to which system A or system B has been assigned automatically, the system setting will be
overwritten automatically. In that case, the system setting change can be checked in the event history. (Event
code: 00700)
• If a system that has no system A/B setting yet is connected to the system specified as system A, the system
that has no system A/B setting will be automatically set to system B. (This event is not recorded in the event
history.)
• If a system specified as system A is connected to another system specified as system A, the system that is
turned off and on or reset will be automatically set to system B. (This event is recorded in the event history.)
1.
Set the CPU module to the STOP state.
2.
Select the setting to be written to own on the "System A/
B Setting" window.
3.
Click the [Execute] button.
4.
Click the [Yes] button on the window on the left. Check
that the SYS A LED or SYS B LED of the redundant
function module flashes in accordance with the setting.
5.
To change the system A/B settings, power off and on the
system or reset the CPU module, and then click the
[OK] button. Check that the SYS A LED or SYS B LED
of the redundant function module turns on in
accordance with the new setting.
27 PROCEDURE FOR STARTING UP A REDUNDANT SYSTEM
*1
431
27.5 System A/B Settings
27