Mitsubishi Electric MELSEC iQ-R Series User Manual page 240

Behavior of forced on/off
This section describes the behavior of forced on/off in the following cases in redundant system.
■At operation mode change
Even if the operation mode has been changed (backup mode  separate mode, or separate mode  backup mode), the
forced on/off registration information before the change remains.
■At system switching
Even if a system switching is performed, the forced on/off registration information before the switching remains since forced
on/off registration information is transferred from the control system to the standby system.
■When the CPU module of only one system is powered off and on or is reset
Condition
Backup mode
Separate mode
■When tracking communications are disabled
When tracking communications with the standby system are disabled or the system is operating only with the control system,
forced on/off can be registered or registration of forced on/off can be canceled to the control system. Forced on/off registration
information of the control system is reflected to the standby system when tracking communications are enabled.
Checking the forced on/off execution status
The execution status of the forced on/off can be checked in the following ways.
■Engineering tool
The execution status can be checked with the [Update Status] button of the engineering tool. ( Page 234 Operation
method of forced on/off)
■FUNCTION LED
The FUNCTION LED of the CPU module flashes by registering forced on/off (every 200ms).
The display status of the FUNCTION LED can be checked with "Module Information List" in the module diagnostics. ( GX
Works3 Operating Manual)
■Special register
SD1488 (Debug function usage status) can be used to check whether the external input/output forced on/off function is used.
( Page 668 List of Special Register Areas)
19 TEST FUNCTION
238
19.1 External Input/Output Forced On/Off Function
Behavior
Control Although a system switching is performed, the forced on/off registration information of the new control system
system remains while the CPU module of the old control system is off or in the reset state. After the CPU module of the old
control system is powered on or is reset, the forced on/off registration information of the new control system is
reflected to the new standby system.
Standby The forced on/off registration information of the control system remains while the CPU module of the standby system
system is off or in the reset state. After the CPU module of the standby system is powered on or is reset, the forced on/off
registration information of the control system is reflected to the standby system.
Control The forced on/off registration information of the standby system remains while the CPU module of the control system
system is off or in the reset state. After the CPU module of the control system is powered on or is reset, the forced on/off
registration of the standby system is canceled in a batch and no forced on/off is registered in both systems.
Standby The forced on/off registration information of the control system remains while the CPU module of the standby system
system is off or in the reset state. After the CPU module of the standby system is powered on or is reset, the forced on/off
registration information of the control system is reflected to the standby system.