System Information; Redundant Function - Mitsubishi Electric MELSEC iQ-R Series User Manual

System information

The following is the list of special register areas relating to the system information.
No. Name
SD1622 Process CPU operation
mode

Redundant function

The following is the list of special register areas relating to the redundant function.
No. Name
SD1642 BACKUP/SEPARATE
LED flashing cause
SD1643 System switching cause
Data stored Details
Process CPU operation This register stores the operation mode of the Process CPU
mode 80H: Process mode
81H: Redundant mode
Data stored Details
BACKUP/SEPARATE Flashing cause of BACKUP/SEPARATE LED is stored using the
LED flashing cause following bit pattern.
b15b14
Corresponding bits to each cause turns on.
b1: Tracking communications disabled
b3: Stop error of the standby system
b4: Operating status mismatch between both systems
b5: Memory copy being executed
b6: Online change being executed
b7: A failure of a network module detected on the standby
system
b8: System switching being executed
b9: A redundant function module being changed online
b10: System switching disabled on the standby system by using
the DCONTSW instruction
b11: Online module change being executed on a main base unit in
a redundant system with redundant extension base unit
• 0 is stored as initial value.
• When the multiple causes occurred at the same time, bits
corresponding to each cause turn on simultaneously. If the
tracking communications are disabled or the redundant function
module is being changed online, the other causes turn off.
• When the redundant function module in the other system is being
changed online, "Tracking communications disabled" is stored in
own system.
• Even if a cause of the system switching failure has occurred, the
system is switched when the system switching causes which
have higher priority, such as power-off or reset of the CPU
module, have occurred. ( Page 381 Execution availability of
system switching)
System switching cause Stores the system switching cause occurred in own system. The
occurred in own system system switching cause is stored in this register even if the systems
(normal/abnormal cannot be switched by a cause of system switching failure. This
systems witching) register is initialized with 0 when the CPU module is powered off
and on or is reset.
0: Initial value (the control system never been switched)
1: Power-off, reset, hardware failure
2: Stop error
3: System switching request from a network module
16: System switching request by using the SP.CONTSW instruction
17: System switching request using an engineering tool
When the system is switched upon the power-off or reset of the
CPU module in the control system, 1 is not stored in SD1643 of the
new standby system.
b12 b11 b10 b9 b8 b7 b6 b5 b4 b3 b2
Appendix 5 List of Special Register Areas
Set by (setting
timing)
S (Initial)
Set by (setting
timing)
S (Status change)
b1 b0
S (At system
switching)
APPX
701
A