Mitsubishi Electric MELSEC iQ-R Series User Manual page 704

No. Name
SD1644 Cause of system
switching failure
SD1645 System switching request
status from a network
module of own system
SD1646 System switching request
status from a network
module of the other
system
SD1648 Cause of the other system
monitoring error
APPX
702
Appendix 5 List of Special Register Areas
Data stored Details
Cause number of system • If a system switching is failed because a cause of system
switching failure switching failure has occurred, either of the following values is
stored in this register.
0: System switching completed normally (default)
1: Tracking communications disabled
2: Tracking communication timeout
3: Stop error of the standby system
4: Operating status mismatch between both systems
5: Memory copy being executed
6: Online change being executed
7: A failure of a network module detected on the standby system
8: System switching being executed
9: A redundant function module being changed online or restarted
10: System switching disabled on the standby system by using the
DCONTSW instruction
11: Online module change being executed on a main base unit in a
redundant system with redundant extension base unit
• This register is initialized with 0 when own system is powered on.
• Zero is stored in this register upon completion of system
switching.
System switching request • The system switching request status from a network module of
status from a network the own system is stored using the following bit pattern. (The bits
module of own system of the positions where no modules are mounted turn off.)
b0 to b11: Slot No.0 to slot No.11
• The system turns off the bit after the error in the corresponding
module is removed by a user.
• For the system switching request status from a network module
of the other system, refer to SD1646.
System switching request • The system switching request status from a network module of
status from a network the other system is stored using the following bit pattern. (The
module of the other bits of the positions where no modules are mounted turn off.)
system
b0 to b11: Slot No.0 to slot No.11
• The system turns off the bit after the error in the corresponding
module is removed by a user.
• For the system switching request status from a network module
of the own system, refer to SD1645.
Cause of the other system • When an error has occurred on the communications with the
monitoring error other system during an initial processing (including when the
system is determined while waiting for the other system starts
up) or an END processing, either of the following bits turns on.
Once the error is cleared, the bit turns off.
b15
b0:
b1:
b2:
b15: Communications with the other system disabled (a redundant
• If either of b0, b1, b2 or b15 is on, the other bits are off.
• When the communications with the other system is disabled at
an initial processing (including when the other system is powered
off), b0 turns on. (When power-off or reset of the CPU module in
the other system is recognized, b1 turns on.)
• The tracking cable status of when one of the above mentioned
bits of this register is on can be checked in SD1755.
b11 ∙∙∙
b0
∙∙∙
b11 b0
b2 b1
b0
Communications with the other system disabled (other than a
redundant function module hardware failure in own system)
Power-off, reset, or hardware failure (the CPU module or the
redundant function module) in the other system
Stop error in the other system
function module hardware failure in own system)
Set by (setting
timing)
S (At system
switching)
S (Error/Status
change)
S (Every END)
S (Initial/every
END)/system
switching