Mitsubishi Electric Q26UD(E)HCPU User Manual page 583

Number Name Meaning
Reason(s) for
Reason(s) system
SD1588 for system switching that
switching occurred in
host station
Reason(s)
Reason(s) for
for system
system
SD1589 switching
switching
failure
failure No
conditions
Network
Network
module
module head
head
address,
address,
SD1590 which
which
requested
requested
system
system
switching
switching
Memory Memory copy
SD1595 copy target target I/O
I/O number number
Memory Memory copy
SD1596
copy status status
*1 The information of the host CPU module is stored.
Explanation
The reason(s) for system switching on the host system is
stored. The following values are stored corresponding to the
methods for system switching: This register is initialized with
zero (0) stored when the system is powered on from off or is
reset.
0: Initial value (control system has never been switched)
1: Power off, Reset, H/W failure, WDT error
2: CPU stop error (except WDT)
3: System switching request from network module
16: Control system switching instruction
17: System switching request from a programming tool
• When a system switching has failed, a value
corresponding to the system switching failure cause is
stored.
0: System switching complete (default)
1: Tracking cable is not connected, tracking cable failure,
or internal circuit failure
2: H/W failure, power-off, reset, watchdog timer error on
the standby system
3: H/W failure, power-off, reset, WDT error on the control
system
4: Preparing tracking communication
5: Communication timeout
6: Stop error on the standby system (except for watchdog
timer error)
7: Operation differs between both systems (detected only
in the back up mode)
8: During memory copy from control system to standby
system
9: Performing program online change
10: Detecting a failure of network module on the standby
system
11: System is being switched
• The value is reset to "0" when host system is powered on.
• Zero is stored in this register upon completion of system
switching.
• When system switching is requested from a network
module in the host system, the bit corresponding to the
module that received the request turns on.
b11 b1 b0
b1 to b11: Slot No.1 to slot No.11 (Slot No.0 (b0) is invalid
because the CPU module occupies two slots.)
• The system turns off the bit after the error is removed by a
user.
• For the number for modules where system switching is
requested from a network module in other system, refer to
SD1690.
• Before SM1595 is turned from off to on, the I/O No. of the
memory copy destination (Standby system CPU module:
3D1 ) is stored.
H
• The execution result of the memory copy function is stored.
0: Memory copy is complete
4241 : Standby system power supply off
H
4242 : Tracking cable is disconnected or is damaged
H
4247 : Memory copy is being executed
H
4248 : Unsupported memory copy destination I/O number
H
APPENDICES
Corresponding
Set by Corresponding
ACPU
(When Set)
D9
S (when

condition
occurs)
S (when

system is
switched)
S
(Error/Status New
change)
U New
S (Status
New
change)
A
CPU
QnPRH
QnPRH
QnPRH
QnPRH
QnPRH
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