5
5.3 The System Switching Function
5.3.5 Special Relays/Registers For System Switching
5
- 54
1
OV
ER
VIE
W
2
SYS
TEM
CONFIGURA
TI
ON
3
TR
AC
KI
N
G
C
ABL
E
4
P
R
OCE
DURE
FO
R
S
TAR
TING
UP
A
RE
DUN
DAN
T
S
Y
S
T
E
M
5
RE
DUNDA
NT S
Y
S
T
E
M
FUNCTIONS
6
RE
DUN
DAN
T
S
Y
S
T
E
M
NE
TW
O
R
K
S
7
PR
OG
R
A
MM
IN
G
CA
UTIO
N
S
8
TR
O
U
BLE
S
HOOTING
Set, – Not set
Table5.39 Special Registers For System Switching (Continued)
Device
No.
Name
Description
Setting at Time of System Switching
New Control System
CPU Module
New Standby
System CPU Module
SD1588
System Switching
Condition
Stores system switching condition that occurred on that system.
Stores system switching condition even when system cannot switch due to
system switching disenabling condition.
Initializes at 0 at power ON / reset
clear
0: Initial value (system switching has not yet occurred)
1: Hardware failure, watchdog timer error
2: Stop error (except watchdog time error)
3: System switching request from network module
16: System switching instruction
17: System switching request from GX Developer
–
SD1589
System Switching
Disenabling
Condition
When system switching occurs due to a system switching condition, the
system switching disenabling condition when system switching could not be
performed is stored in the following values:
0: System switching completed successfully
1: Tracking cable malfunction (cable disconnection, cable malfunction or
internal circuit malfunction)
2: Hardware failure, power OFF, resetting or watchdog timer error occurring
on standby system
3: Hardware failure, power OFF, resetting or watchdog timer error occurring
on control system
4: Preparing for tracking communication
5: Communication timeout
6: Stop error on standby system (except watchdog timer error)
7: Operations on the 2 systems are different (detected only in Backup Mode)
8: Copying memory from control system to standby system
9: Writing during RUN
10: Detecting network fault on standby system
• Initializes at 0 at same system power ON
• Stores 0 when system switching completes successfully.
–
–
SD1590
Same System
Network Module
No. Issuing
System Switching
Request
• The following bits are turned ON for each same system module from which
a system switching request was issued.
• Turns OFF on system after user has removed the corresponding module
malfunction
• See SD1690 for the other system module No. issuing a system switching
request.
b1 b0
b15
b11
to
to
0
0/1
0/1
0
Module 0: Disabled because CPU
module is a 2-slot unit
Module 1: Module to the right of
CPU module
Module 11: In 12 Slot Base
(Q312B), the module farthest to
the right
SD1590
Each Bit / Bits
0 : OFF
1 : ON
