Table of Contents
Advertisement
Execution availability of system switching
The following tables show the execution availability of system switching in each operation mode.
In backup mode
: Switching possible, : Switching not possible
Redundant system status
Normal operation or continuation
error in the standby system
Tracking communications
disabled (cable disconnection)
Power-off, reset, hardware
failure of the standby system
CPU module
Stop error in
WDT error
the standby
Error other
system
than WDT
error
Network error detected in the
*1
standby system
During memory copy from
control system to standby
system
During online change
Mismatch between the CPU
module operating status of both
systems
During system switching
During online
Redundant
module
module
change
Other modules
System switching disabled by the
DCONTSW instruction
*1 When the group specification has been set in the standby system, a network error is not detected if communication is available with the
line of an Ethernet-equipped module after a communication error has occurred on the other Ethernet-equipped module. ( MELSEC
iQ-R Ethernet User's Manual (Application))
*2 After the online change has been completed, the switching cause is detected and the systems are switched. However, when an online
change is being executed only in the standby system, the systems cannot be switched.
*3 If system switching is disabled when a system switching request is sent, a continuation error occurs and a cause of a system switching
failure is stored in SD1644 (Cause of system switching failure).
*4 If system switching is disabled when a system switching request is sent, the error code corresponding to a cause of the system
switching failure is returned.
*5 When the systems are switched during an online change, a mismatch between the files is detected in the system consistency check and
a stop error may occur on the new standby system. ( Page 477 File)
*6 Although the control system CPU module is switched to the standby system CPU module, the existing standby system is not switched.
Execution availability of system switching
Automatic system switching
Power-off or
Hardware
Stop error of the CPU
reset of the
failure of
module
CPU
the CPU
WDT error
module
module
*6
*6
*6
*6
System
switching
request
Error other
from a
than WDT
network
error
module
*6
*6
*6
*6
*6
*2*5
*6
Manual system switching
System
System
switching
switching
request by
request
the
from the
SP.CONTSW
engineering
*3
*3
*4
instruction
tool
28 FUNCTIONS
28.2 System Switching
28
447
- Quick Links:
- Part 1 Cpu Module Operation
Hide quick links:
Advertisement
Table of Contents
