Mitsubishi Electric MELSEC iQ-R-R04CPU - Execution Availability of System Switching

616
37 FUNCTIONS
37.1 System Switching
Execution availability of system switching
The following tables show the execution availability of system switching.
: Switching possible, : Switching not possible
*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 system 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 the cause of the 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 the 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 644 File)
*6 Although the control system CPU module is switched to the standby system CPU module, the existing standby system is not switched.
*7 The initial processing of the safety function after system switching completes is also included.
Status of system using the
SIL2 Process CPU
Execution availability of system switching
Automatic system switching Manual system switching
Power-off or
reset of the
CPU
module
Hardware
failure of
the CPU
module
Stop error of the CPU
module
System
switching
request
from a
network
module
*3
System
switching
request by
the
SP.CONTSW
instruction
*3
System
switching
request
from the
engineering
tool
*4
WDT error Error other
than WDT
error
Normal operation or continuation
error in the standby system
 
Tracking communications
disabled (cable disconnection)

*6

*6
 
Power-off, reset, hardware
failure of the standby system
CPU module

*6

*6
 
Stop error in
the standby
system
WDT error 
*6

*6
 
Error other
than WDT
error

*6
 
Network error detected in the
standby system
*1
 
During memory copy from
control system to standby
system

*6
 
During online change 
*2*5

Mismatch between the CPU
module operating status of both
systems
 
Mismatch between the safety
operation mode of both systems
 
Error in safety tracking data
detected

*6

*6
 
During system switching
*7
 
During online
module
change
Redundant
function
module

*6

*6
 
Other modules  
System switching disabled by the
DCONTSW instruction
 