Mitsubishi Electric Melsec Q Series User Manual page 98

3
SPECIFICATIONS
3
- 57 3.4 Buffer Memory
3.4.14 Redundant system area
System switching is performed when an error occurs in communication with a DP-
Slave, which is specified in the System switching condition setting area
(Disconnected station detection) (Un\G23648 to Un\G23656).
POINT
(1) Set values into the System switching condition setting area (Disconnected
station detection) (Un\G23648 to Un\G23656) when the Data exchange start
request signal (Y00) is OFF.
Values set with the Data exchange start request signal (Y00) ON are ignored.
(2) With a communication error identified in a system switching target DP-Slave
after system switching, no system switching is performed even if a
communication error occurs in another DP-Slave.
To perform system switching again, restore all of the switching target DP-
*1
Slaves to normal condition.
The DP-Slave status can be confirmed in the Slave status area (Normal
communication detection) (Un\G23040 to Un\G23047). (
* 1 It is any of all the DP-Slaves that are specified in the System switching DP-Slave specification area
(Un\G23649 to Un\G23656).
Control system
New standby system
Power
Redundant
supply
CPU
module
Bus terminator
DP-Slave
(FDL address 2)
Communication
failure
New standby system
Power
Redundant
supply
CPU
module
Bus terminator
DP-Slave
(FDL address 2)
Communication
failure
Standby system
New control system
QJ71 Executes system
switching
PB92V
Tracking cable
DP-Slave
(FDL address 3)
Before recovery of the
switching target DP-Slave, an
error occurred at another DP-
Slave.
New control system
No system
QJ71
switching
PB92V
Tracking cable
DP-Slave
(FDL address 3)
Power
QJ71
Redundant
supply
CPU PB92V
module
DP-Slave
(FDL address 4)
Power
Redundant QJ71
supply
CPU PB92V
module
DP-Slave
(FDL address 4)
Communication
failure
*1
Section 3.4.5)