Mitsubishi Electric Melsec Q Series User Manual page 146

4
FUNCTIONS
4
- 37 4.8 Redundant system support function
3) DP-Slave output status when the CPUs in the control and standby systems are
stopped
Communication of the QJ71PB92V is stopped.
Since the communication is stopped, a watchdog timer error may occur in the
DP-Slaves for which a watchdog timer is set, and their outputs may be turned
OFF.
The following table lists measures to hold outputs from DP-Slaves.
Table4.14 Measures to hold outputs from DP-Slaves
Item
When DP-Slave has no
Hold/Clear function for
output data
When DP-Slave has
Hold/Clear function for
output data
POINT
Whether or not output data are output from each DP-Slave to external devices
after stop of I/O data exchange differs depending on the DP-Slave setting.
For details, refer to the manual for the DP-Slave.
Disable the watchdog timer for the DP-Slave. (The watchdog timers of all
DP-Slaves are batch-disabled.)
Even if the Hold/Clear selection for output data is not allowed for the DP-
Slave, its output can be held.
Example) Watchdog timer setting example
Uncheck
the checkbox
Set the Clear/Hold setting for output data to "Hold" for the DP-Slave.
Output data can be held with the DP-Slave's watchdog timer enabled.
Example) Hold/Clear setting of output Data (for ST1Y2-TE2)
Set it to Hold
Description