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CHAPTER6 FUNCTIONS
1
2
3
4
5
6
7
8
6.11 Mo
nitor
Function
6.11.3
E
xter
nal input/ou
tput forced on
/off
(4) Precautions in a redundant system where the Redundant CPU is used
(a) CPU module for which forced on/off is registered or cancelled
In redundant systems, register or cancel forced on/off for the control system CPU module. (Forced on/off
cannot be registered or cancelled for the CPU modules in both systems individually.)
After the systems are switched, register or cancel forced on/off for the CPU module in the new control system
(the system that was switched from the standby system to the control system).
If forced on/off is registered or cancelled for the standby system CPU module, an error (error code: 4240
H
)
occurs.
(b) When the CPU modules are in separate mode
When the control system CPU module is powered off and then on or reset, the registered forced on/off is
cancelled.
Input and output operations of the CPU module after cancellation will be the same as those described for
"Forced on/off cancellation (no operation)" in Table6.13.
Note that the output operation of the module on the MELSECNET/H remote I/O station will be as follows.
1) While the CPU module is powered off or reset
The CPU module holds the output status in the control system.
2) When the CPU module is powered off and then on or reset
The CPU module outputs the results of sequence program operations. (Same operation for "Forced on/off
cancellation (no operation).)