Hitachi HF-W7500 40, Руководство пользователя

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6. LIBRARY FUNCTIONS
6-7
Figure 6-1 Behavior of the WDTTO Contact
Dotted lines in Figure 6-1 denote the respective states of the contact and the thick line denotes
the transition of the state of the contact.
Figure 6-2 shows an example of the behavior of the WDTTO contact when the OS shuts
down. In this example, the timeout of the watchdog timer is 60 seconds. The process that
retriggers the watchdog timer terminates during shutdown and consequently the watchdog
timer times out.
Figure 6-2 Behavior of the WDTTO Contact (When the OS Shuts Down)
Dotted lines in Figure 6-2 denote the respective states of the contact and the thick line denotes
the transition of the state of the contact.
NOTE
In the explanation above, it is assumed that the RAS external contacts interface
is HJ-7805-21. If you use HJ-7805-22 as a RAS external contacts interface, the
behavior of the contact is opposite. This contact is open when the contact in the
explanation above is closed and the other way around.
OS shutdown starts. WDT is retriggered.
WDT is
retriggered.
WDT is retriggered.
60 seconds
Power is turned off.
Contact closed
(WDT has timed out.)
Contact open
(Normal)
WDT times out.
Time →
Power is
turned on.
OS startup
WDT is retriggered.
WdtControl function is called.
(Timeout: 10 seconds)
WDT stops.
WdtControl function is called.
WDT has stopped.
Power is turned off.
Contact closed
(WDT has timed out.)
Contact open
(Normal)
WDT times out.
Time →
10 seconds
WDT is
retriggered.
WDT is retriggered.