Moxa UC-8410A-T-LX [71/86] Wdt watch dog timer

UC-8410A Series Linux Software Programmer’s Guide

6-9

WDT (Watch Dog Timer)

The WDT works like a watch dog function. You can enable it or disable it. When the WDT is enabled, but the

application does not acknowledge it, the system will reboot. You can set the ack time from a minimum of 1 sec

to a maximum of 1 day. The default timer is 60seconds and the NO WAY OUT is enabled by default; there is no

way to disable the watchdog once it has been started. For this reason, if the watchdog daemon crashes, the

system will reboot after the timeout has passed.

Function WDIOC_KEEPALIVE

Description Writes to the watchdog device to keep the watchdog alive.

Usage int ioctl(fd, WDIOC_KEEPALIVE, 0)

Function WDIOC_SETTIMEOUT

Description Modifies the watchdog timeout

Min: 1second. Max: 1day; Default: 60seconds

Usage int timeout = 60;

ioctl(fd, WDIOC_SETTIMEOUT, &timeout);

Function WDIOC_GETTIMEOUT

Description Queries the current timeout

Usage int timeout;

ioctl(fd, WDIOC_GETTIMEOUT, &timeout);

Function WDIOC_GETSTATUS

Description Asks for the current status

Usage int flags;

ioctl(fd, WDIOC_GETSTATUS, &flags);

Function WDIOC_GETBOOTSTATUS

Description Asks for the status at the last reboot

Usage int flags;

ioctl(fd, WDIOC_GETBOOTSTATUS, &flags);

Function WDIOC_GETSUPPORT

Description Asks what the device can do

Usage struct watchdog_info ident;

ioctl(fd, WDIOC_GETSUPPORT, &ident);