UC-7420/7410 User’s Manual

Programmer’s Guide

int swtd_close(int fd)

Description:

Close the file handle.

Input :

 

int fd

- the file handle from swtd_open() return value.

Output:

 

OK will be zero.

The other has some error, to get error code from errno().

4.Special Note

When you “kill the application with -9” or “kill without option” or “Ctrl+c” the kernel will change to auto ack the sWatchDog.

When your application enables the sWatchDog and does not ack, your application may have a logical error, or your application has made a core dump. The kernel will not change to auto ack. This can cause a serious problem, causing your system to reboot again and again.

5.User application example

Example 1:

#include<stdio.h> #include<stdlib.h> #include<string.h> #include<moxadevice.h>

int main(int argc, char *argv[])

{

int fd;

fd = swtd_open(); if ( fd < 0 ) {

printf(“Open sWatchDog device fail !\n”); exit(1);

}

swtd_enable(fd, 5000); // enable it and set it 5 seconds while ( 1 ) {

//do user application want to do

…..

….

swtd_ack(fd); …..

….

}

swtd_close(fd); exit(0);

}

The makefile is shown below:

all:

mxscaleb-gcc –o xxxx xxxx.c –lmoxalib

Example 2:

#include<stdio.h> #include<stdlib.h> #include<signal.h> #include<string.h>

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Moxa Technologies UC-7420/7410 user manual Special Note, User application example Example