User's Manual

Nordic ID PL3000 user manual, v. 2.6, October 2006 70

6.5.33 LinkWatchdog

Introduction

A common problem with many Wireless applications is that the network connection may be lost without

it becoming immediately apparent. More importantly, there may not be any straightforward way to re-

establish a lost network link. It is also not something that the end user should have to deal with. To solve

this problem the LinkWatchdog solution was created. It basically works by periodically checking that it

is able to access one or more predeﬁ ned servers. If it is unable to do this, it will attempt to restart the

network connection in order to re-establish it. The solution is made up of three components; there is the

LWD service which actually monitors the link status, there is a Control Panel applet for conﬁ guring the

LinkWatchdog and ﬁ nally a user interface program that is run by the LWD service when the connection is

lost.

The Control Panel Applet

Conﬁ guration and Control over the LWD service is done trough its control panel applet. The applet is

divided into four pages. The ﬁ rst one is for enabling / disabling the service and conﬁ guring it, the second

two are for conﬁ guring the user interface executable. The last page is for viewing and saving the LWD

service log.

Page 1 : Service Conﬁ guration

Before conﬁ guring the LinkWatchdog, you need

to enable it by checking the “Enable IP Address

Watchdog”. When the dialog box is closed, this

checkbox is used to determine if the LWD service

should be started or stopped.