http://www.dagamagps.com/manual/T-102.pdf I sell these on trademe username petermcg
The above link is the manual which should give you an outline of what we are setting up. The Tracking System could be for example hard wired into a car,, you install a sim card into the unit, and then by dialing into it ,,it will return the GPS co ordinates that you can input into google maps and locate your Item.

Fault:
 Hi Peter,

Let me elaborate further:-

As for the new sim card, I had tried on a mobile phone to receive and send messages, it works perfect and messages all able to be read. This setting also had changed to GSM only too. Works perfectly.

When insert to the tracker, by using several different mobile phone set, all messages received from the cell phone number in the tracker stated "empty". So, I open up the message ..... there isnt any message at all.

So, I used a O2 PDA mobile phone to tried out to see if it work, therefore, I received the message as "The contents of this message cannot be displayed". 

As the sim card in the tracker was tested on mobile phone before inserting into it, it works perfectly. It is when the sim card in the tracker, empty or no message in it was received. 

I dun think its in chinese language as I also tried to switch to chinese language, the message is also empty.

Regards,

Can any one help, would anyone like to have a play with one of these,
Peter McGuire
petermcguire@mail.com