title: Meitrack device what to return to confirm server recived data
body: <p>I am communicating with a meitrack odb device, i can receive data but when i set the protocol to"Event report needs servers confiramtion " i get and extra field (i resume this is the cache count". In the documentation i can only find "AFF" to return to the device, this doesnt seem to clear the cache though.</p>
  
  <p>***Deleting a GPRS Event In the Cache Zone – AFF
  GPRS Setting    AFF, Number of deleted GPRS events
  GPRS Responding AFF, Number of remaining caches,Command type, (-) Latitude,(-) Longitude,Data and</p>
  
  <pre><code>time,Status,Number of satellites,GSM signal status,Speed,Direction,Horizontal positioning accuracy,Altitude,Mileage,Run time,Base station information,I/O port
  </code></pre>
  
  <p>status,Analog input value
  Description Number of deleted GPRS events: hexadecimal string. The default value is 1.
  Number  of  remaining  caches:  total  number  of  events  in  internal  flash  memory. Hexadecimal string.
  Applicable Model    All
  Example
  GPRS Sending    @@h27,353358017784062,AFF,1*0B\r\n
  GPRS Receiving  $$h28,353358017784062,AFF,OK*3D\r\n</p>