Specifications

GMT00 @Track Air Interface Protocol
TRACGMT100AN001 – 106 –
3.4. Heartbeat
Heartbeat is used to maintain the contact between the device and the backend server if
communicating via GPRS. The heartbeat package is sent to the backend server at the interval
defined by <Heartbeat interval> in AT+GTSRI command.
 +ACK:GTHBD
Example:
+ACK:GTHBD,080100,135790246811220,,20100214093254,11F0$
Parameter
Length(byte)
Range/Format
Default
Protocol version
6
XX0000 – XXFFFF,
X∈{'A' – 'Z','0' – '9'}
Unique ID
15
IMEI
Device Name
<=10
'0' – '9' 'a' – 'z' 'A' – 'Z'
Send Time
14
YYYYMMDDHHMMSS
Count Number
4
0000 – FFFF
Tail Character
1
$
$
Whenever the backend server receives a heartbeat package, it should reply an acknowledgement to
the device.
 +SACK:GTHBD
Example:
+SACK:GTHBD,080100,11F0$
+SACK:GTHBD,,11F0$
Parameter
Length(byte)
Range/Format
Default
Protocol version
6
XX0000 – XXFFFF,
X∈{'A' – 'Z','0' – '9'}
Count Number
4
0000 – FFFF
Tail Character
1
$
$
 <Protocol Version>: The device type and the protocol version that the backend server
supported. This field is optional. The backend server could just send an empty field to
decrease the length of the heartbeat data acknowledgement.
 <Count Number>: The backend server uses the <Count Number> extracted from the
heartbeat package from the device as the <Count Number> in the server acknowledgement of
the heartbeat.
Queclink
Confidential