GL300 @Tracker Air Interface Protocol
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+GTQSS
or
AT+GTSRI
command.
+ACK:GTHBD:
Example:
+ACK:GTHBD,1A0102,135790246811220,,20100214093254,11F0$
Parameter
Length (byte)
Range/Format
Default
Protocol version
6
XX0000 – XXFFFF,
X
∈
{'A'-'Z','0'-'9'}
Unique ID
15
IMEI
Device name
20
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,1A0102,11F0$
Parameter
Length (byte)
Range/Format
Default
Protocol version
6
XX0000 – XXFFFF,
X
∈
{'A'-'Z','0'-'9'}
Count number
4
0000 – FFFF
Tail character
1
$
$
<
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.
3.5.
Sever Acknowledgement
If server acknowledgement is enabled by AT+GTQSS or AT+GTSRI command, the backend
server should reply to the device whenever it receives a message from the device.
+SACK:
Example:
+SACK:11F0$
Parameter
Length (byte)
Range/Format
Default
TRACGL300AN001
- 85 -
Queclink
Confidential