MEITRACK T622 GPRS Protocol
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5.
The CCB command works with the CCC 0x0501 compression format. When the
tracker connects to the platform, the platform will send the CCB command or the
tracker responds using the CCB command. It means that the tracker will upload
data in CCC 0x0501 compression format and the data will include some
parameters in the CCB command.
6.
CCB customized parameters are a part of CCC parameters. CCB data with multiple
bytes is in little-endian format.
Applicable Model
T622
Example
GPRS Sending
CCB,Wheel based speed/1/2/2/Cluth switch/1/0/…/Engine temperature/2/0
GPRS Reply
CCB,ok
3.45
Setting the Data Compression Format – CCC
GPRS Sending
CCC,
Quantity of deleted data
GPRS Reply
CCC,<
AAA compression protocol version
><
AAA longitude and latitude packet
length
><
Number of remaining cache
><
AAA longitude and latitude packet 1
>……<
AAA
longitude and latitude packet n
>
Description
1.
AAA compression protocol version: contains 2 bytes; hexadecimal; little-endian.
2.
AAA longitude and latitude packet length: indicates the packet length of the
specific protocol version; contains 2 bytes; hexadecimal; little-endian.
3.
Number of remaining cache: indicates the quantity of GPRS data stored in the
cache, including the quantity of data sent now; contains 4 bytes; hexadecimal;
little-endian.
4.
Quantity of deleted data: decimal; big-endian. After receiving CCC compressed
packets from the tracker, the platform will send a command to confirm. Then
these compressed packets stored in the tracker will be automatically deleted. For
example, command
CCC,6
. It means that the platform has receiving 6 pieces of
compressed GPRS data and the data in the tracker will be automatically deleted.
5.
AAA longitude and latitude packet: little-endian. Longitude and latitude packet size
varies according to tracker models. For details about the compression format, see
section 1.2 "Tracker Command Format."
6.
N: contains 1024 bytes; indicates the quantity of compressed GPRS data; depends
on tracker's compression ability.
7.
How to transmit CCC data: When the tracker is online, the platform sends
CCC
. It
means that the tracker needs to send cache data in CCC format. If no cache data is
stored in the tracker, set the quantiy of cache data to
0
and then upload data in
the following CCC format:
$$A794,011691002310418,CCC,<
Compression protocol
version
><
AAA longitude and latitude packet length
><0>*D5
. If there are multiple
pieces of cache data, data will be uploaded in CCC compression format. After
receiving data from the tracker, data will be decompressed and the data identifier
will be stored. If
N
(data identifier) pieces of data is compressed successfully, the
platform will send
CCC,
N
to confirm data receiving. Then the tracker will confirm