BOX tracker
Communication Protocol v1.5
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2
Communication Methods
Commands can be sent to and from BOX-tracker via several methods depending on setup:
Remote connection over GPRS (TCP)
Local RS232 connection
Local USB connection
Remote connection over GSM (CSD)
To configure via its serial port requires a VT100 terminal emulation program such as HyperTerminal,
configured to 115200 baud, 8 data bits, no parity, 1 Stop bit, no flow control.
Commands sent by SMS text message to the tracker must take the following format:
>
password
,command1,value;command2,value;command3,value……..
Where
password
is the password of the tracker – see password command.
2.1
GPRS (TCP) Connection
TCP over GPRS is the main communication method and all connections are initiated by BOX-tracker
connecting to the server using a TCP socket. Connections initiated from the server to BOX-tracker are
not supported. If required an SMS command can be sent to BOX-tracker to request it to initiate a
connection with the server otherwise it will connect based on configurable settings.
Once a TCP connection has been made BOX-tracker will pass all logged information without the server
having to make a request. In this situation the communication between BOX-tracker and the server can
be minimal making it easy and quick to develop a communication interface. During a connection the
server may also send commands to BOX-tracker thus providing two way communications. If a
connection is interrupted BOX-tracker will initiate a new connection and resume communication
without loss of data as long as these protocols are followed.
When a connection is first opened a header command is sent to the server. This command identifies the
tracker and provides the server the ability to verify if the connection is valid for security reasons. The
header does not need any response from the server and can be ignored if preferred.
Following the header the tracker will send log commands containing the data logged since the last
connection and which have not been sent to the server successfully.
After sending the logged commands BOX-tracker will send an END (
E
) command to notify the server all
data has been passed. The server should respond with an ACK (
A
) command so the tracker knows the
data has been received, thus preventing it from being sent again.
BOX-tracker will process any command the server has sent prior to the above ACK command. If no
commands have been sent or once they have been processed the tracker will drop the connection,
unless configured to keep it open. If the connection is configured to remain open then logged data will
be sent in real-time at intervals based on configurable settings.
