GPRS Communication Protocol

Between GPS Tracker and Server

 

 

I Command Format

 

Command format of GPRS packet is as follows: From server to tracking unit:

@@<L><ID (7 bytes)><command (2 bytes)><data><checksum (2 bytes)>\r\n

From tracking unit to server:

$$<L><ID (7 bytes)><command (2 bytes)><data><checksum (2 bytes)>\r\n

 

 

Note:

Do not input ‘<’ and ‘>’ when writing a command.

All multi-byte data complies with the following sequence: High byte prior to low byte

 

 

Item	Specification
@@	2 bytes. It means the header of packet from server to tracking unit. It is in ASCII   code (Hex code: 0x40)
$$	2 bytes. It is the header of packet from tracking unit to server, It is in ASCII code   (Hex code: 0x24)
L	2 bytes. It means the length of the whole packet including the header and ending character and it is in hex code
ID	7 bytes, the unused byte will be stuffed by ‘f’ or ‘0xff’. It is in the format of hex code. For example, if ID is 13612345678, then it will be shown as follows: 0x13, 0x61, 0x23, 0x45, 0x67, 0x8f, 0xff.
Command	2 bytes. The command code is in hex code. Please refer to the command list below.
Data	Min 0 byte, max 100 bytes.
Checksum	2 bytes. It indicates CRC-CCITT(default is 0xffff) checksum of all data (not   including CRC itself and the ending character). It is in hex code. For example: 24 24 00 11 13 61 23 45 67 8f ff 50 00 05 d8 0d 0a   0x05d8 = CRC-CCITT (24 24 00 11 13 61 23 45 67 8f ff 50 00)
\r\n	2 bytes. It is the ending character and in hex code (0x0d,0x0a in hex code)

 

_{II Command List}

 

Command	Definition
0x0001	Heart Beat
0x0002	Get IP and port
0x4101	Request one single location report
0x4102	Set time interval for continuous tracking
0x4103	Set authorized phone number
0x4130	Set telephone number for wiretapping
0x9003	Read authorized phone number
0x9955	Single location report
0x9956	Black box report
0x9957	Send SMS
0x9958	Get plain address

 

III Command Details

 

 

1.    Heart Beat

Command code: 0x0001

Command from tracking unit to server:

$$<L><ID><0x0001><checksum>\r\n

 

 

Message from server to tracking unit:

@@<L><ID><0x0001 ><Flag><checksum> \r\n

 

 

 

If Flag

=0x00, it means operation failed;

=0x01, it means operation succeeded.

 

 

2.    Get IP and port

Command code: 0x0002

Command from tracking unit to server:

$$<L><ID><0x0002><checksum>\r\n

 

 

Message from server to tracking unit:

@@<L><ID><0x0002 ><IP:port><checksum> \r\n

 

 

IP: The IP address of server

Port: The port of server

For example:

@@<L><ID><0x0002 ><118.128.198.38: 8090><checksum> \r\n

 

3.    Request One Single Location Report   

Command code: 0x4101

Command from server to tracking unit:

@@<L><ID><0x4101><checksum>\r\n

 

Upon receipt of the above command, the tracking unit will send the following message with its current

location to the server:

$$<L><ID><0x9955><data><checksum>\r\n

 

 

 

Please refer to annex 1 for detailed description of ‘data’.

 

 

4.    Set TIME Interval for Continuous Tracking       

Command code: 0x4102

Command from server to tracking unit:

@@<L><ID><0x4102><timer interval in hex code (2 bytes)><checksum>\r\n

 

 

 

Note:

2 bytes of timer interval is in format of 1 seconds and if

=0, it means stop tracking

Max time interval = 65535*10 seconds

 

Message from tracking unit to server:

$$<L><ID><0x5100><Flag (1byte)> <timer interval (2 bytes)><checksum>\r\n

Note: If Flag

=0, it means setting failed,

_{=1, it means setting succeeded}

When time interval is set successfully, the tracking unit will send the following message with its current

location to the server at the interval specified:

$$<L><ID><0x9955><data><checksum>\r\n

 

 

 

Please refer to annex 1 for detailed description of ‘data’.

5.    Set Authorized Phone Number      

Command code: 0x4103

Command from server to tracking unit:

@@<L><ID><0x4103><button number><authorized phone number for receiving

SMS><authorized phone number for receiving call><checksum>\r\n

 

 

 

Remarks:

Button number – 1 byte and in hex code. It can support up to 4 buttons. Currently only have three speed dial buttons (SOS, button 1, button2 and button3). Therefore for these trackers, if button number,

= 0x01, to set authorized phone number for SOS button;

= 0x02, to set authorized phone number for button 1;

= 0x03, to set authorized phone number for button 2.

= 0x04, to set authorized phone number for button 3.

 

 

Authorized phone number – 16 bytes in ASCII. If the phone number is less than 16 bytes, the blank byte(s) should read as ‘0x00’. For example:

If the authorized number is 8613612345678, then is should be written as follows:

0x38 0x36 0x31 0x33 0x36 0x31 0x32 0x33 0x34 0x35 0x36 0x37 0x38 0x00 0x00 0x00

If all 16 bytes data are 0x00, it means the authorized number is invalid.

 

 

After the above command is received, the tracking unit will send the following message back to the server:

$$<L><ID><0x4103><Flag><checksum>\r\n

If Flag (1byte)

=0x00, it means setting failed;

=0x01, it means setting succeeded.

 

6.   Set Telephone Number for Wiretapping (Listen Only)     

_{Command code: 0x4130}

 

9

Command from server to tracking unit:

@@<L><ID><0x4130><data><checksum>\r\n

 

 

 

Data is the telephone number for wiretapping and it should be numbers or ‘+’ and numbers. Max

16 digits. In

ASCII code.

 

 

Message from tracking unit to server:

$$<L><ID><0x4130><Flag><checksum> \r\n

 

 

 

If Flag

=0x00, it means operation failed;

=0x01, it means operation succeeded.

 

 

 

7.   Read Authorized Phone Number  

Command code: 0x9003

Command from server to tracking unit:

@@<L><ID><0x9003><button number><checksum>\r\n

 

 

 

Button number: 1 byte and in hex code, it should be in the range form 1 to 4. When button name is

0xff, it is

to read all authorized numbers.

 

 

Message from tracking unit to server:

$$<L><ID><0x9003><authorized phone number for receiving SMS><authorized phone number for receiving call><checksum>\r\n

 

 

 

Authorized phone number: 16 bytes in ASCII. If the phone number is less than 16 bytes, the blank byte(s)

read as ‘0x00’.

 

 

 

8.  Report Black Box Location

Command code: 0x9956

Command from tracking unit to server:

$$<L><ID><0x9956><data;data;data;data;data;data;data;…data;data;data;><checksum>\r\n

 

 

Remarks:

The max number of data is 40.

 

 

Please refer to annex 1 for detailed description of ‘data’.

 

 

 

Message from server to tracking unit:

@@<L><ID><0x9956 ><Flag><checksum> \r\n

 

 

 

If Flag

=0x00, it means operation failed;

_{=0x01, it means operation succeeded.}

9.  Send SMS

Command code: 0x9957

Command from server to tracking unit:

@@<L><ID><0x9957><phone number><SMS data><checksum>\r\n

 

 

Remarks:

phone number-16 bytes in ASCII. If the phone number is less than 16 bytes, the blank byte(s)

should read as ‘0x00’. For example:

If the authorized number is 8613612345678, then is should be written as follows:

0x38 0x36 0x31 0x33 0x36 0x31 0x32 0x33 0x34 0x35 0x36 0x37 0x38 0x00 0x00 0x00

If all 16 bytes data are 0x00, it means the authorized number is invalid.

 

 

SMS data-Max 70*4 bytes in Unicode. For example:

_{If the SMS data is “深圳市南山区”, then is should be written as follows:}

0xF1 0x6D 0x33 0x57 0x02 0x5E 0x57 0x53 0x71 0x5C 0x3A 0x53 0x00 0x00

This field must use 0x00 0x00 for end.

 

 

After the above command is received, the tracking unit will send the following message back to the server:

$$<L><ID><0x9957><Flag><checksum>\r\n

If Flag (1byte)

=0x00, it means setting failed;

=0x01, it means setting succeeded.

 

 

 

10.  Get plain address

Command code: 0x9958

Command from tracking unit to server:

$$<L><ID><0x9958><phone number><GPS/Cell data><checksum>\r\n

 

 

Remarks:

phone number-16 bytes in ASCII. If the phone number is less than 16 bytes, the blank byte(s)

should read as ‘0x00’. For example:

If the authorized number is 8613612345678, then is should be written as follows:

0x38 0x36 0x31 0x33 0x36 0x31 0x32 0x33 0x34 0x35 0x36 0x37 0x38 0x00 0x00 0x00

If all 16 bytes data are 0x00, it means the authorized number is invalid. Please refer to annex 2 for detailed description of ‘GPS/Cell data’.

Message from server to tracking unit:

_{@@<L><ID><0x9958><phone number><SMS data><checksum>\r\n}

 

12

 

SMS data-Max 70*4 bytes in Unicode. For example:

_{If the SMS data is “深圳市南山区”, then is should be written as follows:}

0xF1 0x6D 0x33 0x57 0x02 0x5E 0x57 0x53 0x71 0x5C 0x3A 0x53 0x00 0x00

This field must use 0x00 0x00 for end.

Annex 1: Description of data

 

 

1, Data

Data consists of: GPRMC | HDOP | Altitude | Cell | State | Alarm | Battery | Signal

 

 

For example:

100008.000,A,2232.4679,N,11356.7805,E,0.204,89.22,210911,,|7.49|152.6|3571,9763,00,460|0000|00|100|100

 

 

(9)  GPRMC includes: hhmmss.dd,S,xxmm.dddd,<N|S>,yyymm.dddd,<E|W>,s.s,h.h,ddmmyy For example:

134829.486,A,1126.6639,S,11133.3299,W,58.31,309.62,110200

_Details:

 

 

Parameter	Description	Example
hhmmss.dd	UTC time hh = hours; mm = minutes; ss = seconds;   dd = decimal part of seconds	13:48:29.486
S	Status indicator, A = valid, V = invalid	A=Valid
xxmm.dddd	Latitude   xx = degrees;   mm = minutes; dddd = decimal part of minutes	11 deg. 26.6639 min
<N|S>	Either character N or character S N = North, S = South	S = South
yyymm.dddd	Longitude   yyy = degrees;   mm = minutes; dddd = decimal part of minutes	111 deg. 33.3299 min
<E|W>	Either character E or character W E = East, W = West	W=West
s.s	Speed, knots	58.31 Knots
h.h	Heading	309.62 deg
ddmmyy	Date   dd = date;   mm = month’ yy = year	11th, Aug. 2000

 

 

(2) | is list separator in ASCII (=0x7c)

 

 

_{(3) HDOP, in ASCII code, 0.5-99.9. HDOP is blank when the tracking unit has no GPS fix.}

 

17

_{CITYEASY GPRS Communication Protocol}

 

 

 

 

(4) Altitude, in algorism.

 

 

(5) Cell, includes: cid,lac,mnc,mcc For example:

4272,10147,00,460

_Details:

 

Parameter	Description	Example
cid	Cell ID	4272
lac	LAC	10147
mnc	MNC	00
mcc	MCC	460

 

 

(6) State: Status of input and output

Bit0~Bit7: Reserved and default as ‘0’

 

 

Bit8: Status of Input1

 

If Bit8=0: Input1 is inactive; Bit8=1: Input1 is active (SOS button is pressed)

 

 

Bit9: Status of Input2

 

If Bit9=0: Input2 is inactive; Bit9=1: Input2 is active (Button 1 is pressed)

 

 

Bit10: Status of Input3

 

If Bit10=0: Input3 is inactive; Bit10=1: Input3 is active (Button 2 is pressed)

 

 

Bit11: Status of Input4

 

If Bit11=0: Input4 is inactive; Bit11=1: Input4 is active (Button 3 is pressed)

 

 

Bit12: Status of Input5

 

If Bit12=0: Input5 is inactive; Bit12=1: Input5 is active (Answer button is pressed)

 

 

Bit13: Status of Input6

 

If Bit13=0: Input6 is inactive; Bit13=1: Input6 is active (“Hang up/Power key” button is pressed)

 

 

_{(7) Alarm: Alarm command}

 

Alarm code	Definition
=0x01	SOS button is pressed
=0x02	2nd button is pressed
=0x03	3rd button is pressed
=0x04	First button is pressed
=0x05	Reserved
=0x10	Low battery alarm
=0x11	Over speed alarm

 

18

_{CITYEASY GPRS Communication Protocol}

 

 

=0x12	Movement alarm
=0x13	Reserved
=0x14	Alarm of tracking unit being turned on
=0x15	Alarm of tracking unit entering blind area
=0x16	Alarm of tracking unit leaving blind area
=0x31	SOS button is released
=0x32	2nd button is released
=0x33	3rd button is released
=0x34	First button is released
=0x35	Reserved
=0x40	Vibrate alarm

 

 

(8) Battery: Percentage of the battery voltage

 

 

_{(9) Signal: Percentage of the signal strength}