Here are the SMS comands used on this device :
1 - Reset to default password: “pwrst”
2 - Restore factory settings: “1122”
3 - Inquire IMEI: “imei#”
4 - Modify IMEI: “imei#+no.ofimei" ( for example: IMEI#200000000000001 )
5 - LED light on/off: “led#on/led#off”
6 - Modify upload time interval: “time#+No. ( for example: time#1, time interval 1minutes, from 1-60minutes ) "MD#+number" ( for example: MD#10 , time interval 10seconds, available set to 10-60 seconds)
7a - Modify IP: “DOMAIN#domain name or IP#Port ID#” ( will return to default 365gps server if the new server unavailable ) 7b - Modify a fixed IP: SERVER#domain name or IP#Port ID# ( never return to 365gps server )
8 - APN setting: “APN#parameter#account#password#” ( if there is no account password, don't need to fill in. ) (For example, China Mobile APN is: CMNET, text message: APN#CMNET#)
9 - Restart the device: “SYSRST#”
10 - Vibration Alarm: 6666#on# / 6666#off# ( open / close vibration alarm )
11 - Remote Pickup Call: monitor#Number# ( set the monitor number) , monitor## ( cancel monitor )
12- 999 : SMS Coordinate Positioning
SMS operations:
000 # number # number # number # (binding three phone numbers, the numbers call the device will make voice monitoring, binding only one number also available)
111 (SMS recording 10 minutes pause )
222 (voice recording 10 minutes pause, auto recording , 10minutes again if any voice, every time 10minutes, cancel send SMS 555 )
333 (voice-activated dial-back call to binding numbers )
444 (delete all contents of memory)
555 (turn off all features)
666 (vibration alarm SMS to binding numbers, cancel send SMS 555)
777 (vibration alarm call to binding numbers, cancel send SMS 555)
888 (play the memory recording --- such as the next play then pause after the broadcast --- this require a speaker )
999 ( SMS Coordinate Positioning )
123#1/0 ( Open/Close auto upload location data )
0086 Chinese language , 0044 English language
some information about topin protocol is here
https://www.traccar.org/forums/topic/topin-protocol-port-5199-question/