Hello,
The format for SMS commands is: "<login><space><password><space>command"
If you have not set login and password, the format will look like this: "<space><space>command"
The commands are:
setparam 240 your_sim1_apn_name
setparam 243 your_sim2_apn_name
setparam x240 <Enable>,<IP>,<port>,<protocol>,<Server Response Tmo>
<Enable> - GPRS context activation (0 - disable, 1 - enable)
<protocol> - 0 - TCP, 1 UDP
<Server Response Tmo> - time in seconds for waiting server response.
For more information please check this link:
https://wiki.teltonika-gps.com/view/FMB630_Device_Family_Parameter_list#GPRS_data_sending_settings
Best regards.
