SMS commands: 

1normal, 1stop, 2normal, 2stop - relay control. 

numbers - list of phone numbers. 

status - relay status. 

signal - network quality.  

REPx:+123456789012 - Replace phone number with new one. 

resetall - remotely format. 

help - help. 

Serial commands: 

op - Print cellular operator name. 

reg - Is registered to network, bool. 

list - Print SMS indexes. 

del - Delete all SMSes. 

format - Same as 'resetall' SMS. 

signal - Print signal quality. 

help - Some help.