Subflow to send and receive SMS via Serialport & SIM800 Modul.
Input from Serial Modul
msg.input
= SERIAL_INPUT
msg.payload
= payload from Serial Modul
Start Connection to GSM Modul
msg.input
= START
Stop Connection
msg.input
= STOP
Reset SIM800
msg.input
= RESET
Send Message SMS
msg.input
= SEND_SMS
msg.payload
= {"number":"01741234567","message":"Nodered Test SMS"}