Tunnel – Example of meter reading via IP connection for real-time readings and for Energy operator. Preference for Energy operator’s IP connection

Scenario details:

• We need to read an energy meter, periodically, every 10 minutes through a 3G-RS232 gateway. We will call it “Real-Time” connection
• In parallel, an energy operator (like Endesa, Iberdrola, …) once a day will establish a IP connection (i.e., a 3G-RS232 gateway AS WELL, NOT A GSM CALL) to carry out the daily meter reading
• Operator’s IP connection should be of TOP PRIORITY. That is to say, when receiving a IP connection from the energy operator, the modem should “freeze” the ‘Real Time” connection to give way to operator’s readings. “Real Time” communication should be re-etablished after the operator’s IP connection is ended

Config.txt configuration file:

Configuration	Observations
COMM_baudrate: 9600 COMM_bitsperchar: 8 COMM_autorts: off COMM_autocts: off COMM_stopbits: 1 COMM_parity: none GPRS_apn: internetestatico.movistar.es GPRS_login: MOVISTAR GPRS_password: MOVISTAR GPRS_timeout: 0 MTX_mode: server MTX_model: 199801422 MTX_ping: 35 MTX_pingIP: 8.8.8.8 MTX_port: 20010 MTX_portb: 20011 Firewall_enabled: off	Serial port baud rate Number of bits No flow control No flow control 1 stop bit No parity GPRS APN GPRS Login GPRS Password Modem is always GPRS connected MTX server mode MTX terminal model Ping every 35 minutes without comms IP address to ping TCP port for real time reading ETCP port for Energy Operator Accept incoming connections from any IP

Details:

• RS232 port of MTX-Java-T modem is used to establish a 3G-RS232 transparent gateway
• 2 simultaneous 3G-RS232 gateways are created. 1 in TCP20010 port, other in TCP 20011 port
• Both gateways can’t run simultaneously. When the operator establishes connects with 20011, communications with 20010 are suspended. Then, only the operator has access to the meter
• When the operator connection ends in 20011, communications with 20010 are resumed