Tunnel – Timing alarm activation of GPRS-RS232 tunnel using MTX-ULP modem

Scenario details:

• We need to collect daily data of meteorological logger equipment with an RS232 port using GPRS. We need to use a low power consumption modem as the main battery cannot be changed
• The GPRS modem has to be in low power mode (2 μA) for 24 hours
• Then, after 24 hours, the modem has to wake up and connect to the GPRS. The first task is sending their IP address to the server. The server stores this IP address in a database. Another software task in the server detects the new IP address and connects to it. The GPRS-RS232 tunnel is created and meteorological data can be obtained daily
• When the process has finished, the modem goes back into ultra low power for another 24 hours and the entire process is repeated

Solution: MTX-Tunnel firmware + MTX-Java-IoT

Config.txt configuration file:

Details:

• The remote modem sends their IP address to the server using this text string format:
  #IMEI#DNS_password#IPPublica#
  IMEI is the modem’s IMEI identifier. DNS_password is a user configurable parameter. IPPublica is the public IP address the modem gets
  The “DNS_extended: on” parameter can be also used for an extended text string format:
  #IMEI#DNS_password#IPPublica#gpio1#gpio2# … #gpio10#adc1#adc2#
• Functioning is:
  1. Modem awakes
  2. Modem sends its IP to DNS_server:DNS_port
  3. When the server receives the IP, the server detects the modem is awake
  4. The server opens a socket towards the modem IP and TCP_port
  5. The server uses IP-RS232 gateway to read the weather station
  6. Once the reading is finished, we can let the modem turn off on its own, after being awake for ULP_secondsOn or, since embedded AT commands are activated, we can send the following AT command via IP-RS232 gateway so it’s executed by the modem:
  <MTXTUNNELR 1234>AT^MTXTUNNEL=SETULPSECONDS,10</MTXTUNNELR>
  This will adjust the remaining modem time to enter ULP mode (to shut down) to 10 seconds, and the shut down will be immediate.