The MTX-Tunnel application with Java software uses SMS messaging to change a digital output value in MTX-65i or switch a relay in our MTX-IND terminal modem. SMS to RS232 or SMS to I2C tunneling gateway can be used to command or read data from an external device such as a display.

Relay control by SMS message and MTX-Tunnel access by Web Browser

Scenario details

• It is necessary to control four relays by SMS; for example, to enable or disable some streetlights in a remote location
• An SMS with the text ONx or OFFx (where x is 1, 2, 3 or 4) is sent so that the relays of every streetlight are either enabled or disabled. In order to do this, it is necessary to create an ALIAS text string in the modem.
• Only the 100 phone numbers allowed by the company should be able to send an SMS, starting with 6662746XX
• We want to access the relays and also activate the WEBSERVER on the MTX-Tunnel via SMS (sending SMS with an “on” string or using a missed call). WebServer is only activated for 10 minute periods, which are long enough to perform maintenance tasks such as access to relays from a PC browser or changes to any of the other MTX-Tunnel configuration settings.