Article

How Does Our Text Messaging Device Work?

April 9, 2014

Overview

A text messaging device allows you to receive SMS alerts to any mobile phone whenever one of the inputs is grounded momentarily. You can also switch something on by sending the device an appropriate command.

The popular model we supply connects to our base receiver has two ‘zone inputs’ so that whenever one beam-set is triggered you will receive a customised SMS message like: ‘Gate 1’ / ‘Gate 2’ or whatever you like.

The unit has a GSM ‘engine’ inside, the same as you would find inside any mobile phone, except there is no keypad, screen or microphone etc. Its sole purpose is sending pre-determined SMS messages to pre-determined recipient phone numbers whenever something triggers the alert. It may also be used for controlling something from your phone.

A pre-pay or on account SIM card is first purchased from Telstra (Australia) or Vodafone then activated and inserted into the devices SIM card holder. The unit is then programmed by serial interface with a suitable PC. We usually program the device for you and test it to your phone before it leaves our factory, however you may also configure it yourself if you feel confident to do so.

Phone numbers are easily changed, deleted or new ones added by simply sending the correct command by SMS from any phone.

Other Applications

The device doesn’t have to be part of a ® solution. It is useful for many other industrial monitoring applications – whenever you need to be immediately alerted to an even via your phone.

Also incorporated are timers that can be set up to switch something on for a certain length of time whenever one of the inputs is triggered or whenever you send a special SMS instruction to the device from your phone. There are two controllable outputs available.

The outputs are low-voltage ‘open-collector’ type so if you want to switch something that is mains-voltage rated you would need to have a qualified electrician connect a suitable relay or contactor to the device.

On Prepay

The device has a low operating cost, particularly if you have purchased one of several bulk-texting plans offered by the various service providers. For example the plan we typically set up for our customers is the TXT NZ plan through NZ Vodafone and costs $12 per month for 2500 TXTs to any NZ mobile. One thing to be careful of is to always ensure there is adequate prepay balance on the devices SIM card so that whatever TXT plan you are on automatically rolls over every month automatically.

Top-ups can be done on-line providing the SIM card has been registered, or by credit card over the phone (select the ‘top-up a different phone number’ option) or the case of Vodafone at any Westpac ATM.