[RE-wrenches] Low Voltage Alarm Based on cell phone text message

[Kurt Albershardt]

--On January 31, 2009 8:09:27 AM -0800 Peter Parrish <peter.parrish at calsolareng.com> wrote:
>
> We have sold an off grid system delivering 24 volts DC. The application is “mission important”. We have built in a LVD and alarm, but the client wants an "early warning" system based on sending text message to a cell phone number. So we need to program a LCD around 20% residual capacity (easier part) and a cell phone interface. I know the PPA community has a solution: high-end comm link and big bucks. Is there something simple and cheap that we can implement?

Assuming you do not have a broadband IP connection, you want a cellular modem with SMS capabilities.  These are quite common in the industrial and process automation world.  I know Multitech sells them for US networks <http://www.multitech.com/PRODUCTS/Categories/Device_Networking/wireless_modems/>  I see ads in nearly every issue of Remote Site and Equipment <http://www.remotemagazine.com/> for these and others.  There are specialized M2M network operators who will be happy to sell you a modem 
along with their service.  <http://www.numerex.com/> and <http://www.jasperwireless.com/> come to mind, but there are others.

If you do have broadband IP and a machine that is battery protected, you can use an SMPP gateway application or simply send an email (if you trust the carrier's SMTP gateway - they are generally quite reliable now, unlike the early days.)