I have a Venus GX device and want to set an alarm if 'someone' moves it. I know I can connect a GPS to the GSM GX cellular modem but can I set an alarm without using a GPS device (perhaps using Lat / Long or Speed alarm rules?). If so how will the unit 'know' it has moved - does it 'know' its location if I have set it manually on the VRM portal or is that simply a 'point' that I have designated it to be on a map and it does not really know its own location.