"Ghost" devices

[Bastiaan]

Just a question out of interest:

When I add a device in my system, like a Visonic doorswitch, I go to the RFXCOM add device option. It finds the security device, assigns a ID and stores it in the overview. All fine.
Usually I do this untill I get the "no devices to add" message.

But when I do this a few days later I get a whole bunch of 'extra' devices. They show up, I can add them but they are never triggered.

I live in an area without any techies around so they are not from my neighbours. Where do they come from and how to distinquish between real and 'ghost' devices?

[b_weijenberg]

The normal procedure is: Click the "Clear heard" button, activate the sensor to add then Add the sensor.

All packets received of an unknown (non-configured) device are recorded as heard sensor. Some disturbed RF packets are stored as heard sensor if the packet format confirms to some criterea.