RFID and ideas for Fully Automated Building

elytronic

We are working on a buiding with 3 apartments that the builder will install AMX as standard. The building has 2 entrances: the main building entrance with electric door and a driveway with a metal bar for the cars. The vision of the builder was to use RFID so that when the owners arrives with the car, the bar goes up and they enter the driveway. At the same time the lift comes down and when the owners enter the lift it automatically takes them to their floor. Then as they approach the apartment entrance the door automatically unlocks.

Ok, we have a dedicated processor handling the entrance with 3 Met-Ecom-D. If we take the scanario with the car aproaching the bar, and the reader getting a signal from the tag and opens the gate I am thinking of the following problem: What happens if the owner passes from the building (throught the road) but does not enter the buiding (driveway) and the reader sees the tag - then the gate will open with no reason. The same problems can also occur with the other doors and this would be more serious because the building main door and the apartment entrance will open and the owner will probably not notice it. Is there anyway that the reader can measure the distance between it and the tag and only react if the distance is small. AMX reccomends that RFID is not used for access control but if the reader can measure the distance from the tag and can be programmed according to distance parameters then some very neat things (like the above) can be done.

If you thing going with RFID is not a good idea in this project can you reccomend solutions that we can implement so that we get similar results as the scenario I described above?

matt95gsr

I have not personally used the RFID products yet, but I did look into them for a project a couple of months ago. As I recall, the short answer is yes, they can measure the "distance" - based on RSSI. Take a look at the Anterus reader reference at http://www.amx.com//techdocs/Anterus.OperationReferenceGuide.pdf. It seems that there are a number of parameters that can be set to monitor, including RSSI and remaining battery life on the tag.

Response: TG [T<TID> R<RSSI> P<LIFE> A<AFLG> B<FUT> ?]
Where:
? TID: The tag's unique Tag ID, an 8 character string formatted such that a
tag's type can be identified by the first character.
? RSSI: RSSI strength value of tag's transmission
(Range = 0 - 255, where 0 = no signal, and 255 = max RSSI signal possible).
? LIFE: The Percent of Battery Life left on the Tag (0 - 100%).
? AFLG: Activity Flag, a single byte denoting if the tag has just crossed the
Acquired Threshold and been acquired; just crossed the Lost Threshold and
is lost, or the change in RSSI value since the last sent Tag RSSI value is
greater than the Sensitivity range. Values are:
2 for acquired,
1 for RSSI value change,
0 for lost.

The above information, as well as some levels that come from the reader, should give you the actual RSSI as well as give you control to set the thresholds that you deem appropriate.

trav

Active Tags

Also you have about 12 secods between beacon updates from the tags to the readers, as they are an active tag. There is no way to change this without haxing with the timing circuit on the RFID Card itself.

So as far as my Ideal of being able to wader around a home, R4 in hand with RFID tag in pocket... not going to fly unless I make the card update every 2 or 3 seconds which will mean I'm replaceing the card (due to battery depletion) every 3 months or so.

As well as invalidating the warranty by modifying the card.

elytronic

Yes, I have talked to AMX and it seems their product is mostly targeted towards the commercial market for asset tracking and triggering events that you do not mind if they take a few seconds to hapen... The 12 seconds make it really unsuitable for access control.

What about any third party RFID products that can be integrated with AMX?

Also, from the experienced integrators, any ideas to achieve what my customer wants with other products or solutions?