Ghost Tags and Dropping Out

[Jim Doolittle]

I am running HS 2.2 and CheaperRFID Plug-In 2.0.1 and am still seeing ghost tags where there are multiple tags that do not exist. Most of them have tag IDs with 2-3 characters in same position as an existing tag but one of them only has one character. Am using latest firmware.

I also set up events that trigger and produce log entries when tag devices change status. I see status flipping occasionally.

Any ideas?

[Rupp]

Jim,
Do you have the newer firmware chips on your transmitters? I was having this problem until I added the "+" antenna on my receiver and extended the antenna in my transmitters. I've not had a drop out or false device in a week. This is also using the plugin from the updater.

[Tcassio]

Are you using USB -> Rs232 adapters. I've read that these can cause incomplete or fragmented tag ID's.

[Jim Doolittle]

Maybe the problem here is my expectation. The tag in question is just barely in range so maybe it is flipping on and off because of that. If so, I will need to increase range (am not using any antennae mods yet) and then make sure that it is unlikely that tag will remain just barely in range for an extended time. Otherwise, there could be problems with automation control based upon tag status.

Rupp, I am using latest firmware as I mentioned in my first post.

[Rupp]

I missed that new firmware line. I experienced the exact same issue you are when I was using the built in receivers antenna at the extreme ranges.

[Jim Doolittle]

ok. will mod antennaes soon but was still unsure what was best for both transmitter and receivers. I currently only have 8m devices.

[piperpilot]

Jim,

You will get the most bang from modifying your receiver antenna! Couple of folks get 100ft or so from the 8m with a modified antenna.

[Jim Doolittle]

Can someone post a link to the post that described the recommended the "best" receiver antennae?

I find it funny that now that piperpilot has manged to get a dedicated forum that some people are still posting to that huge thread!

[piperpilot]

I find it funny that now that piperpilot has manged to get a dedicated forum that some people are still posting to that huge thread!

You know what...I can fix that...I'm gonna lock the Super Long threads...

PiperPilot

[Rupp]

Jim,
Here's a thread from a few below on the various antennas. In my opinion the best antennas are the "shed antenna" for the receiver and the "stub" antennas for the transmitters.
http://board.homeseer.com/showthread.php?t=119411

[Jim Doolittle]

Hmm...that is the one I started. I suppose I should pay more attention to what I am doing...or trying to do.

[Jim Doolittle]

You know what...I can fix that...I'm gonna lock the Super Long threads...

PiperPilot

good idea!

[The Gemini]

Key fob drop outs

Hello all...
I keep getting VERY random drop outs with my two key fob transmitters. I have one sitting about 5' away from the receiver, and the other about 10' away. The 40m transmitter is flawless and in my car about 25' from the receiver.
As this is happening (see attached log) I am not moving or disturbing anything. It happens at all hours of the day and night.
I do have a power supply connected to the receiver with no USB adapter.

I had planned on using these for relatively short distances and don't want to turn them into mega-distance transmitters with receiver antenna mods.

Ideas???

[anogee]

This is a problem that occurs even with the more expensive iAutomate receivers that I use. I haven't seen any solution other than adding additional receivers, and at $500 each, its not cheap. With two receivers, it happens only rarely, but still does happen once in a while. Like you, even when nothing is touched, tags come and go.

I'm not sure if CheaperRFID supports multiple receivers yet, but when it does, that should certainly help. The iAutomate plug-in allows you to trigger when a tag is missing from ALL readers, and that is what I would recommend.

[Michael McSharry]

I have found this implementation of RFID to be a proof of concept and fine for non-critical hobby applications, but not something that should be considered reliable. I put a somewhat complex adaptive signal processing algorithm in xapmcsRFID and even with that I do not get the results I had expected from the transmitter. There are periods of minutes in some cases where two receivers do not hear the stationary transmitter and then they reappear again.

There is more engineering that needs to be done to use these devices as proximity indicators as I had intended. You have a better chance at using them as presence indicators, but the filtering algorithm needs to have a very slow period to get somewhat reliable results.