RFID tracking device

[bertusgeert 1]

What is the range on a RFID tag?

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As jy dom is moet jy bloei!

[Kris 0]

Measured in inches, usually. Unless you just happen to have one hell of a powereful receiver.

Sky, Muff Bro, Rodriguez Bro, and
Bastion of Purity and Innocence!™

[Lostinspace 0]

http://www.ti.com/rfid/docs/customer/faq.shtml

3. What is the write range of a tag?
The write range is based upon the type and size of the transponder. It can range between 40 to 80% of the read distance.
4. How can I achieve the optimum read range?
Generally, read range increases with size of transponder, size of antenna, the power of the reader, and the absence of noise conditions in the environment. In order to reduce the impact from noise and environmental influence check the following:
))) Computer monitor interference
))) Choice of power supply with reader
))) Antenna tuning
))) Surrounding metals
))) Common Mode noise
1. What can cause a reduction in read distance?
There are a number of factors that can influence the reading range of any RFID system. They include the influences of metal, the attenuation caused by the signals passing through different materials, environmental noise and interference.
Metal
Metal close to an antenna, or a large mass of metal (relative to the antenna size) passing an antenna, can alter the matching of the antenna's characteristics to that of the reader. Re-tuning of the antenna in-situ normally reduces this problem.
Signal Attenuation
As the frequency of a tagging system rises, the ability of the radio waves to penetrate different materials decreases. At Tag-it™'s frequency (13.56 MHz) this reduction is much less than at UHF and microwave frequencies. It is not an issue at the LF (134.2 kHz) frequency.
Environmental
If there is environmental electrical noise (RFI) in the location of the Antenna system, some reduction in the read performance may result. This RFI could be caused by:
))) a. Other transmitters in the location
))) b. Inverters on drives and motors
))) c. Electrical noise generated by moving equipment such as conveyors
))) d. Noise associated with the power supply, especially Switched Mode Power Supplies.
Shielding the antenna is often an effective way to reduce or overcome such issues. This has benefits because it not only stops the RFI but it also stops any interference generated by the Reader affecting other equipment. The shield also stops transponders (XP), which are not in the read zone from being read. A shield also allows higher power levels to be used and still keep within the regulatory limits.
Antenna systems built around a conveyor belt or a tilt tray sortation system may suffer noise from the following causes:
))) a. If there are metal rollers within the antenna system then these can modulate the signal. In this case you should replace them with plastic rollers.
))) b. Ensure that the conveyor and tilt tray systems are completely grounded (earth bonded). Conveyors and tilt-tray systems are made from metal sections, which are bolted together and use linear motors to drive them. Unfortunately, at the connecting points the metal is painted which does not give a good earth bonding. So ensure that you remove the paint from the metal and earth bond the metal work which passes through the antenna system.
How can you reduce the read range? Normally everyone wants maximum read range, but the quickest way to achieve a reduced range is to turn the RF power down. Having done this, you must check that you have not created any read holes.

3. What is the maximum Read-range?
There is no single answer to this question as it depends on:
))) 1. Reader antenna size
))) 2. Tag antenna(s) size
))) 3. Reader RF power (legal limitations)
))) 4. Environmental noise
))) 5. Reading mode
With the large inlay (RI-I12-110A-00) you can achieve over 1 meter (40 inches) with opposing antennas. As a conservative rule, for a single antenna, the reading distance will be around the same as the smallest dimension, so a 400mm x 500mm antenna will be capable of reading 400mm. Readings from a single large antenna of much greater than 800mm, (all conditions optimum) should not be expected.

4. What is the minimum separation between Tags?
There is no minimum separation between tags. Using the SID (anti-collision algorithm), multiple tags close to the antenna can be readily identified but if they are at the extreme reading range, they will require some separation (5 cm) to prevent mutual de-tuning. If individual tags are passing an antenna, some separation will need to be maintained if the anti-collision algorithm is not being used. The separation is related to the size of the reading zone and should be sufficient that only one tag is in the field at one time.

7. What is the maximum antenna size?
There are 3 limiting factors to be considered:
))) Legislation
))) Matching difficulties
))) Performance degradation
Legislation
The larger the antenna, the greater the signal strength will be at a distance from the antenna. You have to keep the antenna sizes down, if you wish to operate legally without screening.
Matching
An antenna is a resonating circuit having resistance, inductance and capacitance. To make the antenna resonate is a balancing act between the inductive and capacitive reactances. As the antenna size increases, the inductance also increases and you can reach a point where matching such antennas become very difficult, as it requires very small values of capacitance to complete the balance.
Performance degradation
When antennas get too large, the RF field weakens and operations such as anti-collision reading and writing become difficult. Larger antennas also have a worse signal to noise ratio.
Once antennas exceed 900mm x 900mm, the performance may decrease.

Using inductance-measuring equipment at 13.56 MHz.
This is the most accurate but will not be an option for most people because of the cost of the equipment.
Using an LCR meter
These are relatively inexpensive but as they measure typically at a frequency of 1 kHz, are not as accurate.
Calculating the inductance
This is the least accurate. Most formulas are based around multiple winding circular antennas but TI's "ADU.exe" program is accurate enough for most rectangular designs.

(c) Texas Instruments Incorporated. All rights reserved.

[shropshire 0]

Innocent question : Why do you ask?

Only curious, cus I'm working on a RFID (Radio Barcode Team) at the moment for a retail company..

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(.)Y(.)
Chivalry is not dead; it only sleeps for want of work to do. - Jerome K Jerome

[flyingferret 0]

Yeah, exactly.....

RUN AWAY.....
I hate RFID. It just isn't there yet. To the people working on it, it is ground breaking work. To the people trying to implement it in production...HELL NO.

If you really want to know why, I can tell you. SHort story, it just is not mature enough yet to be the wonder technology it was touted as.

--
All the flaming and trolls of wreck dot with a pretty GUI.

[jraf 0]

Actually RFID is implemented in a very broad range of applications. People just don't know it. Its a cool technology and has a lot of toys involved. Neat stuff

jraf

Me Jungleman! Me have large Babalui.
Muff #3275

[peacefuljeffrey 0]

Quote

Actually RFID is implemented in a very broad range of applications. People just don't know it. Its a cool technology and has a lot of toys involved. Neat stuff

Yeah, well, watch for the day when they start expecting us to be microchipped like our animal-shelter-adoptee friends.

It will start a war. It really will.
And there are morons in government who will ignore all the recommendations against trying it because they will be so blinded by their idiotic "well-meaningness."

I'll die before I am "encoded." But more likely than just die, it'll be about fighting to the death.

-Jeffrey

-Jeffrey
"With tha thoughts of a militant mind... Hard line, hard line after hard line!"

[flyingferret 0]

It SOUNDS cool, but totally depends on the application. Trust me, I am involved with the industry. Wal Mart made some deadlines regarding vendors and product supply using RFID, I can tell you personally that even with those dealines met, their successful ID rate at a pallet level on a loading dock is dismal. And that is just tracking pallets, not even anything more detailed.

If is in its infancy, it needs more R&D and more standards. The only large proponents right now are military/gov suppliers and WalMart suppliers. Basically the vendors paid LOTS of money to meet the deadlines and are left with mediocre success at best.

That said, I am sure that somewhere out there is using them at very close range with success. But as they were hailed as an industrial end to end tracking solution, they are not working....yet.

--
All the flaming and trolls of wreck dot with a pretty GUI.

[misskriss 0]

I think jraf is VERY involved in the industry as well.. I'll leave him to comment on it if he chooses.

[flyingferret 0]

Ahh, but which industry? The one selling it as a solution or the logistics industry trying determine between multiple choices.

--
All the flaming and trolls of wreck dot with a pretty GUI.

[shropshire 0]

Quote

RUN AWAY.....

Hell no...... not yet at least. It's funding my pay cheque

It certainly has limitations () but is an emerging technology (GEN II will help - but will not solve all of the current issues.).

The bits that work .... work fine. It all depends upon the use that you put the technology to.

(1) Single tags in a field (boxes on conveyor belts) work O.K.

(2) Active Tags in vehicles at toll booths, works O.K

(3) Multiple Passive Tags attached to RF-unfriendly materiels, moving at relatively, high speed - NAK.

We keep learning stuff and will have more answers as time goes on. The people that get the techology to work as they want, will spend loads doing so but could potentially save loads in the long run (We'll see).

To the nutter shoppers who are worried about the technology invading their privacy..
We already know what you buy, if you dont use cash to buy stuff or use a Loyalty card!
.

(.)Y(.)
Chivalry is not dead; it only sleeps for want of work to do. - Jerome K Jerome

[misskriss 0]

He'll have to comment.. as much as he tries to explain it to me I'm still not quite sure what he does. I know his title and that's about it.

[flyingferret 0]

I will agree with this, and say you have a pretty objective viewpoint. My point was it is not ready for rollout yet in a LOT of scenarios. It was hailed as a wonder technology and the people with money on the line are saying a bit different things right now.

Just like Firewire, Bluetooth, etc. Any techonology has a development life cycle, and in reality most costumers do not buy until the maturity point, sometimes even on the verge of obsolesence.

--
All the flaming and trolls of wreck dot with a pretty GUI.

[shropshire 0]

Thanks - but for me, at least, at the moment, it presents loads of very interesting challenges.



We know that we're early adopters, but it's the early bird that catches the worm... (hopefully)

..

(.)Y(.)
Chivalry is not dead; it only sleeps for want of work to do. - Jerome K Jerome

[shropshire 0]

Hi Jeffrey

Do you own a Mobile phone?
If so, is it switched on all the time?
If so they know exactly where you (well your phone anyway!) are..... provided that you're in a good reception area.


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(.)Y(.)
Chivalry is not dead; it only sleeps for want of work to do. - Jerome K Jerome

[billvon 3,120]

>I hate RFID. It just isn't there yet.

We use RFID for some inventory control and badge access. It works well for us. I agree that more work is needed before it can be used for things like UPC replacement.

[flyingferret 0]

See even the genius inventor on dropzone agrees.

The markets that are being pushed most aggressively are the ones like UPS replacement.

As for earlybirds. Go ask someone who bought HDTV 2 years ago if they have gotten many worms. In fact, just ask them how much content they got before 05 or even now. Early adopters have their place, but it can be a risky proposition.

--
All the flaming and trolls of wreck dot with a pretty GUI.

[heidihagen 0]

what would it be used for? when i was brand new here(and under a diff name), i thought it would be cool to implant them in gear because they're sooo tiny, light, cheap, and trackable. i think the biggest drawback is their short life span (about a month).. i really don't know enough about it, but it really depends where you want to put it to make it worth it. the range depends on the type of chip... more under this thread: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=1365451

i didn't lose my mind, i sold it on ebay. .:need a container to fit 5'4", 110 lb. cypres ready & able to fit a 170 main (or slightly smaller):.[/ce

[jraf 0]

Oy Vey children...RFID is a big topic and there are countless applications and generally if implemented properly it works very, very well.

I should know...I have seen an rfid reader

jraf

Me Jungleman! Me have large Babalui.
Muff #3275

[flyingferret 0]

Hmm...well you saw a reader, guess that proves it works.

/confused mumbling.

--
All the flaming and trolls of wreck dot with a pretty GUI.

[heidihagen 0]

yeah, it's everywhere and sometimes hard to spot. if a dropzone just put it on their student gear, alti's, and helmets would all work on the same freq, right? but if fun jumpers started adding it to their gear, would frequency interference ever be an issue? i don't know enough about the readers. i found a dog and the vet was able to find his owner that way (she had a chip in her teeth)... cool stuff!

"RFID tags come in a wide variety of shapes and sizes. Some tags are easy to spot, such as the hard plastic anti-theft tags attached to merchandise in stores. Animal tracking tags which are implanted beneath the skin of family pets or endangered species are no bigger than a small section of pencil lead. Even smaller tags have been developed to be embedded within the fibers of a national currency." - pulled from http://www.epic.org/privacy/rfid/

i didn't lose my mind, i sold it on ebay. .:need a container to fit 5'4", 110 lb. cypres ready & able to fit a 170 main (or slightly smaller):.[/ce

[jraf 0]

Though interesting in concept, RFID tagging of gear does not make sense yet.

It is possible to position an active UHF tag on a main canopy in order to locate it when cut away by menas of a hand held device. Read ranges of up to 2000 (or more depending on tag) feet can help location in a swamp.

jraf

Me Jungleman! Me have large Babalui.
Muff #3275

[heidihagen 0]

they put them in dogs and were trying to put them in kids to keep them from going missing. i doubt they would bother if the range was only 2,000 ft. handheld devices are mostly used with cargo, there's antennas all over the place monitoring things (money, drugs, some handbags have them)

anyway, i'd pay $30 for it just as added insurance. finding a cutaway fast is an added bonus. i'm sure someone will invent it.(and then everyone can blame rfid when they can't find their main! haha) if you are that unlucky, tags can be read through a variety of substances such as snow, fog, ice, etc.
http://www.snagg.com/ < somewhat related.

i didn't lose my mind, i sold it on ebay. .:need a container to fit 5'4", 110 lb. cypres ready & able to fit a 170 main (or slightly smaller):.[/ce

[jraf 0]

Its OK I already invented it.

jraf

Me Jungleman! Me have large Babalui.
Muff #3275

[heidihagen 0]

Quote

I should know...I have seen an rfid reader

Quote

Its OK I already invented it.

cool! maybe you can stop looking at it and put it to use. give us the details when you're done

i didn't lose my mind, i sold it on ebay. .:need a container to fit 5'4", 110 lb. cypres ready & able to fit a 170 main (or slightly smaller):.[/ce