Post by Todd H.Post by Barnabas CollinsBut the ones they use in pets are not RFID. RRIDs put out a signal
which pet chips don't. You need a scanner for the pet chips.
Two completely different technologies.
You are very wrong.
Post by Barnabas CollinsPet chips don't use radio waves where RFID does.
How the heck do you think the info is tranmitted across the skin if
not RF? Telekenesis? Think about it.
Scanners for RFID's emit RF to energize the chips (chips include a
rectifier to convert the RF energy to power up the chip) and a
transmitter on the chip is activated to transmit a modulated digital
bitstream to a radio receiver in the scanner.
Since someone just asked me how he could obtain an RFID reader
for the several RFID implanted devices he has (none including
pets or maybe he didn't mention that) and I've spent a few days
reading this stuff maybe I can confuse things even more here.
As one trade magazine put it, there is so much flexibility in
RFID implementation that there is almost no standardization and
no economy from having everyone use the same thing.
RFID can, depending on what they design into it, have a range
from a few centimeters to miles. The companies are hoping this
is going to be the barcode of the new millenium and be put into
everything from shoes to pill bottles to cars to pets to ups
packages to credit cards to railroad cars.
RFID can use any one of 4-6 different frequency ranges. And it
can use any number of different chip company's incompatible
protocols, even if using the same frequency.
This was what caused an outcry when one company had been in the
pet RFID business for a while, a second company wanted some of
the business, introduced incompatible RFID devices and they
couldn't be read by the previous reader. That meant forcing
vets to buy another reader or having a pet not come up with a
code if you checked with the "wrong" reader.
And then there are even battery powered RFID and non-battery
powered (passive) RFID devices. I'm thinking the battery
powered ones are used for much longer range applications.
Finally there are read-only devices or there are read-write
devices. For read-only the code is in them, you can read it
out, that is it. For the are read-write ones they have memory
inside that can be updated, sometimes tens of thousands or even
millions of bits and growing. I think this is where the
"smart card" people want you to end up going.
However, for pets I believe these are no battery read only
devices and the only variation are the two companies that
are in the business with the incompatible RFID chips/readers,
unless there was enough backlash that they were finally
forced to make compatible parts and/or readers. But I
believe both of these required a radio signal sent to the
part that then provided the stimulus to get the code back
from inside the part. I haven't tracked down whether the
two companies were using different frequencies or just
incompatible chips/readers.