Seite 44 von 72
User Manual
Petwalk Solutions GmbH
6.3 DETECTION RANGE OF RFID-COLLAR TAGS AND RFID-CHIPS
RFID is a near field communication technology and works initially over a distance of a few centimetres. The
reading range of
RFID collar tag SMALL
is approx. 0 – 15 cm (0 - 6 in), for the
RFID-collar tag
LARGE
it is
approx. 0 – 20 cm (0 - 8 in). The typical reading distance of a well placed
implanted RFID-chip
(given it is
recognised at all) is around 0 - 5 cm (0 - 2 in). In learning mode, the chips are recognised at roughly half of the
normal reading distance.
The
actual achievable range
is dependent on many factors. The biggest challenges are the
power supply of
the transponders
, the transmission frequency and the position of the transponders in relation to the antenna.
• Regarding the power supply, there are legal regulations such as how much energy an antenna can emit
without disturbing other electronic devices in its proximity (EMC standard). Depending on the quality of
the RFID chip in or on your pet, it might need more or less energy to activate itself. This means it can
be less or further away from the antenna.
• The principle is called proximity transmission or inductive coupling. The distance between the two
coils represents the wireless transmission link and should be as small as possible. When the distance
between the two coils is larger, the flux leakage increases, the inductive coupling sinks and efficiency
decreases. Typical distances that can be bridged by this method are roughly the coil diameter and up
to double the coil diameter. The coil diameter of the transponder in your pet is just a few millimetres.
Therefore, the theoretically achievable distance is limited to a few centimetres / inches. As the collar
tag is much larger, it works better.
• The second challenge is the correct transmission frequency. This is set by default and the petWALK pet
door abides by it (it is calibrated daily). However, the
implanted RFID chips in particular, often have
considerable deviations.
This means that they don‘t transmit at the stipulated frequency. A simple
comparison would be listening to a radio program on a radio where the frequency has been adjusted.
One can hardly understand anything due to the interference. The data can only be recognised once the
signal is much stronger - in our case, once the animal has approached the antenna.
• The third factor is the position of the transponders in the electromagnetic field. This refers to how the
RFID chip, that looks like a grain of rice, is aligned to the antenna in the door leaf. It works best when
situated normally in front of the door leaf and badly when situated parallel to the door leaf. This has
physical reasons (the coil‘s magnetic field) as a result of the construction of the implanted transponder.
This has a dramatic effect on the reading range from functioning well to not at all.
In order to maximise the distance, petWALK doesn‘t read the numerical value of the chip like vets‘ devices.
Instead, petWALK analyses the RFID chip‘s frequency spectrum using complex mathematical methods and
compares it with the patterns saved previously.
The range of the RFID chip can not be adjusted on the
petWALK pet door.
The following picture illustrates the signal strength of the RFID antenna and the ideal reception quality:
As the RFID antenna is foam-sealed into the middle of the door leaf, the reception
quality is at its best in the middle. The reception quality decreases towards the
edge of the door leaf.
Therefore, whilst installing the petWALK pet door, it is essential to make sure that
the door is installed at the correct height in order to ensure that your pet‘s RFID
chip is at an optimal height for the RFID antenna. It is particularly important that
the door not be installed too high.
Please not the maximum reading range of chips which is approx. 0 – 15 cm (0
- 6 in) for the
RFID collar tag SMALL
, approx. 0 – 20 cm (0 - 8 in) for the
RFID-
collar tag
LARGE
and around 0 - 5 cm (0 - 2 in) for an
implanted RFID-chip
(given it is recognised at all) is.Your pets will need some time to get used to how
to best approach the petWALK door for it to open with activated RFID control.
Summary of Contents for petWALK
Page 1: ...User Manual VERSION 4 1...
