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Animal tag and RFID reader/writer module
with external antenna.


low cost animal tag reader with rs232
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Technical Data
   Datasheet RFID Reader Module data

low cost animal tag reader with usb
Technical Data
   Datasheet RFID Reader Module data

Download USB driver
The RFIDRW-E series are RFID reader writer modules with an externally connected
antenna coil for allowing greater application flexibility. As well as the popular
EM4100, T5557/67, EM4205 / EM4305, and TIRIS transponders this unit
can also read animal identification tags using the FDX-B and HDX protocols
as described by ISO11784/11785.

This unit comes supplied with our standard rfidcoil-49a antenna coil which
needs to be connected for the unit to operate. Alternatively users can attach
their own antenna and tune the unit by means of attaching a suitable tuning
capacitor as described in the data sheet and further below.
These units are available with either RS232 or USB interface.

Its features are: 
  • Read/Write FDX-B, and HDX animal identification protocol as described
    in ISO11784/11785, such as the Texas Instruments RI-TRP-RE2B,
    TROVAN ID162 FDX-B,  and similar transponders.
    Read EM4100 compatible transponders. (64bit Manchester Encoding).
    Read and Write T5557/67 transponders (32cyc/bit  Manchester Encoding).
    Reads and Writes EM4205 / EM4305 transponders (32cyc/bit Biphase
    Texas Instruments TIRIS 64 bit and Multi-page transponders:
        RI-TRP-R… 64 bit Read Only
        RI-TRP-W… 80 bit Read/Write
        RI-TRP-D… 1360 bit Multi-page 17 pages Read/Write
  • Read Distance: >5cm (2)
  • Comes supplied with 1 x RFIDCOIL-49A antenna.
  • Small unit size:  66x37mm (232), and 53x36mm (USB)
  • Output control for a duel color LED for Pass indication
  • Buzzer Output Control for Pass indication.
  • Free RFID application programs available for download.

(*1) For animal identification transponders that follow FDXB and HDX specifications according to ISO11784.
Trovan FDX-A transponder technologies are not supported.
(*2) Reading range indicated is based on connection of our RFIDCOIL-49A antenna. Reading range may increase
or decrease depending on the specifications of the antenna attached, transponder type,and power supply conditions.

About FDX-B and HDX animal identification.

The RFIDRW-E is able to read animal identification tags that are encoded using the standard FDX-B and HDX protocol as described in the ISO 11784 & 11785 standards. When animal tag reading is selected the
RFIDRW-E will first scan for FDX-B transponders and then HDX transponders in alternate fashion. For a more detailed description of  FDX-B and HDX animal identification transponders see
FDX-B Animal Identification Protocol description.  and  HDX Animal  Identification Protocol description.

RFID antenna basics.

In a RFID reader the antenna is a simple inductor, typically in the form of a coil. When an inductor is
coupled to a capacitor and driven by an alternating signal the amplitude of the voltage across the inductor
varies depending on the values of the drive frequency, the inductor, and the capacitor. This tuned circuit is
illustrated in Figure 1. When the frequency reaches a critical value the voltage across the inductor reaches a
maximum value which can be many times the amplitude of the driving voltage. This is known as the
resonant frequency. RFID readers typically operate at this resonant frequency to maximize the power
transferred to the antenna.

basic rfid antenna design
Where LR = Inductance of the antenna.
          CR = Tuning capacitor added.
          Rs = Series resistance of the antenna and circuit.

    Figure 1. Basic tuned circuit.

The resonant frequency of a tuned circuit can be found using the following formula.

tuning frequency of a resonant circuitWhere fo = the operating frequency
LR = is the antenna inductance.
CR = value of the tuning capacitor

    Equation 1. Calculating the resonant frequency

Connecting the RFID antenna.

The antenna drive on the RFIDRW-E uses a self adaptive carrier frequency circuit to locate the antenna
resonant frequency. This means that the antenna drive circuit will automatically tune the operating
frequency to the antenna and tuning capacitor being used. This maximizes the power transferred to the
antenna and increases read range. The drive circuit can operate anywhere in the range from 100 to 150 kHz
depending on the values of LR and CR.

The RFIDRW-E has a series of terminal pads for antenna connection and configuration. These connection
pads are designated A+, AR, A-, CT, VC, and VR. There is also a connection pad TP which allows the
current operating frequency to be measured by a frequency counter. Figure 2 illustrates the antenna drive
circuit with a typical antenna connection.
rfid antenna drive circuit


                                            Figure 2. Antenna Drive Interface

This unit is designed to be connected to our standard RFIDCOIL-49A antenna but can easily be used with other
coil antennas. Internal tuning capacitors Cri and Series Resistor Ri preset the unit to operate at 134Khz when
used in conjunction with the RFIDCOIL-49A to minimize external components. When used with any other
antenna coil a tuning capacitor is required to set the units operating frequency which is typically 125kHz, or
134kHz depending on the transponder type. Examples of connecting various antennas are shown below.

rfid coil connection for 134khz
134kHz reader with RFIDCOIL-49A  

                            125khz coil example                           
1254kHz reader with RFIDCOIL-49A 

connecting a rfid antenna to the rfdreadrw-e

Connecting a generic rfid antenna
with sample calculations.

rfid antenna calculations


                    We also design, manufacture and sell:

RFID Products:

RFID Reader Modules
RFID coils
RFID cards and keytags
RFID reader IC's     

Proximity keypads
TTL to RS232/485/USB converters

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