OBI
D
®
i-scan
APPLICATION-NOTE
ID ISC.ANT800/600
Installation and tuning of a gate antenna
made from four base antennas.
Label reads only with parallel orientation
to the loops
final
public
2002-06-04
N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
Note
Copyright 2002 by
FEIG ELECTRONIC GmbH
Lange Strasse 4
D-35781 Weilburg-Waldhausen
Tel.: +49 6471 3109-0
http://www.feig.de
With the edition of this document, all previous editions become void. Indications made in this document may
be changed without previous notice.
Copying of this document, and giving it to others and the use or communication of the contents thereof are
forbidden without express authority. Offenders are liable to the payment of damages. All rights are reserved
in the event of the grant of a patent or the registration of a utility model or design.
Composition of the information in this document has been done to the best of our knowledge. FEIG
ELECTRONIC GmbH does not guarantee the correctness and completeness of the details given in this
document and may not be held liable for damages ensuing from incorrect or incomplete information. Since,
despite all our efforts, errors may not be completely avoided, we are always grateful for your useful tips.
The instructions given in this document are based on advantageous boundary conditions. FEIG
ELECTRONIC GmbH does not give any guarantee promise for perfect function in cross environments.
FEIG ELECTRONIC GmbH assumes no responsibility for the use of any information contained in this
document and makes no representation that they free of patent infringement. FEIG ELECTRONIC GmbH
does not convey any license under its patent rights nor the rights of others.
OBID® is registered trademark of FEIG ELECTRONIC GmbH.
General information's regarding this document
• The sign ")" indicates extensions or changes of this document compared with the former issue.
• The following figure formats are used:
0...9: for decimal figures
0x00...0xFF: for hexadecimal figures,
b0...1 for binary figures.
FEIG ELECTRONIC GmbH Page 2 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
Contents
1. Characteristics and application of the antenna gate 4
1.1. Project notes........................................................................................................................5
1.2. Required components ........................................................................................................7
1.3. Preparing the installation location / metal-free areas......................................................8
2. Installation and wiring 10
2.1. Installation instructions....................................................................................................10
2.2. Instructions for installing and routing the antenna connection cable.........................11
3. Tuning the gate 12
3.1. Preparations ......................................................................................................................12
3.2. Tuning the first base antenna ..........................................................................................14
3.2.1. Tuning the base antennas ...........................................................................................15
3.3. Tuning the second, third and fourth antenna.................................................................18
3.4. Fine tuning the two antennas on the gate side ..............................................................19
3.5. Measuring the standing wave ratio (VSWR) ...................................................................23
4. Startup and testing of the gate 24
4.1. Reading out the serial number.........................................................................................24
4.2. Checking the Noise Level.................................................................................................25
4.3. Setting the operating parameters ....................................................................................26
4.4. Testing the performance ...................................................................................................27
4.5. Switching the Reader to Buffered Read Mode ................................................................28
4.6. Regulatory agencies in EU countries and the USA .......................................................29
4.7. Shielding around the antennas........................................................................................30
5. Appendix: Helpful tools for constructing and testing the antennas 31
5.1. Recommended equipment and possible sources: ........................................................32
FEIG ELECTRONIC GmbH Page 3 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
1. Characteristics and application of the antenna gate
The antenna gate described here has been designed to read Smart Labels (transponders) on
goods carried on pallets or conveying systems. The read window with a label having a size of 46 x
75 mm (1.8 x 2.95 in). (see technical specifications in section 1.1. ) is a maximum of 1.35 m (53 in)
gate width x 1.5 m (59 in) in height.
This presumes that no large magnetic conducting materials (such as metal) are located in the vicinity of the antenna or label. The minimum separations can be found in section 1.3. .
The gate consists of four base antennas of type ID ISC.ANT800/600-A, three Power Splitters type
ID ISC.ANT.PS-A and a Reader type ID ISC.LR200-A. The Power Splitters ID ISC.ANT.PS-A are
used to connect the four antennas in correct phase and power relationships.
In order to meet the RF regulations and to enlarge the read window, two antennas per gate side
must be arranged in a special mounting configuration with proper phase and power relationship.
For detailed information on the products as well as installation notes on the individual antennas,
see the mounting instructions for ID ISC.SAT.C-A, ID ISC.ANTPS-A and ID ISC.ANT800/600. This
information may also be acquired in an antenna training course offered by FEIG ELECTRONIC
GmbH.
The mounting instructions are also contained on an
ELECTRONIC GmbH.
OBID® i-scan CD-ROM available from FEIG
FEIG ELECTRONIC GmbH Page 4 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
1.1. Project notes
The antenna configuration described here allows labels to be detected as they pass horizontally
through the gate. The label orientation must be parallel to the antennas. The labels are detected
along a horizontal line of motion in certain areas within the antennas. The precise read area depends on the distance of the label from the floor. Labels close to the floor are read by the front antennas. If the label is attached higher, it is read by the upper two antennas.
The capture area of the antennas has a size indicated in the illustration below.
Note: The overall capture area of the antenna is larger than shown in the illustration. The labels
that are oriented parallel to the antennas can also be detected at greater distances when next to or
outside the antennas.
Therefore no product having a label may be stored in the capture area near the gate antenna.
They must remain more than 0.8 m (32 inches) from the gate. Otherwise the antennas will need to
be shielded to prevent unwanted pickup of extraneous tags around the gate.
Figure 1: Capture area of the antennas
Capture area
To achieve capture of the labels that are parallel to the loop antennas within the capture area
drawn above, the following conditions must be met:
• The gate width (GD) must be less than 135 cm (53 in.).
• The distance of the lower antennas from the floor must be greater than 25 cm (10 in).
• The labels should be at least ISO card size (46 mm x 75 mm [1.8 x 2.95 in]).
• The activation field strength sensitivity of the labels should less than or equal to 85 mA/m.
FEIG ELECTRONIC GmbH Page 5 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
• The distance from label to label should be greater than 10 cm (3.9 in). .
The distance from label to label may be reduced if the gate width GD is reduced correspondingly. This applies especially to distances of less than 5 cm (1.9 in).
• No more than 16 labels at a time should be located in the capture area of the antenna. The
number of labels may be increased by correspondingly reducing the gate width GD and adjusting the maximum speed accordingly.
• The maximum speed of motion of the label should not exceed 0.5 – 1 m/s (this depends on the
number of labels, the number of data blocks, the required data protocol and the label type).
• The antenna should have a separation of greater than 50 cm (20 in) from metal parts.
• There should be no devices in the vicinity of the Reader that could cause noise interference.
The difference of the noise levels (U
max
- U
) should be less than 20 mV.
min
• The Reader ID ISC.LR200-B should be set for an RF power of 4 watts. At an RF power of
greater than 4 watts the conditions for approval according to the R&TTE directive are exceeded.
• When using ISO15963 transponders, the Readers should be adjusted as described in section:
4.6. Regulatory agencies in EU countries and the USA.
FEIG ELECTRONIC GmbH Page 6 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
1.2. Required components
The following are required to construct the gate:
• Qty. 1 ID ISC.LR200-A (Reader)
• Qty. 3 ID ISC.ANTPS-A (180-degree, two-way Power Splitter)
• Qty. 4 ID ISC.ANT800/600-A (800 x 600 mm Loop Antenna)
• Qty. 5 EMC- ferrite toroids, available from: Würth Elektronik GmbH & Co.KG, diameter da=28,
B.No.742 701 4.
The cables on the antennas ID ISC.ANT800/600 and on the Power Splitter ID ISC.ANTPS-A are
each 3.5 m (11.5 ft) long. This means the Readers should be installed near the antennas. For
longer distances between Reader and base antenna, the ID ISC.ANT.EC extender can be used to
lengthen the antenna cable to 7.20 m (23.5 ft). This will however result in a slight loss of performance.
The cable extender also requires
• 2 x ID ISC.ANT.EC
Components required for commissioning:
• Qty. 1 ID ISC.SATC-A Automatic Tuning Controller
• Service software ISCStart Version 4.00 or higher on a PC running under MS Windows. The
ISCStart software is contained on the OBID® i-scan CD-ROM available from FEIG
ELECTRONIC GmbH.
• Qty. 1 SWR Meter with SMA sockets or adapter to SMA sockets
• Qty. 1 cable RG 58 C/U approx. 20 – 25 cm long with 2 SMA plugs
• Qty. 1 amber blade screwdriver (Tuning tool for tuning capacitors)
• Qty. 1 50 Ω termination resistor with SMA male connector
For additional information on these devices, see individual instructions or section 5. !
FEIG ELECTRONIC GmbH Page 7 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
1.3. Preparing the installation location / metal-free areas
To ensure flawless operation of the gate, all larger metallic parts must be removed from the vicinity
of the antennas.
Figure 2 Metal-free zone, side view
2.50 m (8.2 ft)
50 cm (20 in)
50 cm
2.50 m (8.2 ft)
50 cm
50 cm (20 in)
If the lower antennas are installed directly over the floor, a minimum distance of 25 cm must be
maintained.
Figure 3 Metal-free zone, view from above
50 cm (20 in)
GD
50 cm50 cm
1.1 m + GD
50 cm (20 in)
FEIG ELECTRONIC GmbH Page 8 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
If metal cannot be avoided in the vicinity of the antennas, note the following:
• The minimum separation between metal and the antenna must be 10 cm (3.9 in). At 30 cm (12
in), the read distance will be significantly reduced. At more than 50 cm (20 in) there is virtually
no measurable effect.
• The effect of metal parts depends greatly on their size and shape. Thin metal rods affect the
magnetic field lines less than objects having large surface area.
• Larger metal surfaces (edge length > 50 mm) parallel to the antennas or the labels result in a
short circuit of the magnetic field lines. The result is that the label cannot be read.
• Metal parts beneath the conveyor belt change the path of the magnetic field lines. This results
in significant loss of reading range. Horizontally oriented labels cannot then be read.
• The metal parts are not permitted to form closed loops or circuits. Loops must be isolated at
some point around their perimeter to prevent formation of a closed loop.
• The metal parts in the immediate vicinity of the antenna must be grounded in star fashion using
a good High Frequency connection.
• Since the Reader is contained in a metal housing and the antennas are coupled into the cable
connected to the Reader, the Reader should be located at least 50 cm (20 in) from the antennas.
• The Reader housing should not be permitted to make any electrical connection with any metal
parts located near the antenna.
FEIG ELECTRONIC GmbH Page 9 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
2. Installation and wiring
2.1. Installation instructions
The antennas and power splitters on both sides of the gate are installed according to the diagram
below. The power splitters are connected only after calibrating the antennas. Since the Reader is
enclosed in a metal housing and the antennas couple into the Reader cables, the Reader should
be located at a distance of at least 50 cm (20 in) from the antennas. The second side mirrors side
one.
Figure 4 Installation diagram for one gate side including cabling
Two of the four base antennas are installed on one gate side, so that two base antennas always
face each other. All antennas should be installed vertically with the antenna opening/covers facing
down. The two antennas on a gate side must be oriented the same with their antenna opening/covers facing the same way. In addition the antenna openings/covers should be located either
facing out (away from the gate) or in (towards the centre of the gate).
Please note the instructions in the installation guide for the ID ISC.ANT600/800-A/B.
FEIG ELECTRONIC GmbH Page 10 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
2.2. Instructions for installing and routing the antenna connection cable
To suppress any possible noise, an EMC toroid core with dia=28 mm should be installed in the
antenna cables for the base antennas and power splitters (vendor: see appendix). Loop the coax
cable at least four times tightly through the toroid. The distance between the Reader connection
and the toroid should be less than 10 cm (3.9 in).
Figure 5: Installing the toroid on the antenna cable
The cables to the power splitters are first routed in place in the vicinity of the antenna. The power
splitter is connected only after tuning the antennas.
The antenna cable should always be routed vertically away from the loop at least 50 cm (20 in).
Also maintain a minimum distance of 50 cm (20 in) from the antennas when routing other cables.
If the antenna cable must be routed closer to the antenna, maintain a distance of at least 20 cm.
(7.8 in) otherwise you will sacrifice performance.
All antenna cables must be kept at least 30 cm (11.8 in) from parallel routed, current carrying cables.
Excess cable should be wound into a loop having a diameter of ∅ = 10 – 15 cm.
If the existing cable is not long enough, it may be extended using an ID ISC.ANT.EC extender for
an additional length of 7.20 m (23.6 ft). Slight loss of sensitivity will result.
To achieve optimum reading distances, the antenna connection cable should not be shortened or
lengthened.
Please note the instructions in the mounting instructions for the ID ISC.ANT600/800-A/B.
FEIG ELECTRONIC GmbH Page 11 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
3. Tuning the gate
Before tuning, all antennas must be installed and the cables held down near the antenna.
3.1. Preparations
Step Procedure Note
Connect the ID ISC.LR200
1
Reader to the PC through the
RS232 or RS485 port
Install the Demo Software ISC-
2
Start
Run the ISCStart program
3
Open the COM port settings
4
Check the COM port settings and
5
confirm by clicking on OK.
See Installation Manual ID ISC.LR200
Located on the OBID® i-scan CD-ROM
Now open the menu File – New -
6
Reader
Select ID ISCLR and click on OK
7
Select COM: x [Baud 38400......]
8
FEIG ELECTRONIC GmbH Page 12 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
Click on Commands
9
10
11
12
13
14
Select Baudrate Detec-
tion[0x52] command
Click on Send
The program tests all possible
baud rates. It stops as soon as
the baud rate set on the Reader
has been detected (default
38400 / 8E1) and confirms with
OK
Click on Configuration
Select ID ISCLR Configuration.
15
16
17
Select destination memory
EEPROM instead of RAM.
Click on Reset [0x83] to set the
Reader to the default configuration.
Click on Read to load the Reader
configuration into the PC and to
load the ISCStart program.
FEIG ELECTRONIC GmbH Page 13 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
3.2. Tuning the first base antenna
To tune the antenna you must first remove the cover over the antenna opening. The recommended
tightening torque of the cover screws when attaching the cover is 0.2 Nm – 0.25 Nm.
Next, connect the first base antenna directly to the Reader. Terminate the second antenna using a
50 Ω termination resistor.
Begin the tuning procedure with the first base antenna. Next tune the second base antenna. Since
the two neighboring base antennas affect each other mutually, the first base antenna must then be
retuned. The third and fourth antennas are tuned in the same sequence. Tuning begins with Antenna 3. Next Antenna 4 is tuned, and then Antenna 3 again.
Figure 6: Configuration for tuning the first base antenna
ID ISC.LR200-A
4 x ID ISC.ANT800/600-A
Antenna 2
9 cm
50 Ω termination resistor
SWR - Meter
Antenna 4
Antenna 3
20 cm
Antenna 1
25 cm
FEIG ELECTRONIC GmbH Page 14 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
A
3.2.1. Tuning the base antennas
Step Procedure
Connect the Reader to
the base antenna
through the SWR
Bridge.
See also section 3.5.
Measuring the standing
1
wave ratio (VSWR
Jumpers J1 – J4 and
J6–8 should be checked
and set as necessary.
Jumpers JP6 + JP7 are
left out
Base antenna
ID ISC
.ANT800/600-
Jumper JP3 must be in.
Note
Reader
ID ISC.LR200
SWR / Power Meter
2
Trim capacitors pair
“C2” to maximum capacitance as shown.
Set trim capacitors pair
3
C1 to mid capacitance.
JP1, JP2, JP4, JP6, JP7 and JP8 = out
2
Rges = 3 Ω
JP8
2
Ω
JP4
JP3
JP2
JP1
1
0,4
Ω
Ω
Ω
FEIG ELECTRONIC GmbH Page 15 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
Click on Commands at
4
the ISCStart Program
Window
Select the command
5
[0x6F] Base Antenna
Tunning] and click on
Send to send all the
settings.
Now connect the Static
Antenna Tuning Controller ID ISC.SAT.C-A
to the antenna tuner of
the base antenna and
press the “Start“ key on
the controller.
The tuning process
6
takes several seconds.
When completed, the
green LED will come on
for 4 seconds.
.
The controller runs then
automatically turns off
and can then be unplugged.
7
Tuning mode: Is activated by holding down the Start key
greater than two seconds (> 2 sec)
Control mode: Is activated by briefly pressing the Start key
shorter than two seconds (< 2 sec).
Important:
Do not unplug the controller until the
green LED has gone out
Now you may begin tuning the second, third and fourth antenna.
!
FEIG ELECTRONIC GmbH Page 16 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
If the tuning was not
properly concluded, this
is indicated by the red
LED.
If an error occurs at the
beginning of the tuning
procedure, the LED
flashes for 4 seconds.
If an error occurs during
or at the end of the tuning procedure, the LED
turns on solidly for 4
8
seconds.
If the battery is low, the
yellow LED turns on
for 4 seconds.
If the red LED flashes for 4 seconds, this indicates there is no
RF power at the antenna.
Possible causes:
• Reader or RF power turned off.
• Cable between Reader and antenna defective.
• The SMA connectors were not properly attached to the
Reader or antennas or are not properly seated on the SMA
sockets.
• The cable is pinched or shorted in the SMA plug.
♦ The controller was not properly plugged onto the board.
If the red LED comes on solidly for 4 seconds, the tuning was
not properly finished.
Possible causes:
• Cable between Reader and antenna is defective.
• The SMA connectors were not properly attached to the
Reader or antennas or are not properly seated on the SMA
sockets.
• The cable is pinched or shorted in the SMA plug.
♦ Modulation is turned on in the Reader.
♦ Antenna Q set too high (resistor settings).
♦ The controller was not properly plugged onto the board.
♦ Tuner board is defective.
.
FEIG ELECTRONIC GmbH Page 17 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
3.3. Tuning the second, third and fourth antenna
To tune the second antenna, connect it to the Reader through the SWR meter. Terminate the end
of the antenna cable on the first antenna with a 50 Ω resistor. Use this configuration to tune as
described in section 3.2.1. .
Since adjacent antennas will have a mutual coupling effect on each other depending on their
spacing, the first base antenna should once again be retuned.
Figure 7: Configuration for tuning the second base antenna
4 x ID ISC.ANT800/600-A
Antenna 2
9 cm
ID ISC.LR200-A
The complete procedure for Antennas 1..4 is summarized in the following:
Step Task Reader – Antenna con-
SWR - Meter
50 Ω termination resistor
nection
Antenna 4
20 cm
25 cm
Antenna 3
Antenna 1
Termination resis-
tor
1
2
3
4
5
6
FEIG ELECTRONIC GmbH Page 18 of 33 N11000-2e-ID-B.doc
Tune Antenna 1 as per section 3.2.1. Reader -> first antenna second antenna
Tune Antenna 2 as per section 3.2.1. Reader -> second antenna first antenna
Tune Antenna 1 as per section 3.2.1. Reader -> first antenna second antenna
Tune Antenna 3 as per section 3.2.1. Reader -> third antenna fourth antenna
Tune Antenna 4 as per section 3.2.1. Reader -> fourth antenna third antenna
Tune Antenna 3 as per section 3.2.1. Reader -> third antenna fourth antenna
OBID® i-scan Application-Note ID ISC.ANT800/600
g
3.4. Fine tuning the two antennas on the gate side
Fine tuning is performed individually for each gate side. For this the two antennas on one side
(Antenna 1 and 2 or 3 and 4) are connected with the Power Splitter and to the Reader through the
SWR meter.
Caution! Note the current direction in the antennas. Opposing antennas must have the same
current direction. This means Antenna 1 and 3 must be connected to terminal X1 on the Power
Splitter. Antenna 2 and 4 are connected to terminal X2 on the Power Splitter.
Figure 8: Configuration for fine tuning the first gate side
ID ISC.LR200-A
20 cm
(7.9 in)
4 x ID ISC.ANT800/600-A
SWR - Meter
Antenna 2
9 cm
Power Splitter
3,6 m
(11.8 ft)
3,6 m
(11.8 ft)
Antenna 4
20 cm
Cable len
Antenna 3
Antenna 1
25 cm
Ground
ths
Since the tuning point of the antennas will deviate somewhat from the configuration during tuning
due to the mutual interference caused by magnetic coupling, the tuning point will need to be readjusted slightly.
This can be accomplished with the help of an SWR meter and the four blue trim capacitors C1 and
C2 on the tuner boards.
FEIG ELECTRONIC GmbH Page 19 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
Step Procedure
Connect the ID ISC.LR200 Reader
1
to the first (or second) gate side.
Turn the leftmost of the two trim
2
capacitors C2 on Antenna 1 (3)
approx. ¼ - ½ turn counterclockwise.
The SWR must drop!
Always tune the SWR to the
smallest possible value.
Turn the leftmost of the two trim
3
capacitors C2 on Antenna 2 (4)
approx. ¼ turn counter-clockwise.
The SWR must drop !
Note
Figure 8:
Tune the SWR to the smallest
possible value.
Turn the leftmost trim capacitor C1
4
on antenna 1 (3) slowly counterclockwise.
The SWR must drop! Otherwise
turn the trim capacitor slowly
clockwise.
Continue tuning until the SWR
reading no longer drops.
Turn the left trim capacitor C1 on
5
antenna 2 (4) slowly counterclockwise.
The SWR must drop! Otherwise
turn the trim capacitor slowly
clockwise. Continue tuning until
the SWR reading no longer drops.
FEIG ELECTRONIC GmbH Page 20 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
6
7
8
Turn the right trim capacitor C2 on
antenna 1 (3) and Antenna 2 (4)
alternately slowly counterclockwise. The SWR must drop!
Otherwise turn the trim capacitor
slowly clockwise. Continue tuning
until the SWR reading no longer
drops.
Turn the right trim capacitor C1 on
antenna 1 (3) and Antenna 2 (4)
alternately slowly counterclockwise. The SWR must drop!
Otherwise turn the trim capacitor
slowly clockwise. Continue tuning
until the SWR reading no longer
drops.
Now the SWR reading should be
≤ 1.3:1
9
10
11
12
Repeat steps 108 for the second
gate side (Antenna 3 & 4).
Connect the two gate sides to the
Reader through the third Power
Splitter.
Repeat steps 6-7 for both gate
sides.
Now the SWR reading should be
≤ 1.3:1
See: Figure 9:
FEIG ELECTRONIC GmbH Page 21 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
Figure 9: Configuration for fine tuning the entire gate
ID ISC.LR200-A
20 cm
(7.9 in)
4 x ID ISC.ANT800/600-A
SWR - Meter
Antenna 2
3 Power Splitters
3.6 m
(11.8 ft)
3.6 m
(11.8 ft)
3.6 m
(11.8 ft)
Antenna 4
Antenna 3
Antenna 1
25 cm (10 in)
Floor
Cable lengths
FEIG ELECTRONIC GmbH Page 22 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
r
3.5. Measuring the standing wave ratio (VSWR)
Once an antenna has been calibrated or the local conditions have changed, the question arises:
How well are the Reader and base antenna adjusted to each other? A useful tool for evaluating the
adjustment of the antenna to the 50 Ω impedance is the VSWR meter. This device measures the
ratio between outgoing and reflected energy. A VSWR of up to 1.3:1 is considered a good value. A
wattmeter is often integrated into these devices.
Figure 10: Inserting a VSWR meter into the antenna cable
Reader
ID ISC.LR200-A
Base antenna
ID ISC.ANT800/600-A
Cable RG58 C/U
approx. 20 cm long
SWR / Power Mete
Antenna cable approx.
3.6 m long
The cable between the Reader and the SWR meter should either be very short (< 20 cm) or 7.20
m (RG 58=Lambda/2) long. If the VSWR is greater than 1.3:1 after tuning, use trim capacitors C1
and C2 to perform a slight adjustment.
Furthermore the VSWR meter can be used at any time to check the tuning of the base antennas. If
changes in local conditions result in detuning of the antennas, this can be verified whenever desired.
In addition to the losses indicated by the SWR due to mismatching between the cable and the antenna, it happens that the Reader drives different output currents depending on the antenna im-
pedance, resulting in power variance. This means that at 50 Ω a current of approx. 0.3 A flows. No
current flows when an output is open, and when there is a short circuit the current is limited to approx. 1.0 A. Matching the antenna also has a slight effect on the noise levels.
FEIG ELECTRONIC GmbH Page 23 of 33 N11000-2e-ID-B.doc
OBID® i-scan Application-Note ID ISC.ANT800/600
4. Startup and testing of the gate
After installing and calibrating the antennas, the correct function of the gate can be checked using
the Reader, the ISCStart service software (V4.00 or higher), a PC running under MS Windows, and
a Smart Label. The ISCStart software can be found on the
FEIG ELECTRONIC GmbH.
4.1. Reading out the serial number
Step Action Remarks
OBID
®
i-scan
CD-ROM supplied by
Attach a tag to one of the antennas
1
Click on Configuration
2
Set the label type in the configuration
3
block CFG3.
Set transponder parameters:
4
Configuration CFG8 General
Adhesive tape may be used
1 Set tag type
Configuration CFG3 RF-Interface I.
2 Save setting
Configure all transponder types to be
5
used for the desired mode.
Select Menu: “Test and Measure-
6
ments”
Select “ISO Inventory“ function
7
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Clock on “Start“ button
8
The serial number and tag type are
9
displayed in the window
4.2. Checking the Noise Level
Step Action: Remarks:
Select: “Test and Measurements“
1
menu
Select “Noise Levels“ function
2
Click on “Start“
3
Nominal values:
4
Average : 400 – 700 mV
Maximum – Minimum < 20 mV
If the nominal values are not maintained, check the following points:
• Are all cables firmly attached and making good contact ?
• Were the toroid cores installed on the antenna cable ?
• Were the cables routed properly ?
• Are other RFID devices installed in the area ?
• Are there large metal parts located in the vicinity of the antenna? ( < 1.0 m)
• Are there noise-generating devices nearby (larger machines or RF devices) ?
To determine which devices may be causing the disturbance, unplug them or power them down
one at a time.
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4.3. Setting the operating parameters
Step Action Remarks
1
2
3
4
Select Configuration menu
Configuration CFG3 RF-Interface:
Select 4 W RF power
Activate necessary transponder drivers.
Deactivate unused transponder drivers.
Set FSK-transponder, FSK-RX-CHN to
“0x02 both antennas“
Set transponder parameters:
Configuration CFG8 General
Configure all used transponder types to the
desired mode
5
6
7
8
9
Set new parameters in Reader
Select “Test and Measurements” menu
Select command: “ISO Inventory“
Start command: “ISO Inventory“
If the tag is placed in the antenna field, the
serial number and tag type will be displayed.
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4.4.Testing the performance
For this performance test we will be assuming the conditions described in the section: “Projecting
Notes“. The indicated ranges and read areas will change correspondingly when different labels are
used.
The test begins by checking the read range outside the gate (see illustration, points
assuming the configuration and local conditions permit. To begin, start the command ISO Inventory
in the ISCStart program (see points 6-9, section 4.3. ). Use a parallel label orientation with respect
to the antenna facing out. A read range of 60-65 cm (23.5 – 25.5 in) at should be achievable at the
centre of the antenna.
Figure 11: Testing the antenna with a label
Antenna 4
Antenna 2
c and d),
Antenna 3
Antenna 1
Now slowly move the label vertical and parallel orientation to the antenna inside the gate along the
e and f from as illustrated. The label should always be read.
line
Then repeat this on the line
Again the label should always be read.
The transition to Antenna 1 and 3 and Antenna 2 and 4 is critical. The lower point of capture at the
upper antenna must be at least a high as the upper capture point of the lower antenna.
If one or more “read holes“ are discovered, the base antenna should be adjusted to an impedance
of 50 Ω with the help of an SWR meter, and the noise levels on the Reader should be checked.
FEIG ELECTRONIC GmbH Page 27 of 33 N11000-2e-ID-B.doc
g in the gate center using the label oriented parallel to the antenna.
OBID® i-scan Application-Note ID ISC.ANT800/600
The following problems may arise:
• Antenna incorrectly installed (orientation, distance between antennas, check cable placement)
• Metal in the vicinity that detunes or disturbs the antennas
• One of the base antennas is improperly tuned (SWR ≥ 1.3)
• Noise is too high (Vmax – Vmin ≥ 20 mV)
• EMC toroid cores in the Reader or on the antenna cable are not properly installed.
• Label not sensitive enough, detuned or defective.
• Reader improperly configured (RF power, transponder type, modulation, transponder parame-
ters, etc.)
• Defective cable or connector making a poor contact.
• Reader, Transformer, Power Splitter or Antenna defective
4.5.Switching the Reader to Buffered Read Mode
“Buffered Read Mode“ is the normal operating mode for the Reader. This means the Reader reads
the tag data at maximum possible speed and stores the data in a ring buffer in the Reader.
Step Action Remarks
Select Configuration menu
1
Set Reader to
2
Buffered Read Mode.
(Also set Anticollision Select Mode)
Verify that the EEPROM is selected as
3
the destination memory
Save settings in the Reader with the
Write-Button
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4.6. Regulatory agencies in EU countries and the USA
The design and RF power of the antennas is affected mainly by the country-specific RF regulations. The entire EU geographic area is covered under uniform limits specified in the R&TTE
guideline and EN 300 330. In North America this is regulated by FCC Part 15.
In EU countries the maximum permissible field strength at 13.56 MHz at a distance of 10 m is:
42dBµA/m. In the USA this is 38dBµA/m.
When commissioning the system, be sure that the permissible values as prescribed by the national
regulatory agency are not exceeded.
Since FCC Part 15 prescribes a separation of 50 dB between the carrier and sidebands, the
Reader may be operated in the USA only using 1 of 256 bit coding (modulation).
When using Reader ID ISC.LR200-B and under optimum ambient conditions, the antennas can be
operated in the configuration as described here in EU countries using a maximum of 4 W, or 1.5 W
in the USA. If the limit values are higher or lower, the RF power must be adjusted accordingly or
the magnetic radiation needs to be reduced by shielding the antennas.
When commissioning the antennas, the system integrator should be sure that the installation instructions are followed, the necessary Reader settings have been made and that the limit values
prescribed by the national regulatory agency are not exceeded.
Furthermore the Reader must be configured as follows:
Parameter Europe USA
General
RF-Power – CFG 3 4 W 1.5 W
ISO15693 Label
Downlink RF Modulation – CFG
8 / ISO-MODE / MOD
Downlink RF Data coding –
CFG 8 / ISO-MODE / FAST
Timeslots - CFG 8 / ISO-MODE
/ NO-TS
Inventory Command Option –
CFG 8 / ISO-CMD-OPTION /
BREAK
10 % 10%
Fast (1/4) or Normal (1/256) Normal (1/256)
16 Timeslots 16 Timeslots
Complete Timeslot length at
“NO TAG“
Complete Timeslot length at
“NO TAG“
I-Code 1
Downlink RF Data coding –
CFG 8 / ICODE-MODE / FAST
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Fast Mode (1/1) or Normal
Mode (1/256)
- Normal Mode (1/256)
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(
)
4.7. Shielding around the antennas
To reduce the magnetic radiation of the gate antenna, a shield should be provided around the gate.
Each gate side should be shielded on four sides (back, right, left, up) at a distance of 50 cm to the
outer edge of the antennas.
Shielding may consist of metal plates or wire mesh up to a mesh size of 10 cm. The function of the
shielding should in all cases be checked using a suitable text fixture or in a testing laboratory.
Figure 12: Antennas with shielding, view from behind
50 cm
(19.7 in)
50 cm
19.7 in
25 cm (10 in)
Figure 13: View from above
50 cm
(19.7 in)
50 cm
(19.7 in)
50 cm
(19.7 in)
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5. Appendix: Helpful tools for constructing and testing the antennas
The following equipment is recommended for tuning, troubleshooting and commissioning the antennas:
• Laptop or personal computer (PC) running under Microsoft Windows 95, 98, ME, 2000, XP.
• Service software ISCStart (V4.02 or higher). This software can be found on the OBID® i-scan
CD-ROM supplied by FEIG ELECTRONIC GmbH..
• SWR and Power Meter including SMA connectors (female) or appropriate adapters.
• Qty. 1 cable RG 58 C/U approx. 20 – 25 cm (7.8 – 9.8 in) long with two male SMA plugs (gen-
erally self-assembled).
• Suitable screwdriver for antenna tuning, with plastic blade, 2.4x0.5mm.
• Dummy Load resistor 50 Ω with female SMA plug (or a PC Network dummy load 50 Ω with a
adapter to SMA)
ø 75
centre conductor
The following tools are optional but helpful:
• 2-channel oscilloscope, sweep rate at least 10ns/Div or analog bandwidth of 100 MHz.
• Qty. 2 test loops 1.5 m long (consisting of 50 Ohm, RG58 cable with BNC plug and wire loop
(diameter approx. 75 mm [30 in]) at the other end (generally self-assembled).
• HF Impedance Analyzer (for 13.56 MHz)
screen
BNC-plug, male
RG58 cable 2,5 m
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5.1. Recommended equipment and possible sources:
1. VSWR – Meter
Alan CTE International VSWR & Power – Meter KW 220
Vendors:
• CB Funkshop Rößner, 91637 Wörnitz, Tel.09868/932945, http://www.cb-funkshop.de
• Garant – Funk, 53879 Euskirchen, Tel. 02251/55757
Alan CTE International VSWR and Wattmeter K155
Vendor:
• Conrad Electronic
1. Antenna analyzer
MFJ HF/UHF SWR Analyzer
• Model MFJ-259B, 1.8 – 170 MHz
Vendors:
• Austin Amateur Radio Supply, USA 1-800 423 2604
• VHT – Impex, Ecke, Germany, Tel.: 05224/9709-0
CIA – HF Complex Impedance Analyzer 5012 – 5000
Vendors:
• AEA, Vista, California 92083, USA
• Garant – Funk, 53879 Euskirchen, Tel. 02251/55757
2. Adapter : UHF-> BNC, BNC-SMA, SMA-SMA, Abschlußwiderstand 50 Ω
Vendors:
• Bürklin OHG, http://www.buerklin.com
• Conrad.com AG, http://www.conrad.de
• Farnell Electronic Components GmbH, 82041 Oberhaching, http://www.farnell.com
3. Amber / Tuning screwdrivers with plastic blade
Blade size: 2,4x0,5mm
Vendors:
• Bürklin Bestellnummer 06 L 8364
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4. Oscilloscope
Tektronix TDS 210 or a model from the TDS2xx or TDS3xx. series
Agilent 54622D or a model from the 546xx series
Voltcraft 100 MHz- Oscilloskope 6100
Hameg HM 407 or HM 1507-3
Vendors:
• Tektronix Inc, http://www.tektronix.de oder http://www.tektronix.com
• Agilent Technoligies, http://www.agilent.com
• Conrad Electronic GmbH, 92240 Hirschau, http://www.conrad.de
• ELV Elektronik AG 26787 Leer, http://www.elv.de oder http://www.elv.com
• DataTec GmbH, 72770 Reutlingen, http://www.datatec.com
5.
EMC ferrite toroid cores
Diameter da=28, di=16, I=20, B.Nr.742 701 4
Diameter da=40,6 di=27,4 I=15, B.Nr.742 701 5
Vendor
Würth Elektronik GmbH & Co.KG
Riedenstraße 16
74635 Kupferzell
Tel.: 07944 / 91 93 0
www.wuerth.de oder www.wuerth.com
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