ID ISC.LRU3000 ID ISC.LRU3500

Transcription

1 APPLICATION-NOTE ID ISC.LRU3000 ID ISC.LRU3500 RSSI - Filter preliminary public (B) N e-ID-B.doc

2 Copyright 2011 by FEIG ELECTRONIC GmbH Lange Strasse 4 D Weilburg Tel.: Note With the edition of this document, all previous editions become void. Indications made in this manual 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 manual 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 manual 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 manual are based on advantageous boundary conditions. FEIG ELECTRONIC GmbH does not give any guarantee promise for perfect function in cross environments and does not give any guaranty for the functionality of the complete system which incorporates the subject of this document. FEIG ELECTRONIC call explicit attention that devices which are subject of this document are not designed with components and testing methods for a level of reliability suitable for use in or in connection with surgical implants or as critical components in any life support systems whose failure to perform can reasonably be expected to cause significant injury to a human. To avoid damage, injury, or death, the user or application designer must take reasonably prudent steps to protect against system failures. Use Exclusion in Transportation Market: Devices which are subject of this document may NOT be sold, used, leased, offer for sale, or otherwise transferred, exported, and imported by anyone in the Transportation Market. Transportation Market means (i) Electronic Toll and Traffic Management (ETTM), (ii) Public Sector Vehicle Registration, Inspection and Licensing Programs, (iii) Railroad Locomotive and Wagon tracking, (iv) airport based ground transportation management systems (GTMS) and taxi dispatch, (v) revenue based parking, and (vi) vehicle initiated mobile payment applications, where the RFID sticker/tag is initially attached to the vehicle but not incorporated at the point of vehicle manufacture. FEIG ELECTRONIC GmbH assumes no responsibility for the use of any information contained in this manual 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 and OBID i-scan are registered trademarks of FEIG ELECTRONIC GmbH. I-CODE is a registered trademark of Philips Electronics N.V. Tag-it TM is a registered trademark of Texas Instruments Incorporated. FEIG ELECTRONIC GmbH Page 2 N e-ID-B.doc

3 Contents 1. Abbreviated terms 4 2. Introduction 5 3. Configuration of the RSSI Filter CFG20: RF-Parameter Diagnostic LEDs 8 5. Measurements 9 FEIG ELECTRONIC GmbH Page 3 N e-ID-B.doc

4 1. Abbreviated terms ANT CFG e.r.p. RFID RSSI UHF Antenna Configuration Parameter Block Effective Radiated Power Radio-Frequency Identification Received Signal Strength Indication Ultra High Frequency FEIG ELECTRONIC GmbH Page 4 N e-ID-B.doc

5 2. Introduction The received signal strength indicator (RSSI) is a measurement of the power present in a received transponder response. The following document describes in which way a filter can be activated that only transponders will be reported by the interrogator whose signal strength is above a defined limit. FEIG ELECTRONIC GmbH Page 5 N e-ID-B.doc

6 3. Configuration of the RSSI Filter The RSSI Filter can be activated and configured in CFG20 Byte 0 of the reader configuration. A configuration with ISO Start needs to be done manually in the Byte block. There is no special parameter visible in ISO Start CFG20: RF-Parameter The parameters of the CFG20 configuration block contain the antenna gain setting. Byte Contents RSSI-Filter 0x00 0x00 0x00 0x00 0x00 0x00 Default 0x00 Byte Contents 0x00 0x00 0x00 RF-POWER- ANT2 RF-POWER- ANT3 RF-POWER- ANT4 Default 0x19 0x19 0x19 0x00 RSSI-Filter: (AirInterface.Antenna.UHF.RSSI-Filter) Defines the RSSI Filter Level Bit: Function Filter Level Filter-Level Level of the RSSI-Filter Filter-Level 0x00 0x01 0x02 0x03 0x04 0x05 0x06 0x07 0x08 0x09 0x0A 0x0B 0x0C 0x0D 0x0E 0x0F 0x10 0xFF Level No Filtering -1 dbm -2 dbm -3 dbm -4 dbm -5 dbm -6 dbm -7 dbm -8 dbm -9 dbm -10 dbm -11 dbm -12 dbm -13 dbm -14 dbm -15 dbm -16 dbm - dbm -255 dbm FEIG ELECTRONIC GmbH Page 6 N e-ID-B.doc

7 Note: Only Transponders will be displayed whose received signal strength is above the defined Filter Level. The defined Filter Level is applicable for all antenna ports. Typically a transponder on the surface of the antenna is responding with a signal strength below -15 dbm. A description of the other parameters of this configuration block can be found in the system manual H90202-xe-ID-B.pdf of the reader. FEIG ELECTRONIC GmbH Page 7 N e-ID-B.doc

8 4. Diagnostic LEDs To signalize the presence of a transponder below the defined Filter-Level the diagnostic LED of the antenna port on which the tag was detected will turn on violet. ANT1 ANT2 ANT3 ANT4 Fig. 1: Diagnostic LEDs ANT1: Blue All detected transponders are responding above the defined Filter-Level ANT2: Violet At least one detected transponder is responding below the defined Filter Level ANT3: Green Antenna active but no transponder in reader field ANT4: Red RF-Warning, Antenna failure FEIG ELECTRONIC GmbH Page 8 N e-ID-B.doc

9 5. Measurements The following diagrams show the RSSI value of a transponder response in a certain distance of the reader antenna. All measurements were taken into an absorber chamber. The reader setup and reader antenna setup was not changed during all the measurements. All changes were made to the transponder. Used Equipment: Reader: ID ISC.LRU3500-EU Antenna: ID ISC.ANT.U270/270-EU Antenna cable: Belden H155, 6m Radiated Power: 2 Watts e.r.p. The RSSI value is only applicable if all transponders have the same chip inside. Fig. 2: different chip, same orientation, same transponder antenna design FEIG ELECTRONIC GmbH Page 9 N e-ID-B.doc

10 The RSSI value is only applicable if all transponders have the same orientation towards the antenna. Fig. 3: same chip, different orientation, same transponder antenna design The RSSI value is only applicable if all transponders have the same antenna design. Fig. 4: same chip, same orientation, different transponder antenna design FEIG ELECTRONIC GmbH Page 10 N e-ID-B.doc

11 The RSSI value is only applicable in short distance of the antenna (max. 2,5m). Reflections will additionally falsify the RSSI value Fig. 5: Same RSSI value appears in different distances FEIG ELECTRONIC GmbH Page 11 N e-ID-B.doc