CAEN RFID API User Manual
Contents
1. Kill Acces EPC in User Kill Acces EPC TID User Mask Mask Mask Mask Mask Act Act Act Act Act I HE fu MARES EU ee SES ae a8 Ww i i E WE A _ ty G RO 9 2 o _ Non permanent locking of User Memory Bank int Payload 0x00802 MySource LockTag EPC C1G2 MyTags i Payload Console WriteLine Press a key to end the program Console ReadKey MyReader Disconnect LockTag_EPC_C1G2 method is a member of the CAENRFIDLogicalSource class Killing Gen2 tags 20 The EPCGlobal Class1 Gen2 protocol provides a way to kill tags that means tags after the kill process are no more readable This process is password protected you can kill only tags with a non zero kill password So once you have set the kill password using the WriteTag_EPC_C1G2 method on the RESERVED memory bank at address 0 you can use the KillTag_EPC_C1G2 method of the CAENRFIDLogicalSource class to kill the tag The tag that has to be killed is selected just by matching the complete EPC along with the Kill Password Differently from the previously described methods t2. E RA dada aaa 5 2 Getting Started ao taaan tia 7 3 Basic Operations nt inner n te Nid 9 Importing the libraries vce cic ees bse us A AA RM nt RE a di ia e iad e 10 Reader connection discONNECtiON nninnnnnnnnnnnnnnnnnnnnnnnnnnnnrr rara 10 Getting information about the connected reader 10 Setting the powerlevel z Arant esse ss nn ere ne ete ne Are en es RER ds 11 Inv ntorving REID tagS sr nn nn A dd ein ascenseur eet de ur e aan cas de ho vets a cases chy veces tos Lan cheat ten 12 Optimizing the inventory PrOCes cceceeesssscccceeessessneeeeececesseeseeeeeceeseeeeeeeeeeeeesseeeesaeeeeeeeseseesaseeeeeeeeseeeeaaaeeeees 13 TheQ A xido 13 SESION Spira A A nn en tn te 15 Reading andiwriting Gen2 tags iia tele A AA AAA AAA AAA 17 ATA O OT 19 ATA A RO 20 Handling General purpose Inputs Ouputs GPIOS iii 21 List of Tables Tab 3 1 Recommended Q Values ccoocccnncccnncncnncncnncnnnnaconnanonnanonnncnnnaconnanonnanonnarc ona nana no nnana nara n nara nnanannanannns 13 SA AA O A ES SE E 15 Tab 3 3 LOCK PAYO NU oi t E es 19 Tab 3 4 Lock ACHONn fleld functionality 0 A ES UE 19 CAEN FID Introduction This Chapter gives basic information about the SDK architecture It contains these topics e Overview e SDK Design Concepts 4 CAEN RFID API User Manual CAENAFID Overview This guide describes the model design concepts and the Application Software Interface API offered by CAEN RFI
3. The reader accepts commands coming from an host a PC or any other controlling device it uses the interface to the tag typically one or more antennas to perform operations on the tags and it replies to the host HOST HOST INTERFACE READER TAG INTERFACE TAG The API defines a number of classes emulated in C language by functions and data types in order to represent this simplified model two of them define most of the methods and can be considered the core classes of the API itself CAENRFIDReader and CAENRFIDLogicalSource CAENRFIDReader class provides methods for the general reader configuration host communication interfaces configuration HW parameters etc CAENRFIDLogicalSource class defines the methods for the reader to tag communication and its configuration Working with the host interfaces mostly represented in the CAENRFIDReader class is quite straightforward since they are standard communication interfaces Ethernet RS232 and similar while for the CAENRFIDLogicalSource class a deeper insight is needed One or more physical RFID antennas called ReadPoints in the API can be connected to a CAEN RFID each one able to detect tags and it is typical in UHF RFID installations to place multiple antennas in the same place for a better coverage of the reading area In this case even if multiple antennas are used the reading area is the same so from a logical point of view it is a single source of homogeneous information I
4. enabled default behavior all the tags collected during the inventory process are stored into the reader s memory and returned back to the user at the end of the process With the framed mode enabled as soon as a tag is detected is returned immediately to the user This behavior results in a better responsiveness of the application especially with large population of tags and it is suggested when a small embedded reader with limited memory is used It is mandatory to enable the framed bit when the continuous mode is enabled see next bit description Bit 2 enables 1 or disables 0 the continuous mode when this bit is enabled the reader implements internally a cycle of inventories The number of executed inventories is determined by the ReadCycle parameter that can be set with the SetReadCycle method of the CAENRFIDLogicalSource class When ReadCycle is O the cycle is repeated indefinitely until an abort command is sent to the reader Bit 3 enables 1 or disable 0 the compact data mode when this flag is enabled the inventory method will return back to the caller only the EPC code of the tag and all the other information like the timestamp and the type of the tag are filled with fake values This flag is useful when it is necessary to reduce the data exchanged on the host interface typically when the interface is slow low baud rate serial interfaces Bit 4 enables 1 or disables 0 the readout of the TID during the inventory process A fur
5. namespace ConsoleApplicationl class Program static void Main string args CAENRFIDReader MyReader new CAENRFIDReader MyReader Connect CAENRFIDPort CAENRFID RS232 COM3 CAENRF U LogicalSource MySource MyReader GetSource Source 0 MySource SetQ EPC C1G2 3 CAENRFIDTag MyTags MySource InventoryTag if MyTags Length gt 0 for int i 0 i lt MyTags Length itt String s BitConverter ToString MyTags i GetId Console WriteLine s Console WriteLine Press a key to end the program Console ReadKey MyReader Disconnect SetQ_EPC_C1G2 and GetQ_EPC_C1G2 methods are members of the CAENRFIDLogicalSource class CAEN RFID API User Manual CAENRFID Sessions When a tag is singulated by the slotted ALOHA algorithm described in the previous paragraph it switches automatically from an internal state A to another internal state B In the EPC C1G2 terminology these states are called target A and target B respectively for our purposes we can refer to target A as the non inventoried state and to target B as the inventoried state singulation makes therefore switch a tag from the non inventoried state to the inventoried state By default CAEN RFID readers looks for non inventoried tags so once a tag has been inventoried it is no more detectable by the reader until it returns back in the non inventoried state Tags retu
6. operate with a CAEN RFID reader using the API CAEN RFID API User Manual 7 CAENAFID The minimum steps a programmer should follow in order to operate with a CAEN RFID reader using the API are the following Open a connection with the reader Configuration of the logical source optional if the default configuration is fine Detection of tags and other operations on the tags Close the connection with the reader Here below a simple but complete code snippet showing the minimum required lines of code to detect RFID tags using a CAEN RFID reader and the CAEN RFID API The code is shown using NET C programming language but it can be easily adapted to the other languages supported by the API using System using System Collections Generic using System Linqg using System Text using com caen RFIDLibrary namespace ConsoleApplicationl class Program static void Main string args CAENRFIDReader MyReader new CAENRFIDReader MyReader Connect CAENRFIDPort CAENRFID RS232 COM3 CAENRFIDLogicalSource MySource MyReader GetSource Source 0 CAENRFIDTag MyTags MySource InventoryTag if MyTags Length gt 0 i fork GOME NO EU VIT IS Lengeh IEE String s BitConverter ToString MyTags i Getld Console WriteLine s Console WriteLine Press a key to end the program Console ReadKey MyReader Disconnect 7 CAEN RFID API User Manual CAENRFID Ba
7. 3 hex format MyReader SetIODirection MyDirections Coming to the GetlO and SetlO methods we can get GPIO s input status and set GPIOs output status as follows int InputVal 0x0 int OutputVal 0x2 GPIOO output value 0 GPIO1 output value 1 MyReader GetI0O amp InputVal MyReader SetI0O OutputVal CAEN RFID API User Manual 21
8. 5 of the FCC Rules Operation is subject to the following conditions 1 this device may not cause harmful interference and 2 this device must accept any interference received including interference that may cause undesired operation These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment This device generates uses and can radiate radio frequency energy If not installed and used in accordance with the instruction manual the product may cause harmful interference to radio communications Operation of this product in a residential area is likely to cause harmful interference in which case the user is required to correct the interference at their own expense The authority to operate this product is conditioned by the requirements that no modifications be made to the equipment unless the changes or modifications are expressly approved by CAEN RFID This declaration only applies to FCC readers A828US A829US A528 R1230CB R12601 R260U R4300P A528B Index Scope Of MANUAL Bi di A A A a TA a RT bike 2 Change Document Record REEE ideada cdi lirica 2 Md ii 3 List OF TADIOS iiss cscessctcccennssscessetcaeenssdsseestecateusedseoesccadeavosandeosss cusaawosedaevesscedeawescdansvsdcedenueccssuaveseateous 3 T Introductions NT 4 OVINA Penn PA etes re OR ete se 5 SDK DESIBN CONCEDES vuitton intacta entrants Mate ira sde eines needs te datent es
9. CAEN RFID API User Manual User Manual Le 02 05 2013 CAENAFID Scope of Manual The goal of this user manual is to provide the basic information to work with CAEN RFID readers The CAENRFID is a basic library to support an easy communication with different reader types Change Document Record Date Revision Changes Pages 14 Jul 2010 01 Initial release 14 Jan 2011 02 Added Federal Communications Commission FCC Notice 2 20 Sep 2012 03 Added R4300P Reader in the Federal Communications 2 Commission FCC Notice 02 May 2013 04 Added A528B Reader in the Federal Communications 2 Commission FCC Notice CAEN RFID srl Via Vetraia 11 55049 Viareggio LU ITALY Tel 39 0584 388 398 Fax 39 0584 388 959 info caenrfid it www caenrfid it CAEN RFID srl 2010 Disclaimer No part of this manual may be reproduced in any form or by any means electronic mechanical recording or otherwise without the prior written permission of CAEN RFID The information contained herein has been carefully checked and is believed to be accurate however no responsibility is assumed for inaccuracies CAEN RFID reserves the right to modify its products specifications without giving any notice for up to date information please visit www caenrfid it Federal Communications Commission FCC Notice Preliminary 7 This device was tested and found to comply with the limits set forth in Part 1
10. Connect CAENRFIDPort CAENRFID RS232 COM3 CAENRFIDLogicalSource MySource MyReader GetSource Source 0 CAENRFIDTag MyTags MySource InventoryTag j if MyTags Length gt 0 for int i 0 i lt MyTags Length i String EPCString BitConverter ToString MyTags i Getld Console WriteLine EPCString byte DataToWrite ASCIIEncoding Enc new ASCIIEncoding DataToWrite Enc GetBytes Hello MySource WriteTagData_EPC_C1G2 MyTags i 3 0 6 DataToWrite Console WriteLine Tag written byte DataToRead DataToRead MySource ReadTagData_EPC_C1G2 MyTags i 3 0 6 Console WriteLine Tag read value Enc GetString DataToRead Console WriteLine Press a key to end the program Console ReadKey MyReader Disconnect The read or write command will be executed on the first tag that replies to the reader chosen from those matching the filtering criterion ReadTag_EPC_C1G2 and WriteTag_EPC_C1G2 methods are members of the CAENRFIDLogicalSource class CAEN RFID API User Manual CAENRFID Locking Gen2 tags The EPCGlobal Class1 Gen2 protocol provides a mechanism to lock temporarily or permanently blocks of tag s memory The user can lock an entire memory bank with the only exception of the Reserved memory bank where it is allowed to lock independently the Access Password and the Kill Password The lock mechanism prevents the possibility of further modification
11. D for the development of software for use integrate and control CAEN RFID readers and accessories CAEN RFID provides a Software Development Kit SDK that includes APIs for the most common programming languages Java NET CH and Visual Basic and Visual C C In details the SDK package contains e a NET library in the form of a DLL file with its own history file the help file CHM format the NET CF Compact Framework version and a demo application with source code e a Java library in the form of a JAR file with its own history file the corresponding JavaDoc files HTML format and a demo application with source code e a Visual C library in the form of a DLL file with its own history file the stub file lib the headers and a demo application with source code e the CAEN RFID API User Manual this document e the CAEN RFID API Reference Manual The differences between the APIs are mostly related to the different language syntax and architecture but from a semantic point of view the methods functions are maintained the same in all the languages CAEN RFID provides also the complete documentation of the raw binary protocol that can be used to communicate with CAEN RFID readers for languages or architectures not supported by the APIs SDK Design Concepts A CAEN RFID reader can be seen in a simplified model as a box with one or more communication interfaces on the host s side and one or more antennas on the tags side
12. aneously present in the reading zone A few tags require only a few slots whereas many tags require many slots Left to its own the reader doesn t have any way of knowing how many tags are under the antenna s field until it counts them which may be difficult if its initial guess is wildly wrong CAEN RFID reader will work faster and more efficiently if you provide an accurate starting value for Q corresponding to the expected tag population the more are the collisions the worse are the performance of the reader in detecting the tags The detection method implemented inside CAEN RFID readers has also an auto adaptive mechanism in order to generate more or less time slots when needed but starting with an adequate number of time slots helps this mechaism to avoid wasting time For reference the following table gives recommended values of Q that produce reasonably efficient inventories for varying numbers of tags in the read zone 1 0 2 1 3 6 2 7 15 3 16 30 4 30 50 5 50 100 6 100 200 7 Tab 3 1 Recommended Q values CAEN RFID API provides the methods to set and read back the starting Q value SetQ_EPC_C1G2 and GetQ_EPC_C1G2 CAEN RFID API User Manual 13 14 CAENAFID Here below a code sample where the Q value is set to 3 before to start the inventory process using System using System Collections Generic using System Linqg using System Text using com caen RFIDLibrary
13. ation about the connected reader are shown CAENRFIDReaderInfo Info MyReader GetReaderInfo String Model Info GetModel String SerialNumber Info GetSerialNumber String FWRelease MyReader GetFWRelease GetReaderlnfo and GetFWRelease methods are members of the CAENRFIDReader class 10 CAEN RFID API User Manual CAEN FID Setting the power level Most of the CAEN RFID readers allow to regulate the emitted power This setting is useful in order to limit the read range of the reader to limit the power as stated by the local regulations or for adapt the power depending on the antenna characteristics The API provides two methods one for setting the power SetPower and one for getting the current power level GetPower The value passed to SetPower and returned by GetPower is expressed in milliWatt mW and refers to the power generated by the reader at the antenna s connectors The effective radiate power in mW ERP Perp is related to the conducted RF power Pw provided at the reader s connector by the following formula Perp G22 14 1 10 10 Pw where G is the antenna gain expressed in dBi and L the cable attenuation expressed in dB So if you require as often is to set a ERP power level the above formula has to be implemented in your software in order to obtain the conducted RF power Here below a code example that permits to obtain the desired ERP power from the antenna using the above formu
14. ently readable and writeable from either the open or secured states and may never be locked 1 0 Associated password location is readable and writeable from secured state but not from open state 1 1 Associated password location is not readable or writeable from any state Tab 3 4 Lock Action field functionality The CAEN RFID API provides a method LockTag_EPC_C1G2 to lock the tag s memory contents that mimic exactly the behaviour of the protocol command The payload parameter is implemented as a bitmask with the meaning described by the above tables The API provides also the secured version of the LockTag_EPC_C1G2 method to be used when the Access password is set CAEN RFID API User Manual using using using using using CAEN FID Here below a code example of the LockTag_EPC_C1G2 method utilization System System Collections Generic System Ling System Text com caen RFIDLibrary namespace ConsoleApplicationl elass Progren static void Main string args CAENRFIDReader MyReader new CAENRFIDReader MyReader Connect CAENRFIDPort CAENRFID RS232 COM3 CAENRFIDLogicalSource MySource MyReader GetSource Source 0 CAENRFIDTag MyTags MySource InventoryTag if MyTags Length gt 0 for int i 0 i lt MyTags Length i String EPCString BitConverter ToString MyTags i Getld Console WriteLine EPCString
15. er Connect CAENRFIDPort CAENRFID RS232 COM3 CAENRF U LogicalSource MySource MyReader GetSource Source 0 MySource SetSession EPC_C1G2 CAENRFIDLogicalSourceConstants EPC_C1G2 SESSION S1 CAENRFIDTag MyTags MySource InventoryTag if MyTags Length gt 0 for int i 0 i lt MyTags Length itt String s BitConverter ToString MyTags i GetId Console WriteLine s Console WriteLine Press a key to end the program Console ReadKey MyReader Disconnect SetSession_EPC_C1G2 and GetSession_EPC_C1G2 methods are members of the CAENRFIDLogicalSource class CAEN RFID API User Manual CAENAFID Reading and writing Gen2 tags Gen2 tags contains a memory with the following structure MSB LSB TID 15 00 TID 31 16 Bank 11 EPC 15 0 Bank 10 EPC N N 15 PC 15 00 CRC 16 15 00 Bank 01 Bank 00 RESERVED Access Passwd 15 00 3Fh Access Passwd 31 16 2Fh Kill Passwd 15 00 1F 20h Kill Passwd 31 16 OF The inventory process returns the EPC code that is part of the content of the EPC memory bank as a side effect of the singulation process All the memory content anyway can be read using the Gen2 Read command and the rewritable memory can be written using the Gen2 Write command The CAEN RFID API provides methods to read ReadTag_EPC_C1G2 and write WriteTag_EPC_C1G2 data into the tags memory the methods imp
16. here is not a secured version of the kill method since the kill command is always protected by a specialized kill password CAEN RFID API User Manual CAENFID Handling General purpose Inputs Ouputs GPIOs Almost all CAEN RFID readers are provided along with some programmable GPIOs for further details on GPIOs for a specific CAEN reader please refer to the correspondent reader s manual On each GPIO you can perform two basic operations e Selects its direction INPUT OUTPUT e Sets its value HIGH LOW GPIO direction can be set and read by means of a 4 byte long bitmask used in conjunction with the Get ODirection and SetlODirection methods Each bit in the bitmask represents the GPIO direction a 0 value means INPUT a 1 value means OUTPUT A 4 byte long bitmask in conjunction with GetlO and SetlO functions is also used to set get GPIO s OUTPUT INPUT values e Each upset bit in the bitmask sets the correspondent GPIO to a HIGH logic voltage e Each cleared bit in the bitmask sets the correspondent GPIO to a LOW level voltage High and low voltage value varies with the specific CAEN s reader used Please refer to the specific CAEN reader s manual to know the effective voltage values adopted Let s suppose we have a reader with 4 GPIOs available and we want to program GPIOO GPIO1 as OUTPUT and GPIO2 GPIO3 as INPUT the bitmask associated to this settings is 0000 0011b and the code is as follows int MyDirections 0x
17. la and the SetPower method double Gain 8 0 double Loss 1 5 double ERPPower 2000 0 int OutPower OutPower int ERPPower Math Pow 10 Gain Loss 2 14 10 MyReader SetPower OutPower and here a code example that permits to know the current setting of the ERP power using the inverse form of the formula and the GetPower method double Gain double Loss double ERPPowe int OutPower 0 oF H 0 7 OutPower MyReader GetPower ERPPower double power double Math Pow 10 Gain Loss 2 14 10 Typically CAEN RFID readers approximate automatically the power to the nearest available power level and the same is done for the minimum and maximum power level For the available power levels please refer to the reader s user manual There could be a difference between the power level set and the power level read just after the setting this effect is normal and it is due to one or more of the following reasons e the set value was not exaclty one of the available power level on the reader so the real power level is the nearest available e the formula used to convert ERP to conducted power introduced a mathematical approximation e on some CAEN RFID readers the value returned by the GetPower method is a measurement of the power that can be affected by the accuracy of the measurement and the caracteristics of the connected antenna GetPower and SetPower methods are members of the CAENRFIDReader c
18. lass CAEN RFID API User Manual 11 CAEN FID Inventorying RFID tags 12 The fundamental operation of a UHF RFID system is the inventory of the population of tags inside the reading zone of the reader s antennas This operation for the Gen2 protocol as for other UHF protocols consists of a sequence of commands and replies exchanged between the reader and the tags typically with stringent timings between them CAEN RFID readers hide the complexity of the inventory algorithm implementing the algorithm in the firmware and providing a macro command as interface for the user The CAEN RFID API provides methods in order to activate the inventory process the simplest method that just tries to collect all the tags inside the reading zone a more complex one with a list of options and a method to start a cycle of inventories In the simplest form the inventory process can be activated simply by calling the InventoryTag method of the CAENRFIDLogicalSource class This method has no parameters at all and returns an array of CAENRFIDTag objects once a complete run of the inventory algorithm is performed inside the reader a CAENRFIDTag object is a software representation of the physical tag carrying the data associated to it like the EPC code its length the type of the tag and others For a code sample look at the Getting Started pag 8 of this manual A more complete version of the InventoryTag methods takes parameters for filtering tags and to ac
19. lement internally a Select command that is used to identify the tag on which execute the read or write command permitting to read write into a specific tag even if multiple tags are inside the reading zone The identification of the tag is executed by matching the EPC code that can be previously obtained by an inventory process The other parameters needed to execute the read and write command are the memory bank the starting address the data length and in case of the write command the data that have to be written The API provides also a secured version of those commands that require a password as an additional parameter These variants of the methods have to be used in the case the Access password is set into the tag Tags with a non zero Access password are protected in Gen2 terminology tags with a non zero Access password are in Open state and the user needs to know and passes to the tag the Access password in order to write into the tag s memory in Gen2 terminology the tag has to switch in Secured state using the password before to allow to write CAEN RFID API User Manual 17 CAEN FID Here below a code sample of reading writing data from to the user memory using System using System Collections Generic using System Linq using System Text using com caen RFIDLibrary namespace ConsoleApplicationl class Program static void Main string args CAENRFIDReader MyReader new CAENRFIDReader MyReader
20. n order to model this concept we introduced the Logical Source concept that is implemented into the CAEN RFID API with the CAENRFIDLogicalSource class it permits to group together ReadPoints antennas that are logically related Each data exchange concerning tags is implemented through the CAENRFIDLogicalSource class the case of a single antenna is a special case where a Logical Source contains a single Read Point The CAEN RFID API permits to add and remove Read Points to from the Logical Source so that the user can easily represent its installation CAEN RFID API User Manual 5 CAEN FID Up to the current revision the API handles four Logical Source called Source_0 Source_1 Source_2 Source_3 and four Read Points called Ant0 Ant1 Ant2 Ant3 and the default configuration is that each LogicalSource contains only one different ReadPoint in the future this could change and the number of Logical Sources and Read Points could be different depending on the model of the RFID reader On readers with a single antenna connector the only meaningful Logical Source is the Source_0 one and it contains the only one available antenna Ant0 Note that after a reader switch off the Logical Sources composition is reset to the default configuration CAEN RFID API User Manual CAENRFID Getting Started This chapter describes the minimum steps a programmer should follow in order to
21. rn in the non inventoried state autonomously and the times needed to return detectable can be regulated using the session parameter This tuning can have a big impact on the inventory process performances especially in case of large tags population Gen2 protocol provides four different sessions SO S1 S2 S3 Each session has its own independent inventoried and non inventoried states with its specific persistence time as shown in the following table Tag energized Indefinite Tag not energized None Tag energized Nominal temperature range 500ms lt persistence lt 5s Extended temperature range Not specified Tag not energized Nominal temperature range 500ms lt persistence lt 5s Extended temperature range Not specified Tag energized Indefinite Tag not energized Nominal temperature range 2s lt persistence Extended temperature range Not specified Tag energized Indefinite Tag not energized Nominal temperature range 2s lt persistence Extended temperature range Not specified SO inventoried flag S1 inventoried flag S2 inventoried flag S3 inventoried flag Tab 3 2 Persistence Time When session SO is used each time the reader switches off the radiofrequency field the tags return back in the original not inventoried status so that they are again detectable with a successive inventory algorithm round Since CAEN RFID readers switch off the field at the end of each inventory round all the tag
22. s are detected again each time the inventory is repeated This behavior can be desirable for testing purposes or when a certain level of redundancy is needed but it is typically not efficient and generate a lot of useless information With session S1 the tags once singulated remain in the inventoried state for a time in the range between 500ms and 5s regardless if the tag is energized or not during this period they are no more detectable by the subsequent inventory iterations On large tags populations this behavior helps to reduce the number of tags simultaneously detectable by the reader optimizing the speed of the inventory process and reducing the generated data Sessions S2 and S3 have a longer and not explicitly limited persistence time giving the opportunity to detect tags only one time during the inventory process repetitions These sessions are for advanced use only and are out of the scope of this manual CAEN RFID API provides the methods to set and read back the session parameter SetSession_EPC_C1G2 and GetSession_EPC_C1G2 CAEN RFID API User Manual 15 16 CAENAFID Here below a code sample where the session S1 is used during the inventory process using System using System Collections Generic using System Linqg using System Text using com caen RFIDLibrary namespace ConsoleApplicationl class Program static void Main string args CAENRFIDReader MyReader new CAENRFIDReader MyRead
23. s on locked memory banks and only for the passwords in the Reserved memory bank it prevents also the possibility to read back the data the passwords The lock command works with a single parameter called payload that includes both the lock s type permanent or not and the bank to lock The format of the payload is described by the following tables Lock Command Payload ODO ION DIE 1 SOON Kill Mask Mask Action Tab 3 3 Lock payload and usage Access Mask be ee User Action Access Action User Kill Mask Action Pale Pian Masks and Associated Action Fields 0 1 2 3 4 5 6 7 8 9 skip skip skip skip skip skip skip skip skip skip write write write write write write write write write write 10 11 12 13 14 15 16 17 18 19 pwd pwd perma perma pwd perma pwd perma pwd perma read read lock lock write lock write lock write lock write write Associated memory bank is writeable from either the open or secured states Associated memory bank is permanently writeable from either the open or 0 1 secured states and may never be locked 1 0 Associated memory bank is writeable from the secured state but not from the open state 1 1 Associated memory bank is not writeable from any state Associated password location is readable and writeable from either the 0 0 open or secured states 0 1 Associated password location is perman
24. sic Operations This chapter shows the most common operations that a programmer can perform using a CAEN RFID reader and the CAEN RFID API All the example will be shown in the CH language the Visual Basic Java and C version are omitted since they differ only at syntax level The chapter contains these topics e Importing the libraries Reader connection disconnection e Getting information about the connected reader e Setting the power level e Inventorying RFID tags e Optimizing the inventory process e Reading and writing Gen2 tags e Locking Gen2 tags e Killing Gen2 tags e Handling General purpose Inputs Ouputs GPIOs CAEN RFID API User Manual 9 CAEN FID Importing the libraries The current version of Net and Visual C libraries have been developed using Microsoft Visual Studio 2005 and the Java library has been developed using Oracle Netbeans 6 8 Methods to import the libraries in the application developer s projects strongly depend on the Integrated Development Environment IDE please refer to the documentation of the IDE in use for instructions Reader connection disconnection The first operation to perform in order to start to operate with CAEN RFID readers is to establish a connection The connection method depends on the physical interface available on the readers that at now could be an Ethernet or a serial interface Readers with USB interface can be considered as having a standard RS232 serial interface
25. since the readers implement a USB to RS232 converter internally The API provides the Connect method function that permits to establish the connection The method accepts two parameters the interface type and the address If the interface type is serial the address will be the name of the serial port e g COM1 if the interface is Ethernet TCP IP the address will be the IP address of the reader Here below code examples for serial port connection and for TCP IP connection are shown MyReader Connect CAENRFIDPort RS232 COM1 MyReader Connect CAENRFIDPort TCP 192 168 0 2 Once connected it is possible to operate on the reader with the other methods At the end of the operations it is possible to disconnect from the reader using the Disconnect method function MyReader Disconnect Connect and Disconnect methods are members of the CAENRFIDReader class Getting information about the connected reader The same API can be used to control different type of readers with different capabilities It is often useful to know which type of reader is connected to the application in order to access to the right features The API provides two methods for getting information about the connected reader GetReaderinfo and GetFWRelease The first returns information about the reader s model and serial number the latter returns the version of the firmware running into the reader itself Here below code examples for getting inform
26. ther option is to use an event based inventory handling that means start a continuous and autonomous inventorying getting immediately the control of the thread flow to the caller All the readings will be received by the application as software events The user needs to define an event handler that will take care of handling the data coming from the tags InventoryTag EventinventoryTag and InventoryAbort methods are members of the CAENRFIDLogicalSource class CAEN RFID API User Manual CAENAFID Optimizing the inventory process EPC Class1 Gen2 protocol defines a set of parameters useful for the optimization of the tags detection in the current paragraph we give a brief explanation of the most useful ones and we show how to work with those parameters using the CAEN RFID API The Q parameter The Gen2 protocol inventory method is based on the so called Slotted ALOHA algorithm without going into the details of the algorithm it is important to know that it foresees a division of the time in discrete slots Only one tag can be detected for each slot if two or more tags reply on the same slot a collision is generated and the tags are not detected so a further iterations of the algorithm is needed The number of time slots is defined in the Gen2 protocol as 2Q where Q is a parameter ranging from O to 15 that can be set by the user The optimal Q value for a certain application is related to the average number of tags that are simult
27. tivate some optional features The parameters used to filter the tags that have to be detected are the memory bank Bank the mask Mask the length of the mask MaskLength and the start address Position for the matching Using those parameters a Gen2 Select command is issued before starting the inventory process in order to match only the interesting tags In the matching process the Mask parameter is compared to the memory bank content starting from the address Position for MaskLength bits Only the matching tags will be involved in the inventory process and returned back to the user by the nventoryTag method The user can also choose the result of the matching mechanism i e can choose to return the matching tags the not matching tags or all the tags ignoring indeed the filter This setting can be changed using the SetSelected_EPC_C1G2 method of the CAENRFIDLogicalSource class possible values for its only parameter are e EPC C1G2 SELECTED YES for matching tags e EPC_C1G2 SELECTED NO for non matching tags e EPC C1G2 SELECTED ALL for all tags no filter An additional parameter Flags permits to activate special features of the inventory process it is a bit mask where only the 5 less significant bits are used Bit 0 enables 1 or disables 0 the Return Signal Strength Indicator RSSI reading for each tag for those readers supporting it Bit 1 enables 1 or disables 0 the so called framed mode if the framed mode is not
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