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General General (12)
Software/Firmware Software/Firmware (6)
Hardware Hardware (2)
  • General
  • Q. Can I switch on/off the antennas in a selective way ?
    A. Yes, you can do it either using our demo applications or developing your own application using the API we provide (please refer to the API manuals for further details).
  • Q. Can I program an EPC Class1 Gen2 tag with a proprietary code numbering ?
    A. Yes, you can: the EPC memory bank of EPC Class1 Gen2 tags can be programmed with any code. By the way, before implementing a proprietary RFID coding scheme, consider implementing one of the EPC standards as defined in the EPCglobal EPC Tag Data Standard to make your implementation scalable for future use in a standard RFID system. If you decide not to implement one of the EPC standards with UHF tags, try including a header field of 8 bits of all zeros in your tag because this is not a valid EPC header and it should insure your tags do not conflict in some way with other EPC or DOD tags.
  • Q. What is the difference between a linear polarized and a circular polarized antenna ?
    A. Electric and magnetic fields radiated by linear polarized antenna are oriented along only one direction, on the contrary for circular polarized antenna EM fields rotate by tracing a circle perpendicular to the propagation direction. A RFID tag is usually linear polarized so, with a linear polarized reader antenna, the tag must be oriented in the same direction of the reader antenna. With a circular polarized reader antenna, the tag can be oriented in any direction with respect to the reader antenna, even if only half of the radiated power density will be received by the tag. For this reason, with the same conducted input power, the ERP (Effective Radiated Power) of a circular polarized antenna is 3dB lower than the ERP of a linear polarized antenna that has the same gain (expressed in dBi).
  • Q. What is the relation between the radiate and conducted output power according to the antenna gain and the cable loss ?
    A. 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:

    where G is the antenna Gain expressed in dBi (for linear antennas) or dBic (for circular antennas) and L the cable attenuation expressed in dB.

  • Q. What is the reading range of your readers ?
    A. There is not a standard reply to this question since the reading range strongly depends on a large number of factors such as the tag, the antenna with its cable, the tagged material and, last but not least, the testing environment. Read range for our full power readers (A941 and R4300P) combined with antennas, cables and a good performing tag can be up to 10 m. This value can significantly drop down in an hostile environment or grow up in a favorable condition.
  • Q. What is RSSI and how can be measured using CAEN RFID readers ?
    A. With the term RSSI (Received Signal Strength Indicator) we refer to the power of the signal backscattered by a tag and measured by the reader at its antenna ports. In CAEN RFID readers, RSSI measurement is disabled by default, if you want to enable it, you have to turn on the RSSI field in the flag parameter of the InventoryTag method (additional information can be found in the CAEN RFID API reference manual). The value returned by the reader is expressed in tenth of dBm; for example, a value of -453 means that the power level of the signal backscattered by the tag is -45.3 dBm.
    The table below reports, for each CAEN RFID reader, if the RSSI measurement is supported and, when supported, the firmware version at which the RSSI feature has been introduced.
    Reader RSSI feature Unit Note
    A528 Yes tenth of dBm starting from firmware release 3.0.0 *
    R1230CB Yes tenth of dBm starting from firmware release 1.5.0
    R1260I Yes tenth of dBm starting from firmware release 1.5.0
    R1240I Yes tenth of dBm starting from firmware release 1.0.0
    R4300P Yes tenth of dBm starting from firmware release 1.0.0
    A941MEI No N/A N/A
    A941MEO No N/A N/A

    * A528 Firmware releases older than 3.0.0 return an RSSI value whose unit of measurement is different from tenth of dBm. For these firmware releases the relation between the RSSI value returned by the reader and the power of the backsacttered signal in dBm (PdBm) is : PdBm = (0.8 * RSSI) - 120,4
  • Q. What is the output power available at the reader connector ?
    A. Please refer to the following table to know the output power available at your reader's connector:
    A941EU : 60 mW - 1.5 W programmable in 256 steps (for both IP65 and OEM version)
    A528 : 10 mW - 500mW programmable in 8 steps
    R1230CB : 8 mW - 200 mW programmable in 15 steps
    R4300P : 50 mW - 1.5 W (EU) or 1 W (FCC) programmable
    R1260I : 16 mW ERP - 400 mW ERP programmable in 15 steps
  • Q. How can I read the A927Z and RT0005 Temperature Logger UHF tag ?
    A. Both A927Z and RT0005 Temperature Logger tags have a dedicated demo application that can be downloaded from our website (see under the Software product tab). The applications permit to configure, control and download data from the tags.
  • Q. Using the readers with 4 antennas, is there the possibility to check which antenna has detected the tag ?
    A. You can identify via software which antenna has detected the tag either using the log file generated by our demo application or developing your own application using the API we provide (please refer to the API manuals for further details).
  • Q. Is there a way to put a password in order to read the EPC C1G2 data ?
    A. The EPC code in Gen2 tags is in a read/write memory bank. There is the way to lock it, both temporarily or permanently, but unfortunately the Gen2 protocol does not provide a way to protect EPC code from reading. It can be protected only for writing as well as the User memory bank. You can only protect from unwanted reading the Kill and the Access password fields. For further details on the protect/locking features of Gen2 protocol please take a look in the Gen2 protocol specification (starting from chapter 6) available at
    All the features explained in the protocol specification about protect/locking are implemented on our readers using Read, Write and Lock functions.
  • Q. How can I connect the Slate reader (Mod. R1260I) to the CAEN RFID applications ?
    A. You just have to select the RS232 option on the application and enter the COM port number (i.e. type "COMx" where x is the port number where your driver has mapped the virtual port). The Slate reader has an internal USB to RS232 converter so follow the instructions on FAQ #4 to know how to obtain the COM port number.
  • Q. Is it possible to lock the information inside a EPC Gen2 tag's memory ?
    A. You can use the Gen2 Lock function/method of our API that requires a parameter called payload. The meaning of the bit in the payload parameter required by the lock command is as follow:

    Each bit set to 1 in the MASK field allows you to write the bit of the corresponding ACTION FIELD (for example if you set to 1 the bit 19 of the KILL MASK you will be able to write to 0 or 1 the bit 9 of the KILL ACTION field); each bit set to 0 in the MASK field masks the write operation in the corresponding ACTION FIELD. The two bits of the EPC, TID and USER ACTION field mean the following:

    For example, if you are using a payload value of 0x0C030, this should permanently prevent of writing the EPC code. In the case of tags that implement the USER memory, the value 0x00C02 will make the USER memory writeable only from the secured state but not from the open state.
    Another example: the payload value 0xC0200 makes the KILL memory word not readable nor writeable from the open state, while you can read or write it from the SECURE state.
    A tag that has the ACCESS word memory set to 0x00000000 (default condition) is always in the secured state and cannot be killed. For further details on the protect/locking features of Gen2 protocol please take a look in the Gen2 protocol specification (starting from chapter 6) available at

  • Software/Firmware
  • Q. How to connect my reader to a Java application using the serial port ?
    A. Unfortunately Java language does not provide a native support for the serial ports so we have to use a third-part library for that purpose. We have chosen the RXTX library that seems to be the most adopted. You can download the RS232 Java support at: and follow the installation instructions on the RXTX website in order to correctly install the library. By the way, the archive contains the drivers for many platforms. For Windows O.S. the important files are:
      • Windows/i368-mingw32/rxtxParallel.dll
      • Windows/i368-mingw32/rxtxSerial.dll
      • RXTXcomm.jar
    to install the RS232 support you have to copy:
      • rxtxParallel.dll and rxtxSerial.dll under the folder \jre\bin
      • RXTXcomm.jar under the folder \jre\lib\ext and \jre\lib
    If you have to develop your own application using for example Netbeans, you have to copy this files also under the jre folder inside your Java jdk folder. If you forget to copy it, you can run your application without problem but you cannot debug it (it doesn't find the serial communication if you run it inside Netbeans).
  • Q. How is the output power expressed in your API functions and methods ?
    A. Power settings in API functions and methods are expressed in mW conducted power at the reader connector. In order to set the conducted power that generates the desired effective radiate power you shall apply the formula explained in the relevant FAQ.
  • Q. Is it possible to configure the reader in order to read tag's IDs autonomously ?
    A. Most of Easy2Read readers have this feature (called "continuous inventory") that is available through the API method InventoryTag (please refer to the API documentation for further details).
  • Q. Where can I find the last Firmware/Software version for my reader?
    A. You can download the last firmware/software version for your reader on our download area clicking on the respective link.
  • Q. How does the communication with the host computer work? Does the reader give to the computer the different IDs he received ?
    A. Together with our readers we provide libraries for the most used programming languages (C, .NET and Java). For example, in order to read the IDs seen by the reader at a given time, you only need to call a method (or a function) that returns an array of IDs. The libraries hide the details of the host-to-reader binary protocol. Please look at the API documentation for further details.
  • Q. Where can I download the protocol specifications and the CAEN RFID API manual ?
    A. The protocol specification and the CAENRFID API manuals are available for download at our website in the documentation page.
  • Hardware
  • Q. How can I use the digital General Purpose I/Os in your R4300P reader ? What is the meaning of the GP I/O pins ?
    A. The ION R4300P reader has 13 GP I/O bi-directional pins to be used to control external device or to send to the reader trigger signals. Their default direction after a power on reset or a general reset is set to Input.
    The I/Os functionality can be tested using the Easy Controller demo application.
    When you use the APIs to control the GPIOs from your own application you need to specify a bit mask as a parameter for the SetIO() method/function: GPIO0 correspond to bit 0, GPIO1 to bit 1 and so on.
    Using the same bit mapping you can configure each GPIO line as Input or Output with the SetIODirection() method/function.
    Please refer to the R4300P user manual for further details about pinout and electrical characteristics and to the API manuals for further details about the I/O software control.
  • Q. I'm using an RS232/USB converter, how can I connect the reader to the CAEN RFID applications ?
    A. The USB-RS232 converter creates a virtual serial port so you can think to the USB port as a standard COM port. To talk with the reader you must select the RS232 choice on our CAEN RFID demo application and enter the COM port number (i.e. type "COMx" where x is the port number where your driver has mapped the virtual port). To know the COM port number where your driver has mapped the virtual port follow these steps:
      1. Click Start -> Control Panel/System
      2. When the System Properties window appears, click the Hardware tab
      3. In the Hardware tab, click Device Manager
      4. In the Device Manager, double click the COM PORT
      5. See which ports are available. Usually COM1 is used for the true serial port. The other port should be the virtual port.
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