This page is a tool for answering some of the most frequently asked questions (FAQs) about WJ's RFID products. As such this page will evolve and the database of questions
and answers will grow over time.
Sales/Distribution
Where Can I Buy MPR RFID Cards? Are the WJ RFID MPR Readers compatible with the ISO 18000-6 Standard?
What EPC Standards and EPC passive tag suppliers are the MPR WJ Readers compatible?
Do the WJ RFID MPR Readers comply with Asian and European Standards?
What Operating Systems are the WJ Readers compatible?
What PDAs are compatible with MPR readers?
How can I use the WJ Reader in a mixed RFID Standards environment?
Which antennas can I use with the MPR6000/7000?
My reader does not recognize Gen2 tags, I thought these readers were Gen2 capable.
MPR Compatibility
Demo Application
What interface does the demo software support?
Why can't the User Interface Demo connect to the MPR card?
Can I see the commands that I send to the reader?
How long does an inventory take? What does the 'Inv. Period' mean?
Do I have to select an antenna port for the MPR5000?
What interface does the demo software support?
Does the MPR demo application have write functionality?
Can I write my own application?
Where can I get the source code for the Windows DLL?
Technical MPR
What is the Read distance of the WJ readers?
What is the communications and control interface on the MPR products?
Can I configure the WJ Reader as a serial device?
What is the output power of the MPR readers?
Why can I see tags with the Verify command but not the inventory command?
Why can't I write to class 0+ tags (Matrics/Symbol field-writeable tags)?
Why do I lose the tag when I use the BlockWrite option in the Demo Gen 2 Access window (or when directly using the WRITE subcommand 0x21)? Why do I lose the tag when I use the Erase Tag's Memory Bank command?
Why can't I use the MPR7000 in a laptop?
Can I read from both antenna ports on the MPR6000/7000?
My MPR stopped working, how can I get it repaired or replaced?
I tried to upgrade my MPR to the latest firmware but the action failed, can I still upgrade my card?
General RFID
What RFID Products Does WJ Make?
WJ designs and manufactures a line of multi-protocol, UHF RFID Cards that operate in the 902-928MHz ISM bands. The ultra-compact Multi-Protocol RFID PC Card (MPR) family utilizes a PCMCIA Type II form factor. They adhere to the PC Card Standard 8.0 Release. The initial MPR products include the MPR 5000 and MPR 6000 models that currently operate with EPC Class 0, EPC Class 1 and the 0+ tag protocols and have upgradeable flash memory provisions to accommodate EPC UHF Gen 2, ISO 18000-6 or other standards in the future.
WJ has also done various OEM modules. OEM products are typical designed for strategic partners and to the partners' unique requirements. To date WJ has designed and developed products for U.S., Japan and EU markets operating from 850 MHz to beyond 2.4 GHz. Products can be WJ branded and/or sold exclusively by our partners depending on the business arrangements.
WJ does not manufacture or sell passive RFID transponders (tags). WJ has designed semi-passive (battery-assisted) transponders for UHF standards.
What Other RFID Products Does WJ Offer?
WJ offers over 30 different semiconductor products -amplifiers, FETs and mixers - and customer specific OEM RFID solutions.
Is There a Complete RFID Chip Set Available?
WJ is currently developing an integrated RFID chipset and power amplifier for the UHF ISM band. The chip performs the transmit, receive, and amplification functions of the readers.
Does WJ Offer 13.56MHz, 433MHz or 2.4GHz Products?
WJ's semiconductor products are inherently broadband and can be used over this whole range of RFID frequencies. See WJ's product selection guide and semiconductor product flyer. WJ is considering future RFID products or that may contain some of these technologies.
Does WJ make a compact flash or SD card reader?
Not yet. The PCMCIA form factor is tightly packed with components and any further reduction in size would not allow for all necessary components. We are investigating a smaller form factor, however, it will most likely not be a current industry standard size.
Do I need certification to use the MPR products in the U.S. and Canada?
The MPR Series RFID Cards have been tested and granted approval by the FCC and the IC for their frequency bands of operation. This means that as long as the unit is used in the specific manner listed in WJ's operations manual it does not need any further FCC or IC certification. However, each customer needs to understand the complete terms of this certification since there may be labeling implications. For example, if the MPR is embedded in an end product then the end product's label may need to include the MPR's FCC ID.
MPR General Questions (MPR5000/6000/7000)
What Does "MPR" Mean?
MPR is an acronym for Multi-Protocol RFID. Specifically this is a family of multi-protocol PCMCIA Type II UHF RFID products. These units read and program EPC Class 0/0+, EPC Class 1 and EPC Class 1 Gen 2 passive RFID tags in the UHF ISM band.
What are the MPR Products?
WJ designs and makes multi-protocol, UHF RFID PC Cards that operate in the 902-928 MHz ISM band: the MPR5000, MPR6000 and MPR7000. These products utilize the PCMCIA Type II package and 68-pin parallel communications interface commonly found in laptop, handheld and other computing platforms. These units utilize flash memory to enable upgrade ability for additional features or capabilities to other protocols.
What is the difference between the MPR5000, MPR6000 and MPR7000 PC Card products?
The MPR5000 and the MPR6000 utilize the same RFID reader engine. The MPR5000 is a 1/2 watt reader that has an integrated antenna for mobile applications. The MPR6000 is the same reader without an integrated antenna; it has two antenna ports with MMCX jacks for applications that require external antennas. The MPR7000 is a 1 watt reader that has two MMCX connectors and can only be used in serial communications mode.
What Protocols Do the MPR Products Support?
The MPR Series RFID Cards currently support EPC Class 0/0+, EPC Class 1 and EPC Gen 2. ISO 18000-6B and others can be added at a later date. User downloadable utility programs allow upgrades for new capabilities and features.
Can MPR cards be used as Stationary Readers?
The MPR Series RFID Cards are optimized for small size and mobility. They are devices that are used as one part of a stationary or handheld reader solution. They have the hardware and firmware capability of a complete reader but they need applications software and possibly other items. WJ MPR series devices must be used in conjunction with a host computer to provide reader functionality. A stationary reader can be constructed using a desktop or laptop computer and an MPR6000 with external antennas. The MPR readers are optimized for small size, mobility and convenience. A stationary configuration using an MPR-series reader is well-suited for feasibility testing and simple requirements, but may not be appropriate for such applications as a high-speed conveyorized reader.
Can MPR cards be used as Handheld Readers?
WJ MPR-series devices may be readily integrated with PDAs or handheld computers to provide a complete handheld RFID reader function. The MPR5000 with integral antenna is particularly suited for this type of application.
Do the MPR Products Have I/O Pins?
The MPR Series RFID Cards currently use PCMCIA and RS-232 for the main I/O and do not have separate I/O pins. However, the MPR cards can be used with conventional RS232 cabled interfaces. Please refer to the application note “MIB1000 interface board”.
Will the MPR WJ RFID Readers meet the EPC UHF Gen 2 Standard?
The WJ MPR Series PC Card products currently meet the Gen2 standard and are firmware upgradeable . The firmware application update is available for download.
Sales/Distribution
Where Can I Buy MPR RFID Cards?
The MPR line of products can be purchased through one of our distribution partners. You can purchase units directly from WJ Online Store (https://www.wj.com/onlinestore/default.aspx) or BlueStar (www.bluestarinc.com) or over the phone.
You can also buy developers kits that include MPR RFID Cards, installation software and various assorted RFID tags.
MPR Compatibility
Are the WJ RFID MPR Readers compatible with the ISO 18000-6 Standard?
The MPR Series PC Card products are presently not compatible with ISO 18000-6B, however, the ISO 18000-6C standard shares the same protocol with EPC Class 1 Generation 2.
What EPC Standards and EPC passive tag suppliers are the MPR WJ Readers compatible?
The WJ MPR Series products are compatible with EPC Class 0/0+ EPC Class 1 and EPC Gen2 Standards. The MPR Series PC Card products also offer functionality with Symbol/Matrics Class 0+ and the Impinj writable Class 0 protocols. Although not limited to this list, the MPR Series PC Card products have been tested with Alien, Symbol/Matrics, ASK, ST Micro, Impinj and RAFSEC tag products.
Do the WJ RFID MPR Readers comply with Asian and European Standards?
Asian and European frequencies are on the MPR PC Card product capability development road map for 2005. WJ Communications will announce the anticipated release dates in the future.
What Operating Systems are the WJ Readers compatible with?
The WJ MPR Series PC Card products are compatible with Microsoft® Windows® XP, Windows® 2000 and Windows® CE .NET initially. The Microsoft® Windows® Mobile for Pocket PC and possibly other operating systems will follow. Any operating system supporting serial communications is also suitable for integration with the WJ MPR Series PC Card products; functionality has been demonstrated in the Mac OS X variation of BSD Unix and should be extendible to other Unix variants and Linux.
What PDAs are compatible with MPR readers?Currently any PDA with PocketPC or WinCE and a PCMCIA card slot is compatible, however, writing software to interface with the MPR is necessary for full functionality and for versions not supported by our demo software. The WJ MPR Demo Interface is designed for WinCE 4.2 and PocketPC.
How can I use the WJ Reader in a mixed RFID Standards environment?
The WJ MPR Series PC Card products are compatible with EPC Class 0/0+, Class 1 and Gen2 air protocols. The MPR Series PC Card products are capable of simultaneously reading all of these tag types simultaneously from the same population.
What antenna can I use with the MPR6000/7000?
Any panel-type antenna whose gain does not exceed 9dBi. Please refer to the WJ MPR Series operations manual for further compliance and operation details and usage information.
My reader does not recognize Gen2 tags, I thought these readers were Gen2 capable.
The MPR cards are, however, a firmware update needs to be performed. Please download the software here. Not only does this include the C1G2 update, but also includes updated algorithms for better overall performance. For non-Gen2 applications, this firmware upgrade is still beneficial.
Demo Application
What interface does the demo software support?
The demo software supports both the PC Card Standard 8.0 interface and the serial TTL interfaces.
Why can't the User Interface Demo connect to the MPR card?
The MPR card in a laptop computer creates a UART serial interface that acts like a conventional COM port, logically identical to the serial printer or modem ports on older computers. When the card is inserted into the computer, the operating system assigns this logical port to an available port number, which could differ from one computer to another and could change on subsequent insertions if other serial devices are connected to the computer.
Please refer to our hardware installation document if you are having problems. MPR Hardware Installation Guide. If the card is shown but not recognized as a COM device, you may need to download the driver (.inf file) that allows the computer to properly configure the card.
Can I see the commands that I send to the reader?
If you are having problems reading tags or are merely interested in exactly what's going on, you can access a LOG file from the graphical user interface that shows all the commands and replies passing between the host and the reader. Go to the Options menu and select Show Reader Log.
How long does an inventory take? What does the 'Inv Period' mean?
The reader requires about 2 ms to read a single tag in the field; this time is mostly determined by the EPC standards and the data rates typical for US operation. When many tags are being inventoried, each tag is allowed a chance to respond. The Inv Period is actually a delay between inventories. If the Inv Period display is set to 0, the MPR will read as rapidly as it can. This speed is limited by the requirement to communicate with the host serial port.
Do I have to select an antenna port?
For the MPR5000, it does not matter which one is selected since the antenna port it hardwired inside the unit, however with the MPR6000 and 7000, the reader can select between the two.
What interface does the demo software support?
The demo software supports both the PC Card Standard 8.0 interface and the serial TTL interfaces.
Can I write my own application?Yes, we encourage programmers to write their own applications to fit their specific needs. The open source code is available; the API spec describes the command set.
Technical MPR
What is the Read distance of the WJ Readers?
Read distances are dependent on a number of complex conditions including the antenna configuration, tag environment and tag class and antenna type used.
Given comparable conditions, equivalent to read ranges of any other reader on the market and strongly dependent on antenna choice
MPR5000 read distance = up to 1 - 1.5 meters (3 - 5 feet)
MPR6000 read distance = up to 3 - 4 meters (10 - 12 feet)
MPR7000 read distance = up to 4 - 5 meters (12 - 15 feet)
What is the communications and control interface on the MPR products?
The MPR5000 and MPR6000 RFID Cards can be operated as either PC Card Standard 8.0 or serial TTL. These cards are self-configuring depending on the interface plugged into. The application note - “Controlling MPR Series RFID Cards in Serial Communications Mode” addresses how to interface to the MPR products in serial mode.
Can I configure the WJ Reader as a serial device?
The WJ Readers can be configured in a serial TTL mode. Please refer to the application note “Controlling MPR Series RFID Cards in Serial Communications Mode”.
What is the output power of the MPR readers?
The MPR5000 and MPR6000 have a maximum output power of 0.5 watts (27dBm). The MPR7000 has an maximum of 1 watt (30dBm). The output power can be set from 18dBm to the max in 1dB increments.
Why can I see tags with the Verify command but not the inventory command?
The MPR will only read tags with valid tag ID (EPC) values. If the tag is programmed with all-0's, or with an invalid cyclic redundancy check (CRC), it won't be read by an INVENTORY command.
Problems can also result from headers that don't match the length of the tag ID. A valid EPC uses the first byte as a header byte, which specifies the length of the tag ID. If these two bits don't match the actual length, a CRC error will result and the tag cannot be rean in an inventory. It can only be read with the VERIFY command.
The first two bits determine tag length:
00 - 96 bit
01 - 64 bit
10 - 64 bit
11 - 64 bit
It is also 64-bits if the binary AND operation of the 1st byte AND 0xF8 = = 0x08. (TagID[0] & 0xF8 == 0x08)
In other words, when writing 96 bits to a tag, ensure the first two bits of the 1st byte are both 0's, and that the
CRC is valid.
Why can't I write to class 0+ tags (Matrics writable/Symbol field-writable tags)?There are several obstacles that can be encountered in writing new data to these tags, some related to the tag design and some to the behavior of the reader signals.
To use write commands applicable to these tags, you must have MPR firmware version 2.00 or later. If you are creating your own application software to write to these tags, you should be aware of the particular memory organization and writing requirements for class 0+ tags: they are NOT the same as the approach employed for Impinj's Zuma tags, though both are backwards-compatible with the EPCGlobal class 0 standard for tag reading. The requisite commands are described in the updated version of the “MPR Application Programmer's Interface”. More information on the memory arrangement and programming guidelines for class 0+ tags is available in the applications notes “RFID Tag Memory Mapping and Programming Practice” and “RFID Tags with the MPR Series RFID PC Card”. More RFID application notes can be found at “Application Notes” section.
Writing to a tag requires more signal strength than reading. A general guideline is that if a tag can be read with the reader power adjusted to 17 dBm or less, it will be possible to reliably write to the tag with the MPR power at 27 dBm. A tag positioned so that >21 dBm reader power is needed to read it will not program.
The page to be written (typically page ID2) MUST be ERASED before attempting to write to it. Tests indicate that modest improvements in the likelihood of a successful WRITE result if as many as 10 consecutive ERASE operations are used before attempting a WRITE.
Users of the MPR5000 may find it convenient to lay tags to be programmed on a table surface adjacent to an MPR5000 in a laptop computer. This configuration can work but several precautions are in order:
- tags should be vertically oriented -- that is, perpendicular to the table surface -- for reliable write. If a single-dipole tag is being used, it must be horizontally oriented to match the antenna polarization, so in this case lift the tag 2-4 cm off the table surface using e.g. a cardboard or non-conductive plastic support.
- tables covered with anti-static mats or with a conductive top surface may cause problems with read and write range.
- conventional wooden or press board tables act to reflect the RF signal from the antenna; interference of the reflected and direct signals results in a complex behavior of power at the tag with distance, with the possibility of 'drop outs' (narrow regions in which writing is difficult), typically 20-40 cm from the reader. It is important to choose a specific location with respect to the reader antenna for the tag, and verify that the tag can be read using a reader power of 17 dBm or less (but remember to turn the power back up to write to the tag!).
In all cases in which you're working in an open environment, it is VERY important to ensure that only the tag you're working with is exposed to the reader fields. Tags that are at the fringes of the field get partially erased and appear to enter a spurious LOCK condition (described in the Addendum Manual), rendering them impossible to write to with the MPR. With an MPR5000, all tags except the tag to be written should be at least 2 meters (6 feet) away from the unit and preferably stored in an anti-static bag or metal box; tags placed "behind" the laptop are at risk, as the MPR5000 integral antenna radiates significant power "backwards" towards the laptop. If an MPR6000 is used, tags should be carefully stored outside the expected antenna beam and at least 2 meters (6 feet away) from the antenna, preferably in an anti-static bag or metal box.
Why do I lose the tag when I use the BlockWrite option in the Demo Gen 2 Access window (or when directly using the WRITE subcommand 0x21)? Why do I lose the tag when I use the Erase Tag's Memory Bank command?Gen 2 tags are not required to support the BlockWrite and BlockErase commands. If a tag does not support these commands, it simply ignores them, and does not report an error. Therefore, the reader finds a tag and issues an (unsupported) command, the tag fails to respond and the reader assumes the tag was lost. It may try several times, but of course each attempt will fail as the command is not supported.
We have so far found that the TI Gen 2 inlays (which use the Impinj chipset) and the Philips UCode EPC G2 V4 do not seem to respond to BlockWrite/BlockErase commands. At this time (1Q 2006) we do not know whether these chips will support the optional black access commands in the future.
Does the MPR demo application have write functionality?Yes, the latest version 3.0. You can download the new application that has integrated write functionality.
Why can't I use the MPR7000 in a laptop?The MPR7000 is a 1 watt RFID reader. The higher draw of current exceeds the maximum supply current of the PCMCIA slot, therefore the MPR7000 can only be used in serial communications mode and outside a laptop. Inserting the card into your laptop can cause the OS to crash.
Can I read from both antenna ports on the MPR6000/7000?Yes, however, the reading cannot take place at the same time. The reads must be done in a serial fashion as the MPR cannot transmit and receive from both antenna ports simultaneously. The reads would have to alternate from one to the other and back.
Where can I get the source code for the Windows DLL?The source code is available for download here /Support/WindowsDLL.aspx.
My MPR stopped working, how can I get it repaired or replaced?All RMA and repairs must go through our distributors, please contact your distributor for return information.
I tried to upgrade my MPR to the latest firmware. The update failed and my MPR no longer responds. Can I fix it myself?No, although it happens infrequently, the MPR will need to be returned to WJ for evaluation and reprogramming. We're sorry for the inconvenience.
My reader does no recognize Gen2 tags, is there a firmware update?Yes, the firmware update can be downloaded here. Not only does this include the C1G2 update, but also includes updated algorithms for better overall performance. For non-Gen2 applications, this firmware upgrade is still beneficial.