Implementing QC Processes for RFID Systems

A challenge that we face in the nascent RFID industry is lack of quality manufacturing and assembly standards from new manufacturers. Quality control (QC) is something often passed over in favor of speed or cost. Although many see this as growing pains in the industry, those pains should not be passed on to end users. If they are, the industry will be slower to adopt it and reported results will be skewed because of poor equipment.

As an implementer of RFID technology, you hold responsibility to make sure that you perform every deployment to the best of your ability, particularly if you are carrying a CompTIA RFID+ certification with you. There are two simple but very effective processes that you can execute to make sure that the overall quality of the deployment is top notch:

  • Create a Complete Bill of Materials The project management document-whether it's in Excel, Project, or EasyReader-should have a dedicated section to track the BOM. Each standard piece of equipment and application (dock door, conveyor, printer stations) should have a dedicated list of materials such as Programmable Logic Controller (PLC) which controls devices attached by the reader like light stacks and directional gates, connectors, cables, and other ancillary products. Making sure that all of these items are associated with the reader's IP address is the easiest way to keep from losing the associated items. Figure 7.1 shows Easy-Reader's primary BOM tracking screen. Note that the reader and antennas are all associated with one primary IP address. Those actual pieces of hardware will also have that IP address affixed to the outside for easy verification.

  • Test Readers for Compliance and Performance Testing the readers is the key first step to making sure you don't waste time, money, or effort in the on-site deployment. Remember, the more work you can do in a controlled, clean, quiet lab environment, the better. The following process has been proven over hundreds of reader deployments all across the globe. If you can use this type of process to get ready for the actual on-site deployment, you will be well prepared to succeed.

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Figure 7.1: BOM tracking via IP address in EasyReader

The first step toward configuring an RFID system is to set up a software tool (such as ODIN's EasyReader or even a hand-built Excel spreadsheet) to track the configuration of each RFID portal. If you don't know where each component is and where is has to go, you'll find out when you arrive on-site that pieces are missing or components are faulty.

As you prepare to test and configure the reader for predeployment, it is most helpful to set up a repeatable, measurable methodology to help the deployment scale. What we have found most effective is to set up an assembly-line-like process using long tables so that tests and configurations are set up right next to each other, as shown in Figure 7.2.

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Figure 7.2: The testing and certification setup for RFID readers

There are five key steps to pre-kitting of the readers. They are:

  1. Assign all subcomponents-light stack, antennas, uninterruptible power supply, and so forth-to each portal. This means having numbers and an identification system for your portal or associating each peripheral and required component to a specific reader. That way, when everything gets tested, it can be put together.

  2. Record serial numbers for reader, printer, and PLC into a spreadsheet or EasyReader so that each serial number is mapped to a physical location on the site. Each location should have a specific reader and system setup.

  3. Assign a virtual IP address to each hardware device in the spreadsheet or EasyReader.This step makes it a lot easier for the network folks at the client site. Before you get on-site, ask the network guy for a block of virtual IP addresses that you can preload onto each reader. Just make sure that you keep track of each reader and its location to make sure that you are not confusing readers by IP address.

  4. Test each reader and associate the results with the specific device and serial number either in the spreadsheet or your software program. Testing the reader requires the following tests:

    • Record conducted power output measurements at each reader port. To do this, you need to attach either a power meter or a spectrum analyzer to each port and turn on the reader to full power. You also need to set a threshold for failure-usually a variance of 5 percent is acceptable. So for a UHF reader, we would look for an average of 1 watt in the United States. If it goes to 1.05 or down to 0.95, that is acceptable, but beyond that would cause the reader to be failed because it does not meet FCC compliance. Knowing the regional regulations is critical to understanding the testing requirements.

    • If power exceeds 1 watt of conducted power, mark the reader noncompliant with FCC specs and return the reader to the manufacturer.

    • Conduct a basic functionality check.

    • Configure the IP address on the reader based on an EasyReader or Excel spreadsheet assignment.

  5. After the reader is tested, the next step is to configure the reader based on the site survey and analysis. If you have planned correctly, you should know which reader is going to a dock door, which reader is going to a conveyor, and so forth. At this point you need to start planning for shipment and making sure that the right hardware gets to the right location. This is usually where we create an IP address label and affix it to the reader's exterior.

The associated peripherals need to be set up, tested, and associated with a location in your spreadsheet or in EasyReader. The next logical item to test out and make sure it meets the needs of the particular location is the antennas. For each antenna, you have to make sure that you have adequate cable and that you bundle with the antennas any connectors needed to attach the antennas and cable together. Keep in mind that if you have a mono-static antenna, you need only one cable, and if you have a bi-static antenna, you need two cables for every antenna going with the reader.

The light stack is a critical piece of equipment that marries the business process and the workers interfacing with the RFID system, with the technology. The challenge is that most light stacks (the red, yellow, green indicator lights to signal people about an RFID read) are not Plug and Play with an RFID reader. Therefore you need to use some sort of controlling box. This is usually a PLC box. To communicate with the box, you'll need to connect through Telnet (the protocol for remotely accessing a device over the network) into the PLC and configure the box according to your business process specifications.


When you connect through Telnet into the PLC to configure it for the light stack, make sure you issue an Activate Light command for all three colors in the light stack. To keep your items straight, create an ID tag for the light stack that associates the PLC with the light stack and the reader.

There are two other pieces of hardware that will need to be tracked and prepped prior to being shipped out the door: the printer and any handheld units that you have slated for deployment. The preconfiguration testing for both of those items is quite similar: turn them on, write or read a tag, and power them down.

By following the processes I've outlined for testing and certifying hardware, you will be ready to ship out all your equipment and organize your team on-site.

CompTIA RFID+ Study Guide Exam RF0-101, includes CD-ROM
CompTIA RFID+ Study Guide Exam RF0-101, includes CD-ROM
Year: 2006
Pages: 136 © 2008-2017.
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