Exam Essentials

Know the business processes that surround the use of RFID. Map out the various functional roles within the organization at each location. Determine what happens when an item, case, or pallet comes into a facility, goes out of a facility, or both. Document the process by using swim lanes, which allow a visual representation of the facility's work flow.

Explain the various touch points of RFID. RFID impacts the information technology (IT) staff. Network connections as well as data storage and backup are required, and another device has to be managed on the network. Large objects are being permanently installed within a manufacturing facility, store, warehouse, or distribution center, and there need to be electrical outlets to support them, protective items such as bollards and racks bolted down, and specifications included in any system changes. Finally, the RFID network will impact the workforce and how they do their tasks-the business processes. Mapping out what happens when a tag is not read (an exception process), developing strategies to provide a visual alert by using a light stack, and determining where to put the readers all should be decided based on the business processes.

Understand how to read blueprints. Blueprints are a graphical representation of an actual building. Engineering drawings are blueprints with material handling systems shown as installed-conveyors, storage racks, and so on. Understanding that every set of plans has a scale that is consistent will help you measure interrogation zone locations, plan for cable lengths and distances, and graphically represent where each interrogation zone will be installed.

Explain how to perform a full Faraday cycle analysis site survey. A spectrum analyzer is set up to look within the specific frequency range that is being deployed, before any equipment arrives at the facility. The analyzer should run continuously in the facility for 24–48 hours at different locations to determine whether there is any ambient environmental noise (AEN) that might interfere with the RFID system.

Demonstrate how to find the source of AEN. Using the spectrum analyzer on a mobile cart, move around the facility in concentric circles and note when the signal gets stronger and weaker. Triangulate the strongest signal and pinpoint the source of the AEN.

Tell why a site analysis is important when using UHF. Most RFID, including UHF, operates within the Instrument, Scientific and Medical (ISM) band. This frequency band is unlicensed and can be used by any device meeting FCC part 15 rules. Therefore, there could already be devices in place that are using the same frequency band. Before an RFID system is installed and drowns out the signal of another system, or gets installed and doesn't work, the installation team needs to understand what is happening in the facility.

Explain why you need to look at the macro and micro environments. Understanding what is happening with other RF energy is critical to the overall system, but only by performing a detailed analysis at each location can you understand how each individual reader is going to function. Using science and not trial and error is the key to installing a successful RFID system.

Know how to read a PLCM map. The path loss contour map (PLCM) shows what happens to RF in a field when using the actual antennas a reader will use. Knowing that a perfect graph will show you where RF energy is being absorbed means you can tell where null spots are and can make plans to work around them.

Explain the basics of the ISM band and UHF relating to RFID. The ISM frequency band is an unlicensed band, so any device meeting FCC specifications can be used on this band. The ISM band for UHF is between 902 and 928 MHz in the United States. FCC rule part 15 requires any devices that communicate over that frequency to hop pseudo-randomly about that range.