Explain the key drivers of an RFID system. The RFID system and its performance can be attributed to tags, readers, antennas, and the software controlling the devices which is called middleware. Each of the core components has the capability to totally disrupt the performance of an RFID system.
Describe the function of firmware. Firmware is the specialized device software that controls what happens inside the readers and with the antennas. Depending on the reader, the firmware can have some filter functionality that limits the amount of traffic required to go over the network.
Describe a basic troubleshooting protocol. A basic troubleshooting protocol identifies all the variables that have the potential to impact the performance and stability of a system. The variables should be identified down to the lowest possible level. After the variables are identified, they should be tested one at a time to determine whether any one specific variable is the root cause of the problem.
Illustrate business processes having an impact on read rates. The way that you do things when RFID readers are around can be as important as how the readers are set up. Business processes determine how things are done. These processes need to be considered when setting up an interrogation zone so you can make sure that a person, vehicle, or material-handling machine does not interfere with the RFID reader's ability to send a signal to the tag and receive a signal back. Standing in front of the antennas that are attached to a reader can create an impenetrable barrier to reads, so know where workers can and can't be is a key part of mapping the business processes.
Determine how cabling affects an interrogation zone. Cabling comes in varying levels of insulation to protect from signal loss and noise. The industry standard is LMR-240. This size is effective for distances under 25 feet from the antenna to the reader. The more connectors that are attached to any cable, the more loss that is likely to occur as the signal travels from the reader to the antenna.
Verify that a reader is communicating data to the outside world. Connecting an interrogator to a laptop and then pinging the reader to make sure it is communicating to the outside world is essential to troubleshooting a communications problem. Most readers are deployed with a fixed IP address (not DHCP), which are IP addresses from a specific subnet (normally starting with 10. or 168.). You need to know the IP address before you can ping it.
Define a standing wave. A standing wave from tag to interrogation antenna is a wave in which the distribution of field strength (always a null) is formed by the superposition of two waves propagating in opposite directions. Because it is a null, there is no power to read the tag. This is also called a multi-path effect.