In this chapter, you learned about various peripherals that can be implemented with the RFID system. Some are necessary for printing labels and encoding tags, others are used to trigger interrogation or provide feedback about the result of tag function verification.
In the first section, you learned about the function of and reason for implementation of RFID printers/encoders. RFID printers are often used for slap-and-ship or exception processing. They not only print information on the labels, but also encode and verify the embedded RFID tags. You learned guidelines for printer installation and configuration and found out about printer calibration and various ways it can be performed. Also, in order to encode the tags, you have to have the right kind. I described the two main printing methods that use different kinds of media.
Next, you learned about different kinds of label applicators and the applications they are most suitable for. The wipe-on label applicator is best for same-sized products or packaging, whereas the pneumatic piston label applicator can handle different sizes of boxes because of its proximity sensor. This type of label applicator also can apply the labels without touching the item by blowing the label on.
Following printers and label applicators, you learned about triggering devices and their importance. To reduce the RF noise in the environment as well as increase the interrogation zone efficiency, you should trigger interrogation only when needed. For this purpose, you would install motion sensors or use timed, software, or manual triggering.
After triggering devices, you learned about feedback devices. You learned that light stacks and sound devices such as buzzers and horns are used to provide an alert if the tag is not functioning. Diverters can then route each item with a nonfunctioning tag to the exception processing area, where the item can be retagged. Of course, light stacks, buzzers, and diverters can be used for other types of signaling and for routing products to their appropriate locations.
You learned that the tags can stop functioning and that is why you have to place verification points throughout your system. You must verify the tag after it is applied on the product or packaging.
The last section of this chapter was dedicated to real-time location systems, their function, and their use. You learned that to locate an item (tagged with an active tag), the system uses triangulation or signal strength measurements; the usual accuracy distance is around 7 to 15 feet.