125 kHz (LF) readers

Low Frequency RFID Readers are electronic circuits that receive energy in the band of 100 kHz to 140 kHz. There are a large variety of LF readers that vary in power levels, complexity and cost. The proper reader is selected by taking into account which transponder tags are to be read, the range performance required, whether both read and write capability is required, the security level desired and power source available for energizing the circuits.
LF readers are available as completely integrated units or may be obtained in modules. Separate modules may give the designer flexibility in choosing the communication interface, RS232 or RS422, using single or multiple antenna multiplexing, having manual or auto-tuning adjustments and a long list of specialized programming features. Some LF portable readers are available as hand-held data terminals, PDA's, and peripheral interface devices.

13,56 MHz (HF) readers

High Frequency RFID Readers are designed to read and write information to High Frequency “Smart Labels”, typically operating at 13.56 MHz. These Readers come in all shapes and sizes and prices. The primary differences between these Readers is the following features:

1.) Power output. Typically the higher the output power the better the range performance.
2.) Intelligence level relative to anti-collision techniques. Some Readers have complex multi-tag handling algorithms able to separate hundreds of tags per second. Cheaper, smaller, simpler Readers depend on their host computer to handle the intelligent functions.
3.) Readers support varying levels of input/output functions. More sophisticated Readers typically offer relay contact outputs that can drive external control circuits.