New to RFID?

RFID is a useful tool to identify and track individuals within a large population to monitor movement, track behavior or keep inventory. Inexpensive tags with a unique identifying number can be read at a short distance that depends on the tag size and antenna design. Passive RFID tags are inductively charged by the reader and so do not have a battery. Tags can remain operational for decades.
					An antenna can be constructed at a point of passage (stream, trail, culvert, underpass, etc) and a reader will record the time and identifier of each tag detected. RFID can be used for monitoring fish behavior, wildlife migration, monitoring animal herds and tracking rocks, among other things.
	Magnetic Communication Low Frequency RFID uses magnetic fields to charge the tag and read back the number. This kind of signal can travel through most non-metallic materials, including water, wood, plastic, glass, concrete, mud and dirt. Since HF and UHF signals cannot travel through water, LF RFID is the choice for fish and wildlife tracking. Though the read range can be degraded when metal is nearby, it can often give acceptable performance. There are techniques that can be used to minimize the effect. Contact Oregon RFID tech support if you need to place antennas near metal.
Half Duplex (HDX) A half duplex RFID reader generates short magnetic pulses at the antenna. These pulses are picked up by the tag and charge a capacitor that is a short-term battery to power the tag when the charge goes off. The tag uses the stored power to respond with the numeric identifier. Since the charge field is pulsed, HDX readers requires less power than FDX. The read range is better than FDX because the charge is off during the listen cycle.
Full Duplex (FDX) Full duplex RFID generates a continuous magnetic field which powers the tag to repond. This directly charges the tag to respond immediately. Since there is no charge time, FDX tags can scan up to 30 scans per second versus 14 for HDX.