Tool
UHF reader
The only thing that can see EPC tags — from a USB stick on your desk to a handheld that counts a shop in an hour.
UHF RFID needs its own kind of reader: a 900 MHz transmitter, a sensitive receiver and an antenna, all speaking EPC Gen2. Phones, Flippers and Proxmarks can't do it.
#Three kinds
- Desktop USB readers: cheap and low-power, with ranges of centimetres to a metre. Fine for reading and encoding a few tags on a desk.
- Handhelds: a pistol-grip reader, often clipped to a phone. These are what shop staff carry to count stock, and they read metres away.
- Fixed readers: a box with several external antennas, built into doorways, conveyor belts and ceilings. Up to about 10 m.
#Settings that matter
- Region. The reader must use your region's band and power limit (902–928 MHz in the US, 865–868 MHz in Europe). Using the wrong one isn't just a bad idea, it's not legal.
- Power. Turn it down to read only the tag in front of you. More power reads more tags, including the ones you didn't want.
- Session. S0 re-reads tags constantly; S2/S3 count each tag once per sweep. See UHF — 860–960 MHz for why.
- Antenna. Circularly polarised antennas read tags at any angle; linear ones reach further but care about orientation.
#Try it
Read a tag on something you own, then read its TID to see who made the chip. Paste the EPC into the decoder on clothing and inventory tags to see what it says.