RFID SYSTEM

摘要

An antenna (A) is disposed in the vicinity of a pathway on which a moving object (pallet) (P) travels, and a fixed tag (T) is disposed at a position from which radio waves from the antenna (A) can be received. A moving tag (M), attached to the moving object (P), and the fixed tag (T), upon receiving a read command from the antenna (A), send back a response signal at a certain timing. The signal received by the antenna (A) from the fixed tag (T) is substantially constant, but while the moving tag (M) is located at a point where there is to be communication with the antenna (A), the signal from the fixed tag (T) becomes embedded in the signal transmitted from the moving tag (M) to the antenna (A) and can no longer be read. By contrast, when the moving tag (M) is separated from the antenna (A) by a certain distance or more, the signal from the moving tag (M) becomes embedded in the signal from the fixed tag (T) and can no longer be read.