Transponder system

The transponder system is used in the timing and scoring systems of cycling, speed skating, short track, and cross-country skiing. The transponder is attached either to the athlete’s ankle or to the bicycle fork (for cycling). When the athlete crosses a timing point — start, finish, or intermediate — the system records the time and identifies each participant.

The transponder system consists of three main components:

• Transponders – electronic radio sensors housed in a plastic casing with a built-in battery.
• Antenna loop – when crossing the antenna loop, the transponder transmits its unique code. This signal is received by the transponder decoder and passed to the specialized timing and scoring software. The loop consists of thin copper wire and can be fixed on the surface of the track, embedded beneath it, or frozen into ice or snow.
• Decoder – a controller that manages communication between each transponder and the result processing software. The decoder features built-in flash memory capable of storing up to 65,000 reads, and is equipped with an Ethernet interface for data transmission over a local network.

Technical specifications of the transponder:

• Dimensions: 30 mm x 47 mm x 13 mm
• Weight: 16–17 g
• Housing: Impact-resistant and waterproof
• Maximum speed: 75 km/h
• Detection time: 0.004 s
• Operating temperature: -20 to +50 °C
• Battery life: approx. 120,000 passes or 5 years