RaceOS live event experience

Timing Points & Readers

Every finish time and split starts at a timing point. An antenna mat across the course detects the battery-free transponder inside each timed bib and sends the observation into the RaceOS timing journey.

What it is

The primary timing-data path — every bib crossing starts here

A standards-based UHF reader (including supported Impinj readers) connects to one or more antenna mats laid flat across the timing line. Every bib that crosses is read by its embedded transponder, timestamped, and sent to an edge computer for onward delivery—no camera, no pressure sensor, no manual button press.

How a read reaches a result

This is the single most important wire in the whole system — every finish time and split ultimately starts here.

Reader protocol — open standard, not locked to one vendor

The edge software speaks the open LLRP protocol by default, with an optional mode for Impinj's proprietary Octane SDK where that specific hardware is deployed. Every RF parameter — transmit power, antenna selection, read mode — is configurable per deployment rather than hardcoded to one reader model.

Planning an Impinj R700 fleet

The R700 deployment guide covers anti-collision, synchronized timestamps, an eight-reader starting layout, cellular store-and-forward, the current race-mat procurement change, and the complete equipment needed at each checkpoint.

Open the R700 race-timing deployment guide

Why it matters

Lay the protected antenna mat assembly flat across the timing line per the antenna manufacturer's spec — this is the physical read zone for every crossing event. The old Times-7 RTAS is discontinued; the A5531V replacement is a bare IP53 antenna and needs a proper load-bearing, non-slip, weather-protected enclosure before runners cross it.
Connect the ground antenna element(s) to the reader with correctly terminated, low-loss 50-ohm cables. An A5531V uses SMA while the Impinj R700 exposes RP-TNC ports; do not order the old RTAS cable set by assumption. Connect R700 and edge host by Ethernet on the checkpoint LAN, with the R700 powered from a correctly sized 802.3at PoE+ source.
The edge host publishes every tag read to the race/reads MQTT topic over TLS with per-device credentials — this is a required, not optional, connection: without it there is no timing data at all.

This is the primary timing source. Sentinel Pole Wi-Fi/BLE presence, CCTV footage, and mesh SOS reports (§3.10) exist as corroboration and fallback — they do not replace a working RFID mat.

RFID checkpoints show real crossings; movement between checkpoints is interpolated unless a separately consented continuous-position signal is available.

No physical R700, antenna mat, regional RF configuration, clock chain, or dense-pack load has been validated in this repository. Treat the first hardware purchase as a measured pilot before ordering the full fleet.