Detection Setup

Reaction Time

As a chip approaches the ground antenna, the RACE RESULT System monitors the signal strength of the chip. After it passes over the antenna, the system records the time of the highest signal strength, which is expected to be directly above the antenna. The Reaction Time in the Detection menu defines for how much longer a chip will be monitored after the last signal strength peak before providing the final time.

When increasing the reaction time, the calculated finish times will be more precise but it takes longer until the system can provide this time. When using a small reaction time, the system can return the detection very quickly, but the precision will be reduced.

The default value is 850ms. If necessary, this value can be decreased for fast races (e.g. mountain bike) and increased for slow races (e.g. children). For optimum precision, the reaction time value should match the average time the chip will be in range of the antennas.

Note that the reaction time setting in the decoder only applies to the passive system. For the active system, the calculation of the time happens at transponder level.

Dead Time

The Dead Time in the Detection menu defines the minimum time between two reads of the same chip.

In the passive legacy mode Detection every dt ms and when using the active system, the decoder simply ignores further reads of the same chip for the duration of the dead time, after a first read has been stored.

In the First detection only, Last detection only, First + last detection modes that were introduced in more recent versions of the firmware, the decoder checks if the chip is still in range for the duration of the dead time after a first read has been stored.

The default value of the dead time is 5000ms. It can be set to value between 0 and 9999ms.

 

Detection Mode

The RACE RESULT System supports four different passive detection modes:

  • First+last detection (default): the decoder stores a first detection based on the value of the reaction time. If the chip stays in the field after this first detection, the decoder will wait for the chip to leave the field for a duration higher than the dead time, and additionally report the last detection before the chip exited the field.
  • First detection only: the decoder stores a first detection based on the value of the reaction time. It only stores a new detection for the same chip after the chip has been out of the detection field for a duration higher than the dead time.
  • Last detection only: when the chip enters the detection field, the decoder looks for it for the duration of the dead time. When it does not see the chip for a duration higher than the dead time, it stores the last detection before the chip exited the detection field.
  • Detection every dt ms: the decoder stores a first read based on the value of the reaction time, then it simply ignores any further reads of the same chip for the duration of the dead time.

First+last detection mode is the default, as it is the one that gives you the most complete information in any situation (a start, a split, or a finish) and lets you pick the right read at software level. First detection only and Last detection only are designed for special cases and should be used with extreme care, e.g. only use the former for a finish or a split timing location, and the latter in a start scenario.

Initially, only the legacy mode Detection every dt ms was available. We recommend not to use it anymore, especially in a start scenario. If a participant stands on the line for a long time before the start, you will typically receive a lot of detections (one every 5 seconds), where you only need the last one. Using this mode, the last detection is unprecise, and if the runner is detected right before the gun fires and leaves the detection field before the dead time is elapsed, you will not have a valid start detection after T0. The new modes came about precisely to address these issues.

Beep / Blink

The On Detection setting in the Detection menu defines whether the decoder should beep and / or blink to signal a detection.

Note that there is limit to the frequency of the beeps and blinks, these are only queued for 2 seconds. If too many athletes are being detected at the same time, the system will not be able to beep and blink for every athlete, and you would not be able to make out every separate signal anyway.

If the density of athletes crossing the timing system is low, the system will signal every detectoin separately with a short delay so that you can verify the number of detections easily.