RACE RESULT Active transponders use 2.4GHz to transmit their passing data to the Active system. 

2.4GHz Transmission

When data is transmitted from a transponder to the Active System it also expects an acknowledgement from the system, if this acknowledgement is not received then it will continue to retry sending the data.The rate of retry varies with different transponder types, but all follow the pattern of several faster initial retries then with exponentially slower retries until the maximum retry count is hit. If this still fails then the passing will be automatically stored on the transponder (ActivePro / MotorKart only), the same as a passing received in Store mode. 

ActivePro V3 Performance

When an ActivePro V3 Performance is activated by a loop it will first send a pre-warn packet via 2.4Ghz, this can be used as an alert that a participant is approaching, useful when displaying data as soon as possible is important. This is not normally used or shown in RACE RESULT 12. 

The ActivePro V3 performance also has the fastest and highest rate of retries of any transponder type using the Quad Channel Backup as described below. 

Note that when battery is 2.5V or lower and temperate is -20°C or lower the output power of 2.4GHz will be reduced to avoid drawing too much power from the battery. 

ActiveBasic / ActivePro / MotorKart V3

Since most passings are successfully transmitted to the active system on the first try and with the improved 2.4GHz antenna of V3 transponders, the first attempt to transmit data is done so at a reduced 2.4GHz output power. Similar to the ActivePro V3 Performance the output power will also be reduced when the battery level is <=2.5V and temperature is <= -20°C.

If this first try does not receive a successful acknowledgement then it will be immediately followed by a retry at full power, after which the transponder will continue to retry as described above. 

This logic provides significant battery saving over V2 transponders, however it may result in a lower average 2.4GHz RSSI since passings received on the first try were transmitted at a lower power.

If the first try fails then this does not count towards any warnings (NoAck) in the passing data. 

Note that the retry logic for ActiveBasic V3 is slower than both the ActivePro and MotorKart. 

ActivePro / MotorKart V2

The V2 range of ActivePro and MotorKart also send the pre-warn packet (as described in the ActivePro V3 Performance). 

These have a slower rate of retry than V3 transponders and without the reduced power first try. 

ActiveBasic V2

The ActiveBasic V2 has the slowest rate of retry with no pre-warnings. 

 

2.4GHz Backup Channels

Each 2.4Ghz channel contains both a primary and backup frequency which helps improve 2.4GHz communication, particularly in environments with high noise / interference. Check Active System 2.4GHz Frequencies to understand the individual frequencies used.

ActivePro V3 Performance - Quad Channel Backup

As the performance version of the ActivePro V3 is aimed at providing the fastest and most reliable possible data transmission this includes a Quad Channel backup for 2.4GHz communication. 

With this there are 4 pairs of channels 1/2, 3/4, 5/6 and 7/8, on which the transponder will attempt to transmit data on both the primary and backup frequemcy for each channel in the pair.

To make use of this a second system can be setup on the alternate channel of the pair, this can be with or without a loop. If connecting a loop to the second channel backup then there should be a sufficient gap between the two loops to prevent interference. 

e.g. a primary finish is setup with the loop set to CH1, a second system is setup 5m after the primary on CH2 with no loop connected. Loop ID in this case is not important. 

The passing data received will contain the Channel and Loop ID of the loop on which the transponder was activated - in this case the device ID should not be used as a unique identifier. 

V3 / V2

All V2 and V3 transponders use a dual channel backup for 2.4GHz communication, with this the frequency will switch between the primary and backup frequencies of the channel. 

When using a decoder with and Active Extension the V1 Legacy Mode of the system must be set to AUTO or OFF. 

V1

With V1 transponders the 2.4GHz transmission is only on a single frequency. When using V1 transponders either alone or as part of a mixed population (V1/V2/V3) with a decoder and Active Extension then the V1 Legacy mode must be set to AUTO or ON. When the system detects a V1 transponder then the auto-channel switching will be disabled until the system is rebooted. 

Active devices with FW version 2.6+ do not support legacy mode and should not be used with V1 transponders.