As with all UHF timing systems a transponder should only be in the field of one reader at any one time, furthermore, the strong output of one reader may inhibit the receive antenna of another box when directly facing each other. 

To avoid interference between devices, Track Boxes are able to synchronize using the on-board 2.4Ghz which prevents the collision of the UHF readers. There are 2 modes of synchronization - pairing (2 boxes) and multi (more than 2 boxes).

Two or more boxes will automatically synchronize their UHF Readers to optimize read performance when:

• The boxes are within close range to each other (approx. 20m)
• The same 2.4GHz channel is set
• The reader is turned on (not in standby or laying flat)
• The reader is in NORMAL or FAST mode (not SLOW)

When synchronization is active the green LED (to indicate GPS & Network OK) will switch to a quick double blink.

Dual box synchronization is always enabled automatically regardless of the orientation of antennas, as even 2 boxes with their back to each other may experience some interference. 

Synchronization is automatically disabled if the above criteria are no longer met, for example if the boxes are moved apart or the channels of the boxes are changed. It is also possible to disable dual box synchronization using Custom Track Box Configuration Rules.

As Track Box synchronization and Active Track Ping Detection both rely on the 2.4GHz antenna it is not advised to use the Track Box synchronization whilst also expecting Active Track Pings, since this will reduce possibility for the Track Boxes to receive Active Track Pings. Additionally, Track Boxes can only operate on a single channel, so changing the channel for pairing devices will change the channel on which the device is expecting to receive Track Pings. 

Track Box Pairing

Using two Track Boxes together allows to cover a greater width of timing point and also maximises the chance for a clear line of sight between the antennas and transponders. When in pairing mode the Track Boxes will report SYNC in the RACE RESULT 14 Timing tab.

When in pairing mode the read rate of each box will be reduced by just over half to around 20x per second (down from approx 50x a second for a single unpaired box), this will result in reduced hits per box, for each transponder. When comparing a pair of boxes to single box performance you can expect roughly similar hits however the sum of the pair is still likely to be slightly lower due to having just under half the available read time per box. 

If you have multiple boxes in close range, then you can create pairs of devices by setting the channel accordingly for each device. In this case, you should take care that any 2 boxes which are not synchronized do not have overlapping fields which may cause interference.

Multi Track Box

When more than 2 Track Boxes are in close range and meet the synchronization criteria they will enter Multi mode, this is also indicated in the RACE RESULT 14 Timing tab (MULT)

In Multi mode each box will drastically reduce its read rate to a much slower random mode. This mode is intended for use with indoor applications with many boxes in close proximity and is not intended for sports timing.