The easiest way to provide a backup against the timing device dying (e.g. battery runs out) is as follows:
Use Master / Helper timing mode
Set Helper as receiving data vie Bluetooth
Set Master not accepting data from Helper
If Master with chip timing dies, you can switch to timing the race manually on the Helper device which will have a copy of all timing data as of the time of the Master dying so you can continue timing without missing a beat. The Helper can then be promoted to post the (official) results - you can also turn on live results on the Helper in the middle of the race.
The best backup is to run a complete duplicate system:
Duplicate RFID reader with its own antennas separated by 10-15 feet to avoid interference
Separate power source for each (not a shared generator)
No shared router between the two devices
To guard against a software bug (operating system or Webscorer):
- Use a different operating system on each timing device
- For example, if primary runs on Windows, use a iPad, Mac or Android for backup
Video backup is always recommended, a useful backup for the cases where the timing setup was not done correctly, chips are not getting detected etc.