2nd timing mat at finish

[David Roy]

My running group only times a couple of races a year and now that we have 2 feibot mats I was wondering about the races where there are 2 sets of mats at the finish about 15 to 20 feet apart. I assume it is for redundancy, but not sure about the actual setup. Is the second and final mat at the finish line the final recorded read? Are they both on the same computer? and if so can it be setup with two 4 port readers or do I have to have an 8 port reader?

[Patrick W]

A lot to unpack here, and the answer (as with many things with timing) is "it depends" / "its complicated"... 

To begin with the thing to remember is for finish/split times the time recorded is the first read that happens at the read point, whatever reader/antenna it happens to come from.  So typically you can use a single mat + side antenna to get pretty high reliability rates with one shot to capture the chip as it passes.  To expand that for larger races / with more finish density / to protect against missing that 1 chance to read, you can add a second mat line as a backup.  This can be connected to the primary system or a secondary one (there are arguments for both), but most tie it into the main system which means that you now have 2 chances to hit that finish read, which pushes you closer to 100% (though you have to watch for close finishes, rfid is fuzzy for accuracy already, and now you're spreading your finish area another 2-3 metres).  

For readers typically 2+ readers are better than 1 for this sort of setup.  The way readers work with multiple ports is by only listening on one port at a time, and switching which one quickly...  In theory this means that they're sorta listening on all of them at the same time, and is usually alright, but in practice it can sometimes lead to an increase in missed reads if you do a primary and secondary read line on the same reader (this is why there's a variety of antenna connection patterns recommended, you're trying to make sure that the reader is covering the whole mat line), so it tends to be best to use a reader only on one line...  You can of course use more than one reader per line as well, but you have to make sure you take this into account with your setup as it can be highly dependent on which readers and mats you use as to what combination works best,...

Some setups add a 3rd read line for the announcer, though now that I live stream results if I do a 3rd line I use it as a dedicated backup system and have the announcer announces from my live results.. 

[Brian Agee]

Great job explaining the considerations with using multiple mats. Much appreciated!