Chip Time Issues

[Craig MacIntyre]

Not sure if there is any easy solution or not.

Generally for events (smaller 5km, bike fondos, etc) we just go with gun time.  We had a largish (for us) 5km and the RD was adamant about using chip time for age group and final times and gun time for overall.  In theory no problem.

However, we still struggle with high density start/finish reads.  Over 15% of starters were missed.  Which makes chip time even worse - a couple of guys started and finished together (as an example).  One had a 4 second slow time.  yes I can fix this manally but it is both a PITA and destroys our credibility.

So what to do?  My guess is it is a combination of hardware choices that are killing me.

Setup.  Bib chips, foam backed.  I cannot do anything about improper location but that wasn't an issue for many of the misses.

Impinj 420 and 700 readers.  The 420 is on a Feibot mat (for smaller events I like to use 2 side antennas and the two center antenna on the mat but here we just used the mat.)  The R700 was 3 antennas set 5m from the mat.  I had an Impinj threshold antenna and two cirecular ones.  The threshold was overhead.

I had a bit better density readings when I had a Motorola 9500 but not by much.  I have thought about using two threshold antena's overhead with a circular one between.

Here is the other problem that I don't know how to address.  If we separate the mats far enough for clean reads the read times are still more than 1 second off.  How do you deal with that?

The struggle is real!!!!!!!

[JK Race Timing Systems]

Hi Craig

Yep Agree, Race directors have bought into "Chip Starts" as critical when the absolute majority of races are better off without them, ironically races that have a very wide area of road that could get everyone over the line in seconds being coralled though a chip start mat exaggerating the time difference between gun and chip!!! As ye say in the states ...go figure

Anyway Impinj threshold...Unreal antennae  but they have as you probably know a slot antenna and operate slightly differently.

What orientation is your chip on the bib and how is the antenna sitting

best regards

JK

[Raphael Leal]

All of the races that I time the RD requires 3 or 5 Overall winners by gun time and age group by chip time.

My current set is 1 FX7400 with 4 side linear antennas as the main system and 1 R420 with 4 mat antennas separated at least 2,5 meters from the main antennas.
Bib tags with foam on the back, model ZEPHYR from Checkpoint (M750).

My read rate including the high density start (+1000) is less than 2%.

[Raphael Leal]

*my miss read rate is less than 2%.

[Bill Stokes - Stokes Race Timing]

Craig, I have found that slowing the runners down from crowding the start line is a good solution as well as narrowing the starting shute to minimize the density. Because it is a chip start the runner's time doesn't start until their chip is read the last time as they pass through your antenna array.  So no one needs to start running until they get through the starting shute (or crowd the start line).  Race directors need to be educated that doing a "gun" start to start their chip start event only applies to cross country races and really isn't needed in a chip start event. 

I timed a 450 person fun run 3K / 5k on June 22nd and captured all the chips at the start by simply asking the race director to corral the line up so that only the first 100 or so runners "ran" through the start line when they said "Ready, set, GO".  We had 2 people hold back the rest of the field using a long rope.  As soon as the first 100 or so got through the starting shute, they dropped the rope and the rest moved forward.  Most were walking so it made capturing their bibs easy.  Slowing down the runners also helps your Laptop keep up with the tag reading.  Here's a video I made of the start of the race so you can see my setup and how I did it: https://www.youtube.com/watch?v=7sxH3ZfTALQ

You can't see the 15 ft wide inflatable arch I was using because the camera was on the finish line side of the arch.

I used one Motorola 9500 with 3 antennas on one side and 4 on the side I'm on.  I have used two 9500's before but didn't get any better results.  I don't use a mat antenna (never have).  I adjust the antenna heights of the antennas to 3 levels (high, mediuim and low) and angle them slightly towards the runners.  I put one DogBone Tag vertically in the center of the bibs without any foam insulation.  I only use foam on the longer runs where the runner might sweat so much so as to short out the tag read.  Sometimes I turn one of the antennas to point at the backs of runners at the start of the race.  I do this when the race director does a poor job of directing runners to pin their bib on the front.

Hope this helps to give you some ideas on how to do chip timing start without worrying about missing chips. 

I've been timing races since 2013 using ART.

-Bill

[Craig MacIntyre]

Thanks all.  What I am seeing I think is bad luck?  Since switching to mat antenna finishes with a single mat and some other antenna I have just not had good read rates.  Perhaps it is the Feibot mats.  I understand that bib chips combined with mats is not the best solution but a lot of RD's want that exact answer.  More testing ...

[Patrick W]

We would need to know your full setup better, chip orientation, readers, spacing, the works.  Mat antennas should be no issue for getting chip starts.

[Craig MacIntyre]

Sure

Vertical chips (R6P core - from Feibot) - the mat was ordered with vertical orientation - this impacts my threshold antenas as they are obviously more sensitive and so I have to make sure I have good read angles

Foam backed

Impinj r420 on the mat

Impinj r700 or r220 on the side/overhead)

Spaced between 2-5 meters between the mat and the others - trying to avoid interference (in theory the Impinj are supposed to work together to avoid this but using a meter I still got gaps so I moved them)

In an ideal world I would use an 8 port reader but the polling between antennas offset the advantage of not worrying about interference.

More and more I think that the issue may actually just be the mats (not the concept, just mine!)

[Joe Fertsch]

Thanks for the info   - I have fiebot and race result mats   personally I have not been impressed with the feibot mat.  I like everything about it except i dont get great read results so if I  need to use them i will always use an additional side antenna - i have heard the antennas are well made but the cables not as much   so perhaps they can be changed out    Like many people I have a lot of money in different mats ( I have two Race Results and two Fiebots ) but honestly I feel I get equal or superior results using panel antennas.  Currently I use an aluminum truss with antennas on the side and and 4 above on the truss .   It may be overkill but it does work however you requires a bit more time.   Just my 2 cents  - Hope it helps