Finishlynx Connection Box (C-Box)

You don't need the C-box to do any ethernet tasks, ever.  I used to have a waterproof box for the C-box that contained it, and I'd swap the cords to the switch or the computer, but I did away with that a few years ago when I made my own custom cable to split the signal from the C-box connection out of the camera to my radiolynx (on my older cameras).

There's very little C-box purpose now, save someone using photoeyes or a maybe a wind gauge. (and yet I keep one with me someplace in my van at all times...)

Thanks this is very helpful.  We have a bare-bones timing system where we pull a wired start sensor to the start lines.  So if understand things correctly, the only purpose of the large DB-17 cable from the camera to the C-box is to send the start signal back to the camera and then through the ethernet to the computer?   We just don't have the money for a wireless start sensor so I think I'm stuck with the C-box for now.

Correct (although it's a DB15 connection, unless yours is somehow different than all the ones I've seen!)

You could easily try your hand at an adapter if you want, I just used a multimeter in continuity mode to determine the pin out and saved a bunch of cabling.

Yes its DB15, sorry I'm new to this!  I like your idea of an adapter, as I would like to make my set up as possible. 

Thing I'd worry about for this is that there would be more possible tension on the camera.  I think I'd rather run to the Cbox and fasten it to something, that way there's minimal chance that a starter going across the field to the 200 start could somehow yank something hard and affect the setup.  But when you do go to Radiolynx, this is an easy adaptation to make.

Yes I'm hoping that the school finds some money to get radiolynx.  It's just so expensive!  The wired start is a hassle as it requires another volunteer to hold it or to have the starter deal with it.  Without a volunteer we have a bunch of false clock starts because the starter inadvertently will bump the sensor. I'm also super nervous about the camera getting yanked over so as I precaution even with the C-box I've been driving a stake into the track infield and duct-taping the data cable to the stake.   This has been a nice project for me as a school volunteer, much better than selling hot dogs in the concession stand. Thanks again for your help.

why don't you put the sensor on a stand of some sort, that the starter can stand near - and then you don't have to worry about the starter accidentally banging it ? That's been our solution even with radiolynx, because some of the starters are just not very careful...

Yes that would work, in theory.  However, my experience has been some starters are very particular about where they stand to start the races.  Our best solution has been to get a youth volunteer to follow the starter around, and ask the volunteer to be careful not to bump the sensor.  Second best is to nicely ask for the starter to cable tie the sensor to the gun, which leads the false elecronic starts.  The worst situation is when a starter wants to stand on the outfield for some races but the sensor is on the infield.  Then we have to drag the wire across the track behind the athletes.  Wired start sensors, are a hassle. I'd even say borderline impractical.  I understand there's no DIY wireless system for Finishlynx so were stuck with a $2,000 upgrade or pulling the wire around.  

Here is some technical Diagrams I made awhile ago, you could easily make a DB15 -> XLR adapter. The Ethernet ports on the C-Box allow a crossover, I've never needed the crossover aspect, just used occasionally to extend cord Length.

Thanks for posting.  This is very useful information. 

Sorry to piggy back this, I am looking to directly wire a photocell into the back of the camera on the DB15 port. From the diagrams linked above (really useful, thank you for putting these together)
It looks like pins 9-15 on the DB15 are all ground? Any idea which of the other pins would be best to connect an input from the beam photocell into?

it looks like this:
15 - GND
8 - +Power
9 - GND Signal
7 - Input signal

Updating for anyone that comes back to this in future.

You can wire any 12V DC Normally Open contact closure output and assign it as a beam in FinishLynx, to do this you need to follow the wiring layout on my previous post. Just plug that directly into the DB15 on the rear of the camera "connection" port.