Using 1 pair for start, headset & display board with ALGE

You might consider using a TIMY or COMET in Commander mode to manually input the times for the start. Just parallel another headset and amp off the single line for an operator.

That way the operator can verbally receive the time split, type it in, and display it independent of the starter.

The other way is to use live-timing.com and have the start display technician watch a smart phone and type the times in.

You are going to end up with too much data noise if you try what you are suggesting and the headset will end up being discarded.

This sounds like a very demanding event. Where is is going to be held?

You can use 2 sets of TAG Radio Impulse/Data HL670.

Sender at finish, sender/receiver chained with male/male DB9 in the middle and a receiver at start. You will need a MaleDB9 to banana in both ends for the TdC and DLine.

Be aware of the baudrates. Setting baud rate to 2400 will most likely increase range and decrease packet loss.

From the info 'Mouse' has supplied, it is hard to come up with suggestions. What kind of distance are you talking about as that will affect the possible solutions. When is the race?

It seems odd that the TED's did not function well as we use a number of TED sets without issue. We originally had concerns with all the different transmitters at the top of the hill as well as the terrain. Neither issue has caused problems so far. Was the TED, that you tried, a TED-10 or the TED-400?

Thanks for the replies.
FKP- it's not so much that it's demanding, it's a combination of (1) only having 1 pair, (2) on a mountain which is shaped in such a way that TED-400's don't work reliably (so I assume other brand transmitters as 2-way radios have issues also without a repeater) (3) where we need to transmit the serial feed to the top (there's only phone/data coverage at the top).

"You are going to end up with too much data noise if you try what you are suggesting and the headset will end up being discarded.": is it just the headset which would be compromised, or the start impulse also?

Rib Mtn Timer: we have 2 sets of TED-400's which I agree work well- we've used many times without issue. The problem on some hills is simply the local geography. In this case it's a MTB downhill, which starts a way behind the top of the hill, the signal simply does not curve far enough.

It may just end up that we run another pair on the ground, although if we can run a start impulse + RS485 on the same cable, that's an option, and we can find another way to transmit voice.
Thanks,
+M

Thanks 'Mouse' for the additional info. It is now a bit more clear. I can understand why the TED-400's are giving you problems. A couple of things you mentioned got me thinking a bit. One possible solution for the 'starts' would be to use your two TED-400 sets as a repeater type set-up. One could put one transmitter at the start with the receiver at a high point that both the start and finish could so to speak, see. The output pulse from receiver, at the high point, could be fed into the transmitter of the second TED set. Of couse you would have to have a little distance between the transmitter and receiver so the the transmitter would not over drive the nearby TED receiver. The second received would be down at the finish and receive the repeated start impulse. Between the the two TED sets you would introduce a 0.2 sec delay but it would be consistant. I don't know if anyone has tried something like this but maybe FKP or others might have tried something like this before.

The reason for asking the length of the cable pair you could use is to determine if some other data equipment would work for you. If the TEDs would work in the setup described above, then it frees up your pair for the use of both comm and data. Depending on the distance, you could look into using ethernet extenders which function over a single pair similar to DSL. The pair would be available for voice and the data would go over the DSL link. Once the link is established you could use a pair of 'ethernet to serial converters' to get the data to the start. We use the converters at our hill to get a dispaly board at our start as well as a VoIP link for our comm. over that 'DSL' link.

Hope this helps?

Look into the Microgate Linkgate radio system.

We use these for all of the different starts at the Diablo US Open MTB Downhill and Gravity Series with 100% success for 3 seasons now.

The 500MW Enc radios are great and have the BIB ID so that each racers number goes automatically into the timer and software if so configured.

Take a look at the demo we did for Winter Park Colorado who purchased this system for their MTB series. We had two ridges in between the transmitter and receiver and maintained 60% signal strength! You can race with 35%.

http://timingguys.com/eve/foru...31013442/m/991101414

Pretty impressive system that is easily configured for use in the summer with tripods and wheel bases instead of wooden photocell posts and a start photocell instead of gate.

http://sportstiminginternation...od_training_ski.html

We've used the TED's chained together before, at another location, for the start signals, and found it can work- some courses we've seen won't even work with that, but it's rare (and accuracy needs to be considered also). It's an option we'll consider.

Do you know if the start impulse and RS485 data can co-exist on the same pair?

(btw, the ethernet extenders are a great idea: would use that if I was doing a permanent install & will play with it if I get the chance)

From the info I could briefly gather off the Internet, since I have not worked with RS-485 yet, it appears that it does not really like shorts that a start impulse would put on the line. It appears that they build special circuits, into the equipment, to compensate for possible shorts. If a short was seen on the line, as in a start, data transmission is halted. I am not sure how rapidly it starts back up after the short is removed. Maybe something to experiment with.

As far as the ethernet extenders, the ones we use are relatively compact and could be moved around pretty easily. The start signal would have to be converted to an audio signal to be sent over the pair that the ethernet extenders are on and a relatively inexpensive VoIP link would be needed for the voice link between the start and the finish.

Thanks for that, appreciated.

Out of interest, what brand/model ethernet extenders & VOIP hardware are you using?

The Ethernet extenders that we use are from 'NetSys'. There are several different models depending on speed and distance required. I have tried one other manufactures Ethernet extenders but we seemed to have better luck with NetSys as one model allows you to lock in the speed once you determine the optimal speed.

As for the VoIP units, we have used the Linksys model PAP2T-NA. You need one unit for each end and a pair of units allows two independent voice channels. When the voice channels are set up they act as ringdown type phone circuits. We use a standard wired telephone headset at the finish and cordless wireless headset system at the start.

As with RS-485, the Ethernet extenders do not like shorts of the copper pair. The idea I have come up with, if you are unable to use the TED's for the starts, then one would have to come up with an audio link to transfer the start signal over your copper pair, with the Ethernet extenders on it. My thoughts are to have a tone generating circuit at the start to generate an constant audio tone to the finish in order to verify the pair is in tact. When a start pulse is generated the audio tone is interrupted to the finish and a detection circuit will see the interruption to transfer the start impulse at the finish. The circuits would be relatively simple and the delay would be extremely small and consistent.

Hope this helps.

The Linksys units are relatively inexpensive but the instructions that come with it are not the greatest for setup in the mode we use them. The information is out on the Internet and I spent many hours searching until I stumbled upon it. If anyone decides to obtain and use a pair of the Linksys units, please drop me a note directly and I can send you the information.

My email address is: ribspydrmn@juno.com

You can try using an directional antenna instead of the rubber duckie antennas supplied with the TEDs I have had good luck with a 3 element yagi pushing my low power microgate encoders a long way.

Lou..