Discussion: SportIdent question

I have SI-6 stick and I have noticed I sometimes get signal even if my stick is not in the hole. It seems to be enough if it is close and touches the punch unit near the hole.

That made be think what happens if two competitors tries to punch almost simultaneously with same unit. First someone with fast and more sensitive SI-6 fails to get stick in the hole but the stick gets close enough for communication. Some milliseconds later someone with old slow SI-5 gets his stick in the hole. Will there be flash & beep at all and if there is who gets the punch mark? Both? Has anyone tried (can someone confirm) is it possible sometimes SI-6 gets the punch and SI-5 not. It could explain some "stick was in the hole and there definitely was flash but still got no punch" incidents at crowded last controls.

You should just punch the person with the SI-6 stick and stick him in the hole. That'd clear up matters considerably.

Sounds like a question best answered through experimentation.

It's a shame tRicky's got an SI-5, I thought he'd just volunteered.

I had enough issues on the weekend trying to discern which tag was beeping in the start brick - mine or the person punching in the one next to me.

We have no SI equipment here, so can't do any experiments myself. I hoped someone had already tried it. Or someone with equipment at hand could do some experiments. If it is as I believe (SI-6 and SI-9 sticks can kind of "steal" punching turn from SI-5) it would be good to know. Then SI-5 users would know to punch again if there is lot of "interference" and not blindly trust that flash/beep.

Will do some testing tonight.

feet and BorisG tried to finish punch simultaneously at the Highlander, but were unsuccessful.

Thanks. The simplest test would be keeping one stick close enough to get the beep signal (but not in hole). While the unit keeps beeping put an other (SI5, should be tested with SI6 too) stick in hole and take it back after one flash and see did it got a mark or not.

If units stops beeping when second stick goes in or second cards always gets punch mark too, then one could try playing with timing, putting second card in about same time or a slightly later than the first one.

At our local event someone left his SI tip in the SI station hole (only tip, I think runner didn't noticed that tip snapp off) and after that there was impossible to other runners to punch, until tip was removed.
I think SI station is single channel device, and when one SI stick seizes communication, other sticks can punch only after first stick is removed.

This isn't directly related to the original question, but there is another simple explanation for "it beeped but didn't record" complaints: When a unit's battery is disconnected and reconnected, it beeps and flashes. Thus, a poorly connected battery can cause a unit to beep when it is knocked or otherwise moved.

Earlier this year, the MOA had a unit with a loose battery (not well soldered) that would sometimes beep when it was jarred, picked up, or moved slightly. Most of the time this unit simply didn't work and fortunately there were no "it beeped but didn't record" incidents. However, someone punching it in the forest certainly could have moved it enough to make it beep/flash.

The one thing I don't remember is whether the unit beeps twice upon startup. (I seem to recall a "beep-beep" sound.) However, even if the startup beep is different from the punch beep, you can't reasonably expect participants to distinguish between different beeping sounds.

Besides a poorly connected battery, I suppose that a defective battery or a faulty main board could cause the same thing to happen. And if the defect is 'just right', the unit might even work 99.9% of the time, causing the fault to go unnoticed.

I finally got around to trying this. I was pretty sure what the result would be but wanted to check - it is a single channel device and if one SI-Card is in, another will not start communicating until it is removed, this I found to be true. If two SI-Cards approach side by side and hover near the hole, I couldn't make either register, I suspect it is unable to communicate with either because of the presence of the other, but of course there was no beep/flash in this instance. I found no difference with card 5s, 6s, 9s or even the credit card style cards which even when placed on top of one another either the lower one would register, or neither (neither resulting in no beep/flash).

A loose battery would indeed cause random beeps, but each time it beeps in this case it indicates the station has reset and the clock will have lost its time, so you would know in this case that something funny was going on because the split times would be rubbish.

I suspect the vast vast majority of mispunches at last controls are human error. Just go and stand near a last control and watch how many people attempt to punch without looking for the flash - with multiple stations they hear a beep and off they go.

Perhaps SPORTident should've continued the development of their LCD version (Card 7). I do like the screen on the later Emit cards for a bit of simple reassurance that the punch did go on the card. If you mispunch with one of these really you only have yourself to blame.

So thats what the 7s are! The documentation has scattered info referring to fields in the 6 that could hold control descriptions for each control also.

From my investigations, it looks like the 5s use a different modulation scheme from the 6s, and maybe another for the 8s. Most of the radio in the units seems to be software, rather than a dedicated transceiver IC. My theory would be that it detects card presence and then switches to the modulation scheme for that card, which means no other card could be talked to until that card is removed and it redetects a new card. What about two of the same card series in the hole at the same time? I would guess that it would randomly pick one to talk to and complete a transaction with that card, and then require both to be removed before talking to the second one on reinsertion.

So Jagge's original question remains, I think: put an SI-6 next to the hole, but not in it, and hold it there so that it starts beeping repeatedly. Now bring another stick (any kind, I guess) and put it in the hole. Will the unit continue to beep, perhaps making the person with the second stick think that he has punched? Or will the beeping stop?

I just tested that. The station remains beeping until the first stick is removed. You can not punch with a second stick while it is still beeping for the first one.

Interesting - I was unable to get the unit beeping unless the SI-stick (tested with both 6 and 9) was in or completely covering the hole. The end result was that I couldn't physically punch with a second stick regardless of how it would handle the electronics and signalling.

I had the stick in the hole to make it beep when I was testing before. With the hole occupied another stick had no effect.

I just tried with an SI-6 on the back of the unit, so I can get it to beep without it really being in the hole, just laid flat. The back is easier since it is much closer to the coil.

I then put a 5 into the top of the unit all the way in. It stops beeping for the 6, and never beeps for the 5. When I remove the 5 it starts beeping again for the 6.