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Unread 19-05-2003, 11:17
Dave Flowerday Dave Flowerday is offline
Software Engineer
VRC #0111 (Wildstang)
Team Role: Engineer
 
Join Date: Feb 2002
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Quote:
Originally posted by JasonStern
If IF does enable all 40 channels for comp, doesn't that mean the mobile modem has to scan through 40 channels looking for a signal <i>every</i/> time as it doesn't know if the extra channels are enabled ahead of time?
Shorting that pin on the Competition Port enables an additional 4 channels as you have mentioned. However, when hooked to the Arena Controller, there is some other method that IFI uses to enable all 40 channels. I don't know how, but I'm assuming it's done with the serial link that exists between the OI and the arena controller. If you look at the arena controllers (they're located in a column that sits underneath the shelf that you put your controls on and look very similar to an OI) when you're at a competition, each one has it's assigned channel number shown on the 7 segment displays. At all the regionals where I've taken the time to look at them, they have not used any of the 5 channels that are available to everyone by using the competition port dongle, presumably to avoid interference from the team s that inevitably run their robots in the pits without the tether. So in answer to your question, yes the robot controller does indeed scan through all 40 channels each time it's powered up or loses signal.

Additionally, the radio modems themselves lock out access to all but 5 channels in the default mode. There is a special command that must be sent to the modems to unlock the other 35 channels.

This year IFI had a new tool they used at the competitions that monitored all 40 channels to watch error rates as well as to watch for people powering up in the pits. If you ever looked at the scoring table, there was a laptop connected to two radio modems. The display said something to the effect of "Innovation First Scanner" and it showed all channels that were actively being used. The 5 "user accessible" channels were highlighed in a different color to indicate that someone was using them in the pit area.