Tether heating up!

[Shu Song]

Today, when we first hooked up the RC to the OI with tether today, the serial cable heated up to burning. I don't think the OI or the RC is damaged by this, though. The entire circuit was hooked up correctly.

here's what we did:
We connected main circuit breaker to the fuse panel, put coinnected power to the RC to the fuse panel and put a 20 amp fuse in there. We hooked the battery up to the circuit breaker, put the tether from RC tether port to OI tether port, and turned the power on. For a few seconds, everything worked, but after a few seconds, someone felt the tether cable get really hot and we saw the OI lose power. We quickly disconnected the tether.

We tried doing this again with another tether and the same thing happened. Has anyone else had this happen to them? How do we fix this?

PS we are now giving power to the OI through the power adapter and communicating with the radio. But the radio is giving us a radio fault and we fear that it might be related to the tether burning up and (if you gus remember) the OI displaying info one digit at a time the other day.

Please excuse any poor grammar, I'm typing very quickly right now.

[devicenull]

Go get some compressed air, and blow out every connector on the RC, fusebox, and OI. Thats just to make sure there's no metal or other things in the connector. Try a different tether cable if you have one.. Hooking up the back up battery at the same time *might* help things..

If none of this helps the cable heating up, stop using it and contact Innovation FIRST. You don't want to let the magic smoke out if its preventable.

Edit: Now that I think about it, I would contact IFI before you do anything more with the controller. If you can avoid using it, I would. Post on their tech forums, or call them.

Check your battery voltage too, it shouldn't be too high.. but if its higher then it would normally be that could cause it..

[Dave Flowerday]

Originally Posted by TierraDelDiablo

PS we are now giving power to the OI through the power adapter and communicating with the radio. But the radio is giving us a radio fault and we fear that it might be related to the tether burning up and (if you gus remember) the OI displaying info one digit at a time the other day.

Do you have any custom controls plugged into your OI? Either a button box, a rewired joystick, an autonomous/disable dongle, etc?

Something I would try would be to unplug everything from ALL ports on the OI except for the radio modem and power cable and try it. See if you're still having the radio fault.

[lupjohn]

Check to make sure that the chassis is not at +12volts. Somewhere you are shorting +12volts to ground via the cable shielding on the rs232 tether to ground on the control console. Had the same problem in 2003 and have saved the cable to make sure that this error is not repeated. LRU.

[Al Skierkiewicz]

Shu,
I have to go along with Dave on this one. Remove any and all devices connected to the OI and try the tether again. If it still gets hot, I am guessing you have a defect in the OI. These things happen and IFI is pretty good about getting you fixed up. Contact them as soon as you can. They will get real busy when regionals start up.

[russell]

The tether overrides the radio modems automatically. If you have the tether hooked up it is used for all comunications, which is probably why your radio modems dont appear to be working. I would try unplugging everything from both ends except a battery on the RC then slowly plug things back in one at a time to try to isolate the problem. It might take a few hours, but if it took nine hours but you dont fry anything and you find the problem, then you would be saving a hundred bucks an hour over frying it and having to buy a new control system. Innovation First totally rips you off on those. All they have is two chips in them that cost seven dollars each without a bulk discount! Then there are probably a few capacitors and such for measuring the analog inputs, but it certainly isnt worth the 500 dollars they want for a new RC.

[Dave Flowerday]

Originally Posted by russell

Innovation First totally rips you off on those. All they have is two chips in them that cost seven dollars each without a bulk discount! Then there are probably a few capacitors and such for measuring the analog inputs, but it certainly isnt worth the 500 dollars they want for a new RC.

Wow, that is so far from the truth... You do realize that there is a fixed cost associated with any product which is the engineer's time to design (and write software for) said product? This is very expensive, and IFI only gets to ammortize that cost over a few thousand units. The cost to create the hardware design & software though is about the same as something that another company may sell millions of for $100 apiece.

IFI puts out a very high quality product year after year and goes out of their way to meet the unique needs of FIRST. You can't get that from just any old company.

Why do you think a copy of Windows XP costs $199 (or whatever it is these days)? It's only a 10 cent CD with a thin manual, right? Wrong - you're paying for the development effort that went into the software contained on that CD. With IFI, you're paying for the development that goes into the RC and OI, as well as the field control system that integrates so well with them.

[BrianBSL]

Originally Posted by Dave Flowerday

Wow, that is so far from the truth... You do realize that there is a fixed cost associated with any product which is the engineer's time to design (and write software for) said product? This is very expensive, and IFI only gets to ammortize that cost over a few thousand units. The cost to create the hardware design & software though is about the same as something that another company may sell millions of for $100 apiece.

IFI puts out a very high quality product year after year and goes out of their way to meet the unique needs of FIRST. You can't get that from just any old company.

Why do you think a copy of Windows XP costs $199 (or whatever it is these days)? It's only a 10 cent CD with a thin manual, right? Wrong - you're paying for the development effort that went into the software contained on that CD. With IFI, you're paying for the development that goes into the RC and OI, as well as the field control system that integrates so well with them.

Agreed. Also, I bet if you were to spec out every item in that RC you would approach the $100-$150 mark. I'm not one to ever say that IFI is a great deal, but its not $14 to make the thing either.

[Al Skierkiewicz]

Originally Posted by russell

Innovation First totally rips you off on those. All they have is two chips in them that cost seven dollars each without a bulk discount! Then there are probably a few capacitors and such for measuring the analog inputs, but it certainly isnt worth the 500 dollars they want for a new RC.

Russel,
I am not sure what IFI product you may have opened but it was not the RC. Last time I opened one, I was surprised at the quality of the component choices and the design of the electronics and board. Rarely has a company continued to improve designs annually, in such a limited marketplace. Whatever IFI is realizing in profit from this product is small compared to what goes into it. Every effort has been made so that rookie teams and veterans alike cannot paint themselves into a corner with electrical design, interface electronics or software. The RC, OI, Victors and spikes are all high quality items and I am proud to use them. IFI in no way is attempting to "rip off" anyone and compared to the support they give at all regionals and the Championship I question whether they make any money from FIRST products at all. IFI is a company I would be proud to work for and everyone should hold up as an example of a quality business.

[russell]

Ok, I..... dunno wut the word I am looking for is (submit maybe? I dont know) to your combined superior knowledge. All I know is what I have read in the control system documentation, which states that the Robot Controller uses two PIC microcontrollers, one for master code stuff, and the other for user code. So really I dont know. What I do have to say I know is that the OI and radio modems work well, and the radio modems anyway (I dont know how much they want for an OI) are worth what you pay for them, and Innovation First does have excellent support for their products which do work.

Perhaps I should restate my original assertion. If all you want to do is build a robot (I am into robotics in general, not just FIRST), then for the same amount of money you could get a far more powerful system better suited to your needs. However as has now been pointed out to me the Innovation First stuff is good for a FIRST competition, and does work well. I do especially like the radio modems abilities as I have had quite a number of projects go nuts due to radio interference (I live right next to an airport).

Anyway, I stand corrected,

Russell

[Mike Hendricks]

Originally Posted by russell

However as has now been pointed out to me the Innovation First stuff is good for a FIRST competition, and does work well.

Not to mention .. IFI controllers arent limited to FRC competitions. Alot of other combat robot competions requiring the use of IFI controllers (since the competition uses IFI arena controllers). Then theres the Victors .. which are also used in many combat robot competitions, and are almost 1 of a kind. Very few speed controllers can support the surge and continuious current loads the victors can.

Going back to the issue at hand ..

I think a call to IFI is in order. I'm sure you could work out some arrangement for a swap with them (since the controllers are still under warranty).