2007 tether and program cable question

[Alan Anderson]

Originally Posted by vhcook

...we used a short bit of ribbon cable with serial connectors on both ends,...

That's a reasonable idea, but take care when doing this. The tether connection supplies power to the OI, and can fry the wire if your ribbon cable isn't up to the task. The year before I came on board with the team, the robot had extensions on the tether and programming connectors so they would be easily accessible. At some point when testing it out in the off-season, the OI pulled a little too much current and melted the insulation off one edge of the cable. I now know exactly which pin carries the power.

[artdutra04]

The program cables and program cables have exactly the same wiring; the only difference is that the tether is a female<>female cable, and the program/radio cables are male<>female cables. All you need to do to extend either the tether or program cable is to just add another program cable onto it - no modifications necessary.

[whytheheckme]

Originally Posted by artdutra04

The program cables and program cables have exactly the same wiring; the only difference is that the tether is a female<>female cable, and the program/radio cables are male<>female cables. All you need to do to extend either the tether or program cable is to just add another program cable onto it - no modifications necessary.

I'm pretty sure that the tether cable reverses the Tx and Rx lines... But I could be wrong. But you are right in the sense the the program cable is simply an extension cable... and can be added to the tether cable with no effect.

Jacob

[Qbranch]

As far as I know the teather cable is just a Null Modem DB-9 Cable... meaning, yes, the TX and RX lines are switched along with (I believe) the carrier detect and ready to send lines.

always seems like I get to the point of getting my scope out before I figure out I just have a non-crossover cable where i need a crossover or vice versa...

-q

[Dave Flowerday]

Originally Posted by whytheheckme

But I could be wrong.

Yup, you're wrong - it is straight through. A simple gender changer on the end of a regular serial cable will convert it into a tether - we do this all the time.