Digital Sidecar problem

[Jon Stratis]

Near the end of the day today, when we had stuff finally working like it was supposed to, we discovered a rather odd problem with one of our DSC's. We have a limit switch that was hooked into the digital I/O 6 port, while most of our motors were being driven from the PWM ports on the same DSC. Well, whenever the limit switch was closed (linking signal to +5V), all the motors would stop, with blinking orange lights on the victors/jaguars. After finally tracking down the problem, we pulled out the PWM cable for that port and stuck in a new one, hooked up to a new limit switch (in order to determine if there was a short somewhere in the existing wiring) and saw the same problem. After looking into it a while, we noticed the +5V LED went off whenever that limit switch was pressed.

We moved the switch to a different Digital I/O port, and everything works just fine now, but i was wondering if anyone else has seen a similar problem with the DSC?