What are the possible reasons an input might trigger?

[Sbuffington]

I am haveing trouble with my digital I/O.  I'm using the 7334 with the UMI for the motion, and a third party breakout for the digital I/O.  I have 1 cable running running approx. 15 feet from the PC to a controls box with the stepper drives, power supplies, contact bolcks, and relays.  The one cable has 12 1/2 pairs of 24 awg conductors with a braided shield.  This cable connects the controls box to the UMI, and the thrid party break-out.  I'm experiencing intermittent problems with the motion control.  Our application is basicly a vector move on ax X axis, and a rotating move on the y axis at the same time at different rates.  There is a labview front panel that handles all the funtions of the program ie. reset, home, start, stop, and jog.  I also have 4 input buttons on the machine, and an indicator light.  The machine buttons are home, jog, start, and stop.  The labview front panel works flawlessly, but when I connect the cable to the third party I/O board I'm getting intermittent home, and stop inputs from my buttons.  Any thoughts?

[iZACHdx]

Hello,

Have you investigated the signals in question to the point where you know where the signal is coming from? Basically, we're looking to isolate the problem to a specific component of you system so that a closer look could be taken at that piece of hardware.

-Zach

[Sbuffington]

Hi Zach,

Thank you for the responce.  We may be on to the solution.  The inputs are close to a heat source.  I had put silicone button covers that sealed them from resin.  Seems that the pressure from heat was actually depressing the buttons.  We put small slits in the button covers, and this seems to have solved the problem.  I will keep you posted.