On Thu, Feb 3, 2011 at 10:13 AM, Viesturs Lācis <viesturs.la...@gmail.com> wrote:
> My waterjet machine has ultrasonic sensor that outputs 4-20mA analog > signal, I have microcontroller which converts that to 0-10V analog > signal (please, do not make my mistake and just get a sensor that > outputs 0-10V directly), then comes voltage-to-frequency converter and > then the frequency signal goes to EMC2 Wouldn't the 0-10V output be vulnerable to noise from the plasma arc? Both the current loop and frequency should be fairly noise-immune, so it seems to me that the best choice would be a direct frequency output, then the 4-20mA and the voltage output, in that order. How important is the height control? If not very, would it work to have a retractable pogo-stick for initial height setting: - solenoid deploys a pogo stick downwards alongside the spindle (jet head/plasma tip) - controlled downward Z jog until contact with material (or even a contact closure of a microswitch on the tip of the pogo stick) - retraction of the pogo stick for the work cycle ------------------------------------------------------------------------------ Special Offer-- Download ArcSight Logger for FREE (a $49 USD value)! Finally, a world-class log management solution at an even better price-free! Download using promo code Free_Logger_4_Dev2Dev. Offer expires February 28th, so secure your free ArcSight Logger TODAY! http://p.sf.net/sfu/arcsight-sfd2d _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
