This is probably been answered; But as the new guy, please indulge me. I have a VVD and every thing on the drive works fine. I can controll the speed, turn it on and off , use the over rides. But I keep getting random false limit switch trips, I think it has to be noise from the VFD because if it's not running the program runs great, but when the spindle is running I may get 1 trip or 16 trips. Any ideas?

Thanks

If using the parallel port you could try increasing the Debounce Interval on General Config page.
If using an external controller then it may have some filtering options in the plugin.
Hood

make sure that your power cable from the vfd is not running alongside or near the limit switch wires. As they are usually 5v they can be affected by the vfd.

Thanks for the replies, I pushed up the debounce time and it cut out most of the false tripping, then I changed the switches from n/c to n/o and that took care of the rest.

NO switches for limits/E-Stop are not the best as if something goes wrong (wire comes loose etc) then you will never know until you need them and by that time its too late.
Much better to shield and properly ground the shields if you are having issues.
Hood

Thanks again for the reply. I have a safety back up switch that is also in the circuit. The main limits are non contact prox.