Yes, and I need to start a new thread as new info has been received. JT
On 1/9/2016 7:49 PM, Dave Cole wrote: > Just saw your message. > > If you keep the VFD powered off, do you still have noise issues ?? > > Dave > > On 1/4/2016 5:19 PM, John Thornton wrote: >> I have 3 DC power supplies in the drive side, a 5vdc, a 24vdc, and a >> 170vdc. >> >> The 5vdc power supply on the 0v side reads 37.6 ohms with the 0v and 5v >> sides connected to the 7i77 5v plug. The 7i77 is the only thing it >> powers up. When I unplug the 7i77 0v reads open so there is a path >> through the 7i77 5v to ground. >> >> The 24vdc power supply is for the limit switches and push buttons. It >> reads open from 0v to ground. >> >> The 170vdc power supply is a bridge rectifier with a large blue cap and >> a power resistor. See the photo in the link of the current panel. I >> can't tell which side should be 0v but both sides measure 0.65M ohms to >> ground. I don't know if that is reading back through the bridge >> rectifier or the drives. It only powers the three axis drives. >> >> Current panel layout http://gnipsel.com/images/bp-knee-mill/bpel06.jpg >> >> JT >> >> On 1/4/2016 10:48 AM, Bertho Stultiens wrote: >>> On 01/04/2016 05:34 PM, John Thornton wrote: >>>> Well I grounded X2 to the main ground and when I started LinuxCNC and >>>> started to home I got the flurry of sserial errors. So I thought about >>>> it for a bit and maybe the ground from the computer case to the ground >>>> block was creating a ground loop so I took it off. Started LinuxCNC and >>>> immediately go a flurry of sserial errors which locks up LinuxCNC. Mind >>>> you this is with the 7i77ISOL card between the 5i25 and the 7i77 which >>>> is supposed to block any noise in the sserial communications. The X2 to >>>> ground has to go... >>>> >>>> I do have a 7i92 to test out... >>> My guess is that you have more than one (ground-)loop. You also need to >>> check how the 0V (DC) line interacts with other devices/converters etc. >>> wrt. ground and see whether any of them also hook-up to ground somewhere >>> along the wiring, PCBs or supplies. >>> >>> The second type of loops can be (entirely) in the 0V (DC) connection(s) >>> where multiple paths, with different impedances, impair the integrity of >>> the signal lines. You need to check how the different DC supplies >>> interact with the connections as they are. The problem often becomes >>> visible when you have both high- and low-power devices connecting and >>> running on the same supply and have the 0V (DC) connected so that it >>> (can) create(s) a loop. >>> >> ------------------------------------------------------------------------------ >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ > Site24x7 APM Insight: Get Deep Visibility into Application Performance > APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month > Monitor end-to-end web transactions and take corrective actions now > Troubleshoot faster and improve end-user experience. Signup Now! > http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
