John, Yikes! You mentioned to me to check my shielding on the limit switch wiring. It seems that will help, but something else is going.
You had mentioned/requested a picture, so I finally got around to putting them up here: http://imgur.com/a/d1jqu Those pics were during the retro-fit, so the covers are now on the wire ducts, etc. and it's a little cleaner. But, still noisy. Bertho - What you state about the different power supplies is a fear of mine as I have a +-15vdc Power supply for the Op-amps for the West-Amp servos, an open frame type 24Vdc power supply, plus the 5vdc power supply I added for the 7i77. Also, I don't have my PC in a PC case, open frame w/ the 5i25 held in by friction (i know, I don't like this either - need to bend a clamp). But, the PC power supply also could factor into the ground loop equation. I have mine mounted to the door of my enclosure. I did buy a rasmi filter off ebay for the GS2 VFD and it should be in end of the week. I feel like it's really hard to trouble shoot because you have the 5vdc to power the 7i77 and then limits, relays, etc are presumably run off 24vdc. So, plenty of ground loop possibilities, especially w/ the encoders and limits being wired up on the original wiring. Plus the addition of the PC to the cabinet... Sorry I don't have a good suggestion... It seems like waiting for micges and the software update is as good an idea as any... Mark > Date: Mon, 4 Jan 2016 17:48:26 +0100 > From: Bertho Stultiens <ber...@vagrearg.org> > Subject: Re: [Emc-users] Rewiring the BP > To: "Enhanced Machine Controller (EMC)" > <emc-users@lists.sourceforge.net> > Message-ID: <568aa25a.1040...@vagrearg.org> > Content-Type: text/plain; charset=windows-1252 > > 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
