with shielded wire, do not forget to ground the shield only on one side ! http://en.wikipedia.org/wiki/Ground_loop_%28electricity%29
Bruno On 09/03/15 01:13, emc-users-requ...@lists.sourceforge.net wrote: > Date: Sun, 08 Mar 2015 19:11:11 -0400 > From: Neil<emc_d...@narwani.org> > Subject: Re: [Emc-users] Missing/incorrect steps > To: Bruce Layne<linux...@thinkingdevices.com>, "Enhanced Machine > Controller (EMC)"<emc-users@lists.sourceforge.net> > Message-ID:<54fcd70f.4020...@narwani.org> > Content-Type: text/plain; charset=utf-8; format=flowed > > The ones I have are at least 5 years old and do have optoisolated > inputs. I'm not aware of the specifics of the -NR version, but the > datasheet for the ones I have says "The step clock (SCLK) and direction > (DIR) inputs are buffered using Schmidt triggered buffers for increased > noise immunity ...". > > I am providing a 5V opto supply to the IM483s with a homebrew switching > PS, so wondering if noise on that may be an issue. Also, I do see one > issue with the direct wiring I have now: if I'm only putting out 3.3V > from the step/dir signals with 1.8Vp-p of noise, and it has the 5V > pullup, then the opto input LEDs are seeing signals of 4.2V and 2.4V > which may be enough to be detected as on/off pulses. > > Yes, the noise is the problem, but translating my parport signals to > clean 0V-5V signals should be a major help here. All seems to be wired > and working fine, except for the occasional noise. Only reason I'm not > using shielded cable is because I don't have any. I'm going to find some > USB cables I can hack up and try those. > > Cheers, > -Neil. ------------------------------------------------------------------------------ Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
