On 4/15/2012 11:02 AM, Peter C. Wallace wrote: > On Sat, 14 Apr 2012, Kirk Wallace wrote: > > >> Date: Sat, 14 Apr 2012 14:45:40 -0700 >> From: Kirk Wallace<kwall...@wallacecompany.com> >> Reply-To: "Enhanced Machine Controller (EMC)" >> <emc-users@lists.sourceforge.net> >> To: LinuxCNC Users List<emc-users@lists.sourceforge.net> >> Subject: [Emc-users] G540 Test Update >> >> I set up Dan's G540 today and used it with three different ports. A >> motherboard port which worked okay, but showed a bit of a saw toothed >> wave form, so it seems the G540 pump input draws a fair amount of >> capacitive load compared to the pin 16 output source capability. >> >> I then used a Rosewill dual port PCI card with a Moschip 9815 on it. >> http://www.datasheetarchive.com/indexdl/Datasheet-082/DASF0042609.pdf >> >> I got a pump signal out of it but the the ON voltage didn't get much >> above one volt. Switching from SPP to EPP didn't make any difference. >> >> I then used a Startech dual port PCI card (bottom of page): >> http://wiki.linuxcnc.org/cgi-bin/wiki.pl?Startech >> >> and got the pump to work in EPP but not SPP, which was expected. >> >> Using a 1k Ohm pull up to +5V on the Rosewill card got the G540 to show >> a green LED, but the wave form was similar to the non pull-up wave (OFF >> = 0v, ON = 1V) but with an upward ramp during the ON time that got into >> the 2 Volt range. There was no change between SPP and EPP. A 660 Ohm >> resistor pulled the ramp up higher, but 5V / 660 Ohms = 7.5 mA and is >> starting to get into an amp range that could get interesting for pin 16. >> >> With my current bench setup, I need three hands to get a wave form on >> the oscilloscope and take a picture, so I'll need to upgrade my setup in >> order to post the wave forms. I hope to do that soon. >> >> What comes to mind from my first test is that the Roswill may never work >> with the G540 without an external pull-up. These 9815 based cards are by >> far the most popular, so either Mach3 people are not using PCI cards >> with the G540, or Mach3 is doing something other than setting EPP mode? >> >> I found that Stepconfig worked well for setting up the pump. There is a >> G540 short cut button that seems to enter the signal timing and some >> other settings, but I needed to change a few pin assignments. Stepconfig >> sets up the pump to come on when LinuxCNC is out of E-stop. I don't see >> a problem with this, but if needed, it's easy to change the >> configuration files to get full time pump regardless of e-stop status. >> >> -- >> Kirk Wallace >> http://www.wallacecompany.com/machine_shop/ >> http://www.wallacecompany.com/E45/index.html >> California, USA >> >> >> ------------------------------------------------------------------------------ >> For Developers, A Lot Can Happen In A Second. >> Boundary is the first to Know...and Tell You. >> Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! >> http://p.sf.net/sfu/Boundary-d2dvs2 >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users >> >> > > > This does show the the G540 charge pump circuit needs a re-design. Theres > really no reason it should not "just work" with _any_ parallel port in any > mode. > > (if you look at the various Mach forums, a lot of people just gave up and > turned the charge pump off) > > Peter Wallace > Mesa Electronics > >
I didn't think about that "solution" to the charge pump issue! Not to put down the Mach3 forum folks, but many of them are "problem avoiders". When they run into an issue they are perfectly content to simply ignore the problem rather than rant about it (they typically can't fix the issues since the software is closed source.) The list of broken features or bugs in Mach3 is extensive and it has been for years and it doesn't seem to be improving. The LinuxCNC developers, in contrast, would lose sleep over the same bugs, rather than suffer the embarrassment. So in retrospect, I would expect that the typical Mach3 users answer to a G540 charge pump issue would be to simply "turn it off". All is not well in Mach3 land. Dave ------------------------------------------------------------------------------ For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
