On Tue, 2012-07-24 at 20:47 -0700, Peter C. Wallace wrote: ... snip > The latest G540 configuration uses a one output stepgen for the chargepump > due to that rather annoying G540 "feature" that the chargepump needs a > 10 KHz frequency which would force the use of a base thread if the bit was > just GPIO (dont know why 500 Hz would not have done, oh well)
I have gotten 1 kHz to work. http://wallacecompany.com/machine_shop/G540/g540_siig_1kHz.jpg http://wallacecompany.com/machine_shop/G540/ It depends on how hard the drive circuit can drive the G540 input. A buffer chip or transistor that can quickly drive the signal to 5 Volts and 0 Volts will be able to get more charge into the G540's pump capacitor and may get the frequency down to 500 Hz. http://wallacecompany.com/machine_shop/G540/G540_upper_bottom_z-1b.png > The chargepump stepgens are at the end numerically so dont interfere with > the G540s stepgen assignment (they are stepgen 8 (P3) and 9 (P2)) > > > There are a couple ways to get a square wave out of the stepgen. One is to > set > the position scale to 10000, set stepgen output mode to quadrature and > operating mode to velocity and finally set the velocity to .25 (this is .25 > instead of 1 because quadrature mode counts 4x as fast at step/dir mode) I just use a parallel port, buffer and HAL's charge pump component. http://wiki.linuxcnc.org/cgi-bin/wiki.pl?About_Charge_Pumps The G540 also has a pump bypass. See Step 3 here: http://www.geckodrive.com/g540-initial-setup-guide -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
