On Wednesday 15 February 2017 13:45:38 dragon wrote: > The 20ma control circuit on the VFD is an analog control, where as the > parallel port pin is a digital (on/off) signal. You will need some > sort of hardware interface between the two to do a digital to analog > conversion.
I am currently running one of the Chinese fakes you see a gross of on ebay at any one time for small change over a $100 bill. No Modbus at all anyplace in it, just an assortment of analog and dir sigs needed. However, its opto-isolated, so for linear speed responses that fails rather badly at the low pwmgen percentages because the opto-isolators are too slow. But with a Mesa SpinX1 ($18) between them, I have quite linear speed control, and the SpinX1 helps to isolate the VFD's switching noises too. I haven't fully optimized the VFD yet, but I can reverse a 40lb chuck turning 200 revs in about 1 rev after making a locking collar so the chuck won't unscrew itself. It will do it even faster. That will do rigid tapping rather nicely, so I'm a happy camper. Motor is a 1hp 3 phase 230 volt I'd bought two of at a recycle facility here in town for a $50 bill (and no, I wasn't armed), lathe is an old Sheldon 11x36. This VFD is a 1.5hp rated model. Seems quite bulletproof. I am not saying this is the only way, but it works for me. And I am running it all with a Raspberry pi 3b, and a Mesa 7i90 interface. I am not thru building the lathe to fully operational yet, and progress is slow ATM, with my afternoons tied up visiting the wife, who is currently in rehab about 20 miles away, getting used to a replacement hip. > On 02/15/2017 12:36 PM, Valerio Bellizzomi wrote: > > On Wed, 2017-02-15 at 10:22 -0800, Kirk Wallace wrote: > >> On 02/15/2017 09:25 AM, Valerio Bellizzomi wrote: > >>> Hello, > >>> > >>> I have an Toshiba vfd which has a current signal input (max 20mA), > >>> is that compatible with linuxcnc to be wired to S gcode command ? > >>> > >>> > >>> Thanks. > >> > >> Briefly, mostly yes. > >> > >> The S word has an associated HALpin. This HALpin can be HAL > >> connected to another HALpin that handles the hardware that can > >> affect your VFD speed > >> > >> function. So: > >>> S word --> S word HALpin --> 20ma HALpin/20ma HALcomponent -- 20ma > >>> hardware ^^ g-code/MDI -- .hal configuration file -- HAL .comp > >>> component file -- wire from hardware interface to VFD > >> > >> In other words, LinuxCNC already has a S word HALpin that you can > >> use to connect your 20ma interface to. You would need to decide > >> what hardware you want to use and look for or make the HAL > >> component (software). > > > > I am not aware of any interface hardware , I thought to wire one > > parallel pin to the vfd, but I might be wrong. > > > > suggestions? > > > > > > > > > > -------------------------------------------------------------------- > >---------- Check out the vibrant tech community on one of the world's > > most engaging tech sites, SlashDot.org! http://sdm.link/slashdot > > _______________________________________________ > > Emc-users mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
