On 02/15/2017 10:36 AM, 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 ?
> I am not aware of any interface hardware , I thought to wire one > parallel pin to the vfd, but I might be wrong. > > suggestions? If you reply with the Toshiba model number, we could give you better information. Pictures and overview of your project would be even better. Basic direction an speed control can be done with just a parallel port and a few electronic parts. Here is an example: http://linuxcnc.org/docs/html/examples/spindle.html#_pwm_spindle_speed The PWM bits create an analog signal using a digital parallel port pin and switching it on/off in a way that effectively acts like an analog signal. This would go to your VFD analog speed or frequency input. This is only needed if you want LinuxCNC to control VFD speed. The example shows the PWM signal being connected to the parallel port pin 9. Sections 3 and 4 below the spindle section (2) connect the basic digital signals to parallel port pins 14, 16, and 17. Usually the VFD inputs are opto-isolators which are usually a floating LED and current limit resistor circuit. Common parallel port buffer boards are good for driving these inputs. A breakout board with opto-isolators is not needed. A nice thing about parallel ports is that add-on cards are cheap and you can add as many ports as your computer slots can hold. The down side is that parallel ports are slow, so the PWM signal will not have high resolution. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/ ------------------------------------------------------------------------------ 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
