Hi Charles, Sorry for the delayed response; end of year is always an extremely busy time. But thanks a lot for the answer.
Not yet. There have been experiments to show the benefit of using the > actual cycle time but for now the closest you can get is to use a Mesa > card (or one of the SoC+FPGA platforms) and use hardware triggered > timing. The software still assumes the servo period is exactly what was > requested, but since hardware captures the machine state at the correct > time (no software IRQ latency involved), that assumption is actually > correct (as it relates to the encoder and stepper positions used to do > motion calculations). :) > > Note: This is still somewhat experimental. It has been shown to work > but is not yet in general use. Testers welcome! > This sounds very interesting for my mill. That one runs a 7kHz servo thread. The servo amplifiers are used in torque mode and all control loops including glass scale corrections, notch filters to suppress known resonances, etc. are implemented in HAL. Would be a nice testbench. Where do I obtain more information about this? Regarding MachineKit: I have been toying with a Raspberry Pi 3 and ST Microelectronics SPI-controlled L6470 stepper drives: https://dl.dropboxusercontent.com/u/2762301/3dprinter/L6470_motorstroom_linuxcnc.png Works very well; the voltage-mode control of the motor combined with 128-step microstepping is very silent, the builtin trapezoidal motion planner is a good fit for LinuxCNC, and the error reporting (overcurrent, steploss, overheating, etc.) is excellent. There is even a 80V/10A big brother available as powerSTEP01. For a 3D printer I will implement the fan control and heaters using one of those cheap ($2,50) STM32F103 boards connected to the host using USB/custom HID device. Doing it that way prevents me from becoming locked to one specific board or platform. I used USB before together with LiunxCNC ont he Pi, even for motion control, and it works fine: https://www.youtube.com/watch?v=5WsugS7hTLk Now, I am stil interested in MachineKit and I still don't know what the advantages/disadvantages would be. Machineface would be a nice feature. If I have a system running Raspbian Jessie with PREEMPT-RT kernel, what would be the easiest way to set up MK? Can I also do a RIP build and run both LinuxCNC and MK next to each other? -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. Visit this group at https://groups.google.com/group/machinekit. For more options, visit https://groups.google.com/d/optout.
