Mostly, I was hoping to avoid the thread delays of having to go through hal adding 1-2 more thread cycles to the "staleness" of the data. (Encoder read/process to velocity, Hal read from Mesa, Hal process value/scale, Hal write back to Mesa), and was just curious if it had been tried before.
Todd Zuercher P. Graham Dunn Inc. 630 Henry Street Dalton, Ohio 44618 Phone: (330)828-2105ext. 2031 -----Original Message----- From: Peter C. Wallace <[email protected]> Sent: Monday, December 07, 2020 1:08 PM To: Enhanced Machine Controller (EMC) <[email protected]> Subject: Re: [Emc-users] Mesa Tacho Generator? [EXTERNAL EMAIL] Be sure links are safe. On Mon, 7 Dec 2020, Todd Zuercher wrote: > Date: Mon, 7 Dec 2020 14:47:56 +0000 > From: Todd Zuercher <[email protected]> > Reply-To: "Enhanced Machine Controller (EMC)" > <[email protected]> > To: "Enhanced Machine Controller (EMC)" > <[email protected]> > Subject: [Emc-users] Mesa Tacho Generator? > > Is it possible to set up a firmware for a Mesa FPGA that could read > the encoder velocity from an encoder input and output that velocity as > an analog command directly to an analog output (hopefully at faster > than the servo thread rate) in order to bypass having to do that > connection in Hal? Can the analog outputs of any of Mesa's daughter > cards be updated faster than the Servo-thread rate? Its possible but a fair amount of work, I would try servo thread operation first (4KHz or so servo thread operation is possible with a decent CPU and PCI/PCIE cards) There are a number of people that have done this with decent results Note that the encoder velocity estimation uses delta_count/delta_time calculations where delta_time is the time between counts (_Not_ the sample time) so the quantization noise is much lower than the +-1 count you would have with a delta_count/sample_time velocity calculation. > > Todd Zuercher > P. Graham Dunn Inc.<http://www.pgrahamdunn.com/index.php> > 630 Henry Street > Dalton, Ohio 44618 > Phone: (330)828-2105ext. 2031 > > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
