On 9 September 2013 13:28, Rudy du Preez <r...@asmsa.co.za> wrote: > The encoders have differential A and B pulse trains, but > the A channel is used in the beginning to send 8 bytes of serial data plus > some incremental pulses to establish the absolute positions of the axes when > activating the robot after a start-up. The 8 bytes give "P(+ or -)XXXXX(CR)" > with M=XXXXX the number of full turns of the motor from the home position. > The next incremental pulses (Po) give the number of counts of a partial > turn.
As it is all on channel A then the Mesa encoder counter won't see the serial data as counts, which is good. I think that the encoder channels pass-through to the FPGA card, so are visible as GPIO. It is possible to run a base-thread with a Mesa system and bit-bang the GPIO in that thread. So, it seems plausible to run a 50.2 uS base-thread and sample the A-channel in a component. It might also be possible to add a UART to the bitfile that shares the A channel hardware pin with the encoder counter, though this would probably also need a custom component to manage it. Step 1 is probably to create a base thread and run Halscope in it while sampling the A-channel. If you can see the serial data then the chances are good that it can be made to work. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto ------------------------------------------------------------------------------ Learn the latest--Visual Studio 2012, SharePoint 2013, SQL 2012, more! Discover the easy way to master current and previous Microsoft technologies and advance your career. Get an incredible 1,500+ hours of step-by-step tutorial videos with LearnDevNow. Subscribe today and save! http://pubads.g.doubleclick.net/gampad/clk?id=58041391&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
