On Tue, 10 Sep 2013, Rudy du Preez wrote: > Date: Tue, 10 Sep 2013 19:50:53 +0200 > From: Rudy du Preez <r...@asmsa.co.za> > Reply-To: "Enhanced Machine Controller (EMC)" > <emc-users@lists.sourceforge.net> > To: emc-users@lists.sourceforge.net > Subject: Re: [Emc-users] Motorman Robot with absolute Yaskawa encoders > > I now realize that the A phase cannot go through the counter in the firmware > of the 6i25+7i77 setup and then read serial data.
Well... Thats not entirely true, the muxed data serial can be recovered just like the muxed encoder data is. 9600 baud is so slow that the muliplexing will cause minimal distortion (it will be sampled at 4 MHz so something like 400 samples/bit time) So _it is_ possible to have a dual use pin, though its a fair hack to the firmware (adding the multifunction UARX/Counter pin and arranging it to get wired correctly) and HM2 driver (supporting that new pin type) If you had free differential input pins (7I74 on P2 etc) it might make more sense to simply connect the A/'A pins to the second differential input that connects to a UART. Other options are using the PC's serial or USB/serial with 422 adapters since the absolute position is only read once and need not be read real time > > Would it be easier to use a 5i20 + 7i33 combination. Then modify the > firmware so under some control input bit the A phase is first passed through > by-passing the counter, so that bit-banging can be done for the first 8 > bytes to get the absolute offset. > > Another way suggested by Marius is to use a differential multiplexer on the > encoder line before it gets to the 7i77, then first pass the A phase to a > gpio input and then switch to the encoder input. > > Any more ideas? > > Rudy > > > ------------------------------------------------------------------------------ > How ServiceNow helps IT people transform IT departments: > 1. Consolidate legacy IT systems to a single system of record for IT > 2. Standardize and globalize service processes across IT > 3. Implement zero-touch automation to replace manual, redundant tasks > http://pubads.g.doubleclick.net/gampad/clk?id=51271111&iu=/4140/ostg.clktrk > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > 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. ------------------------------------------------------------------------------ How ServiceNow helps IT people transform IT departments: 1. Consolidate legacy IT systems to a single system of record for IT 2. Standardize and globalize service processes across IT 3. Implement zero-touch automation to replace manual, redundant tasks http://pubads.g.doubleclick.net/gampad/clk?id=51271111&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
