On Fri, 17 Jul 2009, Leslie Newell wrote: > Date: Fri, 17 Jul 2009 22:13:46 +0100 > From: Leslie Newell <les.new...@fastmail.co.uk> > Reply-To: "Enhanced Machine Controller (EMC)" > <emc-users@lists.sourceforge.net> > To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> > Subject: Re: [Emc-users] Hostmot2 homing > > Hi Peter, > > Each output swings from 0.48V to 4.1V. When IDX is high, /IDX is low. > Therefore the voltage between them is about 3.6V. > > Les >
Well if the extra filtering of the TTL inputs helps, I would do the trick with raw-write to setup the filter time constant (the QFilterRate register at 0x3400). Currently the filter frequency is 33 MHZ which gives a 450 ns time constant: good for encoder count rates up to ~4 MHz, if the filter was set to divide by 8 (loaded with 6) you could still count up to 500 KHz but reject pulses up to 4 uSec long. You can divide the 33 MHz by up to 2049 (which _will_ be too slow, limiting your count rate to ~2KHz (filter on) or 10KHz (filter off) > >> What I was asking about (maybe not very well) is differential drive: in other >> words measured between IDX and /IDX. This should be positive in one index >> state and negative in the other. > > > ------------------------------------------------------------------------------ > Enter the BlackBerry Developer Challenge > This is your chance to win up to $100,000 in prizes! For a limited time, > vendors submitting new applications to BlackBerry App World(TM) will have > the opportunity to enter the BlackBerry Developer Challenge. See full prize > details at: http://p.sf.net/sfu/Challenge > _______________________________________________ > 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. ------------------------------------------------------------------------------ Enter the BlackBerry Developer Challenge This is your chance to win up to $100,000 in prizes! For a limited time, vendors submitting new applications to BlackBerry App World(TM) will have the opportunity to enter the BlackBerry Developer Challenge. See full prize details at: http://p.sf.net/sfu/Challenge _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
