On Thu, 20 Aug 2009, Eric H. Johnson wrote: > Date: Thu, 20 Aug 2009 14:46:51 -0400 > From: Eric H. Johnson <[email protected]> > Reply-To: "Enhanced Machine Controller (EMC)" > <[email protected]> > To: "'Enhanced Machine Controller (EMC)'" <[email protected]> > Subject: [Emc-users] Hostmot firmware question > > Hi all, > > When the firmware for any of the hostmot supported Mesa boards is loaded on > running EMC, does it zero the encoder values? IOW, if I run EMC, then shut > it down but leave the computer running, then manually move the axes, when > EMC is restarted, what values will the firmware be holding for the encoder > positions? Will it have counted the manual motion and retain that after EMC > restarts? > > Thanks, > Eric > > Loading the firmware will clear the encoder counts (the register values will be loaded from the bitfile = 0), If you dont reload the firmware, the hardware count will be correct, but since its only a 16 bit counter and could have wrapped without the driver noticing, actual count read by the driver could be wrong.
The driver may also clear the counter as part of its startup, no sure about that. If you wanted to maintain position info across EMS starts, a 24- 32 bit counter would probably be needed. The 16 bit counter was used so that that the timestamp and encoder count are read simultaneously in one 32 b it read operation. > > > ------------------------------------------------------------------------------ > Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day > trial. Simplify your report design, integration and deployment - and focus on > what you do best, core application coding. Discover what's new with > Crystal Reports now. http://p.sf.net/sfu/bobj-july > _______________________________________________ > 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. ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
