>From the "CNC Programming Handbook" by Peter Smid (ISBN 0-8311-3158-6) and basically describing Fanuc behavior....
G28 is NOT modal, the G28 must appear in each block where used G28 in a block by itself is not valid, one or more axis parameters must be supplied. Only those axes specified will move. Traverse rate will be rapid, like in a G00. The axis parameter must have a value specified (Fanuc behavior). The value will obey the absolute or incremental mode currently in effect!!! The value is used as an intermediate way point on the path to machine zero. If no intermediate way point is desired, the value should be such as to cause no motion away from the starting point. For example while in absolute mode the value should repeat the current position, or while in incremental mode the value should be zero. You MUST know what mode you are in before using a G28 command. The purpose of the intermediate way point is to avoid clamps etc. I do not know if some controls other than Fanuc will allow the value to be omitted and assume that no intermediate way point is desired, but this seems a reasonable behavior to me. Regards, Steve Stallings > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Chris Radek > Sent: Saturday, August 04, 2007 3:33 PM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] G28 return to home > > > > Hi Stuart, can you find for us a reference that explains how G28 > typically works on non-EMC controls? If they all work the same except > for EMC, we could talk about breaking with ngc for this. > > In particular I want to know how it should behave when > > in G90 mode and all axes are specified > in G90 mode and some axes are specified > in G91, all > in G91, some > > Also is there a difference of behavior when axes are specified to be 0 > and when they're nonzero? You said something about an intermediate > point/move that I didn't understand. > > Thanks > > Chris > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
