Jeff, Thanks for the explanation. Follow up question on using an axis for this (A for example). What is the minimum setup I need to map the 'A' parameter from the g-code to a dac. It doesn't have an encoder, doesn't need a pid, and the dac output should just be the value of 'A' multiplied by some scale (0.0 = duty cycle of 0%, 100.0 = duty cycle of 100% for example, and regardless of whether in is in mm or inches). What does the kinematics and trajectory planner need for anticipating the time for this axis to move, given that it can move to any point basically in zero time.
In the ini file, can I just set axes = 4 coordinates = X Y Z A (And boiler plate for the Axis 3 parameters, except make axis type rotary so that the value is in "degrees" and hence won't change when going from mm to inches) Then mostly in core-servo, something like: newsig Aoutput linksp Aoutput <= axis.3.motor-pos-cmd linksp Aoutput => scale.0.in linkpp scale.0.out => m5i20.0.dac-00-value Regards, Eric > When an S-word is encountered, emc first waits for any > pending move to finish, then modifies the > spindle-speed-output, then begins the next > move. This causes not only an "exact stop", but an additional pause > that appears to be around 100ms on my test machine. This is > not intended to allow the spindle to reach the commanded > speed, it's true of almost anything that isn't a motion, but > must happen at the right time with respect to motion. > > I ran the following program on the simulator: > M3S100F10 > G0X0 > G1X.1S100 > G1X.2S200 > G1X.3S300 > G1X.4S400 > M2 > Here's a plot of spindle speed (bottom plot) and X velocity > (top plot) as the program runs: > http://emergent.unpy.net/files/sandbox/spindle-pauses.png > you can see the 3 pauses in X axis motion, one for each > spindle speed change. > > It's clear that improved handling of motion and non-motion > actions is important, but work on this will have to wait > until we start the development for what will be emc 2.2. > > If you hook the laser intensity to the Z or A axis (instead > of to the spindle speed), and set the acceleration and > velocity for that axis to very large values, maybe you will > get better results because this synchronization between each > move will go away. ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
