Re: [CAD_CAM_EDM_DRO] Digest Number 2461
Posted by
Ray Henry
on 2002-07-25 16:18:46 UTC
Terry
Just a quick note to add a couple thoughts to Jon's post.
Steppermod doesn't use the axis tuning variables but freqmod does. With
freqmod is is easily possible to build up pulses or position error in the
following error buffer. One of the best ways to build up following error
is to command very rapid acceleration to rapids as Jon indicates.
If the max velocity in any axis is set the same as the trajectory planner
max velocity then those built up pulses can not get put back into the
pulse train during a rapid move. I'd lower the acceleration and give a
little bit of headroom by making traj max_velocity a bit bigger than axis
max_velocity.
It is also possible with freqmod to command more pulses during a rapid
move than can be accomodated by freqmod using the period setting on your
PC.
HTH
Ray
Just a quick note to add a couple thoughts to Jon's post.
Steppermod doesn't use the axis tuning variables but freqmod does. With
freqmod is is easily possible to build up pulses or position error in the
following error buffer. One of the best ways to build up following error
is to command very rapid acceleration to rapids as Jon indicates.
If the max velocity in any axis is set the same as the trajectory planner
max velocity then those built up pulses can not get put back into the
pulse train during a rapid move. I'd lower the acceleration and give a
little bit of headroom by making traj max_velocity a bit bigger than axis
max_velocity.
It is also possible with freqmod to command more pulses during a rapid
move than can be accomodated by freqmod using the period setting on your
PC.
HTH
Ray
On Wednesday 24 July 2002 03:51 pm, you wrote:
> Message: 6
> Date: Wed, 24 Jul 2002 01:25:39 -0500
> From: Jon Elson <elson@...>
> Subject: Re: setting up EMC
>
> terrytwombly wrote:
> > OK What is a following error? and where do I go to change it?
>
> Following error is supposed to mean that a servo-controlled machine
> was too far from the commanded position. If the machine does not
> have encoder feedback, then it means that the parameters in the
> xxx.ini file were such that the SIMULATED servo-controlled
> machine had that condition. This is because steppermod.o and
> freqmod.o (when in open-loop mode) uses a software simulated
> servo machine to generate the step pulses. The most common
> problem is that DEFAULT_ACCELERATION and MAXIMUM_
> ACCELERATION are too high. In inch mode, 20.0 (the default)
> is a LOT of acceleration, that's 20 inches/sec/sec! Set it to 2.0 and
> try again.
>
> > and
> > what is minimilltasking.cc 962: error telling me and do I go to get
> > this infomation.
> > Again thank you all for this help. I do belive that if I stay with it
> > and you all do not get tired of me EMC shoul be running soon
>
> The on-line help should have the error codes in it. Is this an error
> code when it is running, or a compiler error when building EMC?
>
> Jon