i need to confirm something: in velocity mode, instead of G1x100, the command is G1X100 F200 ? (F for speed)
pengui1: I am not sure that question makes sense.
how is the sintaxis in velocity mode?
You are talking about a velocity-mode stepgen?
Then it will create pulses at a rate determined by the signal sent to its velocity pin.
so, i can specify the speed once
So, if the velocity pin is wired in HAL to X-position then G1 X10 will cause it to ramp to 10 units per second velocity, and stay there. But that would be rather unusual.
so, X10 means velocity=10 ?
No, it means that axis.1.position-cmd moves to 10 at the set speed.
(actually, even that is not necessarily true, because of coordinate offsets).
and because of acceleration/deceleration and distance not being enough it never reaches the set speed?
What pin do you have wired to the stepgen velocity input?
(I do rather think this is a #emc rather than #emc-devel duscussion, by the way)
i like do something like: net x-velocity => stepgen.0.velocity-cmd
loadrt stepgen step_type=0,0 ctrl_type=v,v
In that command, x-velocity is just a random signal name, it doesn't do anything.
lets back up a bit. What are you actually trying to do?
yes, i mean i in velocity mode
i need constant speed
so, i need to confirm the syntax in velocity mode
Ah, that again. Did you ever try M67?
from X100 to X200: G01X100 F500, G1X200F500
m67 is for digital output
yes... i will need that later... first i need to solve the constant speed
Your problem is (IIRC) that you were using spindle speed changes, and that was breaking the motion queue?
i think my "delay" problem is the acceleration/deacceleration in each position
this can be solved in velocity mode
Did you try making very small Z moves to drive the intensity? (They have to be small, or you get cosine changes in X)
yes, i try
Very, very small Z moves?
(works, but the delays remain)
Z=0.0001 and Z=0
That seems very odd.
i only want to confirm the sintax....
in velocity mode
There isn't a syntax
There is no "velocity" mode.
You can use velocity-mode stepgens, but that isn't the same as there being a "velocity mode" in G-Code
i know velocity mode is in stepgen
but the speed is set up with F command'
Yes. But that is totally separate from the stepgen velocity.
what do you mean'
(How to describe something I barely understand myself)
The G-code interpreter produces a list of motion commands. These eventually appear on a set of HAL pins listed here: http://www.linuxcnc.org/docview/html//man/man9/axis.9.html
Then in the HAL file those pins are linked to a freely-chosen set of HAL components such as stepgens to do whatever you want to do.
Typically you wire axis.0.joint-pos-cmd to stepgen.0.pos-cmd. But you don't have to.
in this case it will be something like: axis.0.joint-vel-cmd to stepgen.0.vel-cmd
With a servo system you wire the position-cmd output to a PID controller input, and that outputs a signal propertional to the position error. You can wire that to a stepgen velocity pin, and that makes sense.
There is an axis.N.joint-vel-cmd pin, but I don't know if it will do what you want.
(It's mainly for looking at in Halscope, to see what the axis is doing)
But there is nothing to stop you trying it.
yes... i'm searching sample hal programs
there is a few examples in velocity mode
net x-vel axis.0.joint-vel-cmd => stepgen.0.vel-cmd
You will find that they almost certainly get the velocity out of a PID controller block that compares commanded position to the encoder position.
in the emc-users people know this things?
or is people that say "i bought a machine i don't know how install emc" ?
no, this is the sort of discussion we get on emc. emc-devel is more for discussing exactly how to code new features or to fix bugs.
ok... i will go to the other channel
If you end up writing a component to look at current position and modulate laser power to suit, then that is new code, and here is the place.
(well, that's may asessment of the split, I am open to be corrected)
i'm doing something new... rastering is unknow here
Yes, but you are trying to do something new with existing software components. If and when you write new components, here is the place.
EMC: 03jepler 07v2.4_branch * r89354bb9a045 10/ (VERSION debian/changelog): release 2.4.1
EMC: 03jepler 07v2.4_branch * rba0ccfb684cc 10/docs/src/drivers/pluto_p.lyx: fix lyx markup broken in 416b833
jepler has changed the topic to: EMC2 development -- http://linuxcnc.org/
| Latest release: EMC 2.4.1
cradek: you used nurbs on a cnc before, no? how well do they work right now?
Cool .. 2.4.1 is out! Nice job guys!