what does mach output?

[Nick_Black]

i got some answers from my last post, but still have more questions... (sorry...)

lets say I only have 1 axis for siplicity sake (X axis we'll say) and it's hooked up to pins 2 for both direction and steps, also pin 10 for data input so mach knows how many steps have been taken in actuality.

lets say the're 32 steps pr revolution, and 1 rev = 1 mm (unit)

and here is the motor tuneing:

32steps 3000velocity 21 accel 5us steppulse 2dir pulse

ok, here are the actual questions :

1) to move the motor 'forward' one revolution:
output: 5usec (on) ??usec (off) looped 32 times. (on pin2)
correct? wrong? kinda?

2) to move the motor backwards would it:
output once(on) for 2usec then continue like the forward pulses?
or would it do 2usec(on), ??usec(off) looped till amount of steps desired.
first one right? second one right? none of them right?


3) data being sent to mach, is it:
a) when pin10 is on it counts one pulse till it's off.
b) distinguish direction between 5 usec to move cw, and a 2usec pule = ccw?
c) something else?



p.s. question #2 was sorta answerd in a previus post, but reading the manual i 'think' the answer i got from the thread and the manual contradict each other... so i just want confirmination...

cheers!

Nick_B

[ger21]

Originally Posted by Nick_Black i got some answers from my last post, but still have more questions... (sorry...) lets say I only have 1 axis for siplicity sake (X axis we'll say) and it's hooked up to pins 2 for both direction and steps, also pin 10 for data input so mach knows how many steps have been taken in actuality.

Mach can't count steps on an input pin. It can read data from an encoder and display it on the screen, but it can't do anything with it.

lets say the're 32 steps pr revolution, and 1 rev = 1 mm (unit) and here is the motor tuneing: 32steps 3000velocity 21 accel 5us steppulse 2dir pulse ok, here are the actual questions : 1) to move the motor 'forward' one revolution: output: 5usec (on) ??usec (off) looped 32 times. (on pin2) correct? wrong? kinda?

Command a 1mm move with a G0 or G1. Depending on the feedrate, Mach has to accelerate, possibly move at the feedrate (if it can be reached in that short of a distance), then decelerate. Pulses are spaced accordingly to accommodate the accel and decel. They will most likely all be spaced differently. It's far more complicated than you're thinking, I think.

2) to move the motor backwards would it: output once(on) for 2usec then continue like the forward pulses? or would it do 2usec(on), ??usec(off) looped till amount of steps desired. first one right? second one right? none of them right?

Exact same thing as the other direction, with the direction pin the opposite. The direction pin puts out a constant 5V in one direction, and 0V in the other direction. The direction pulse width only comes into play during rapid direction changes

3) data being sent to mach, is it: a) when pin10 is on it counts one pulse till it's off. b) distinguish direction between 5 usec to move cw, and a 2usec pule = ccw? c) something else?

None of the above. It can't do it.

[Nick_Black]

1: unfortunate, but at least that way i can see if it missed steps (or added them)

2: yes, the distance between pulses i assumed to be variable depending on the speed. but also, yes i agree it is probably more complex then i think, hence why I'm trying to figure it out
btw, now I'm starting to think mach assumes the motor controller fills up missed steps in case drilling into the object being molded slows down the accel rate?

3:there is no way to control the servo in both directions on one pin? (there for making it impossible to a 5 or 6 axis with one port?)

4: unfortunate, but ok

Edit: can mach 3 use pins 1, 14, 16, 17 ?

thanks for all your help so far if you could explain it in total a bit better that would be much appreciated XD i keep designing circuits and then figuring out i need to change them because of limitations of mach.... (and I want to get it right before i start building)

thanks again XD

[ger21]

Originally Posted by Nick_Black btw, now I'm starting to think mach assumes the motor controller fills up missed steps in case drilling into the object being molded slows down the accel rate?

Mach send out the exact steps it needs to move to where it's commanded to move. That's all it does. It makes no assumptions, and has no idea what the drive is doing. It has no idea if the motor stalls or misses steps.

3:there is no way to control the servo in both directions on one pin? (there for making it impossible to a 5 or 6 axis with one port?)

One step pin and one direction pin per axis. There are 12 output pins per port, so you may be able to drive 6 motors, but I'm not positive.

If you could explain it in total a bit better that would be much appreciated XD i keep designing circuits and then figuring out i need to change them because of limitations of mach.... (and I want to get it right before i start building)

What exactly are you doing? Designing a drive?

[Nick_Black]

Originally Posted by ger21 What exactly are you doing? Designing a drive?

yes, in essence

btw, i think you missed my edit (but kinda answerd it also..)
can mach 3 use pins 1, 14, 16, 17 ?

(since you said 12 output pins, i assume that is a yes)

and thank you sooooo much for putting up with me XD

[ger21]

I believe so, but I'm not positive.