can I output square waves for step signal?

[mike944]

I have some old stepper drives that i am trying to retrofit to PC control, and i need square waves as a step pulse. the "on" and "off" time should be approximately equal. Can EMC do this?

As an alternate, pulsewidths of 50-100 microseconds seem to work acceptably, using TurboCNC, but i'd really like to use EMC2. I can't figure out how to adjust the pulsewidth.

The EMC2 documentation loosely says it turns the step pulse on when it needs to, and turns it back off during the next base period.

Obviously i can't run high speeds with this setup, but i don't need to either. The max speed my these drives and motors can support is about 2000hz

So, can i output square waves, or just longer pulses?

[Andre' B]

You could put a harware pulse stretcher in the circuit.

http://www.electronics-lab.com/artic.../555basics.htm

[mike944]

That's currently the direction i'm heading, however I was trying to avoid that.....i'm only mediocre with electronics. Doing it with software would make my interface less complicated, and given my own history with electronics, more likely to actually work......

[tfmacz]

because you have a very slow speed limit, "The max speed my these drives and motors can support is about 2000hz" would you not just set the base period to something real slow? If you turn off the "pulse doubler", it is new and I am not sure where to do this, maybe just don't turn it on????, then the step pulses are turned on in one period and turned off in the next.

[keebler303]

you have a PM



Matt

[samco]

if you look under parameters here http://linuxcnc.org/docs/2.2/html/ma...stepgen.9.html

you will see there is steplen and stepspace... I think this is what you want to use to do what you want.

This is a step and direction drive - correct? (not quadrature?)

sam