RE: Freqmod.o

["Brad Nowak" <neatguy-at-telus.net>]

-----Original Message-----
From: emc-at-nist.gov [emc-at-nist.gov]On Behalf Of Jon Elson
Sent: February 10, 2003 9:42 AM
To: Multiple recipients of list
Subject: Re: Freqmod.o





Brad Nowak wrote:

> Hmmm .. I read the linuxcnc.org handbook and it says about
> freqmod. "Phase stepping requires the computer to output the motor
> phase signals directly, the stepper driver is just an amplifier.".
>
> I was planning to use a L298 dual H-bridge to drive my motors.
>
>  A bipolar stepper motor would require two outputs for each of the two
> coils in the motor. The steppermod module only has step and
> direction. Am I misinterpreting something ?
>
The full step drive waveform really only needs 2 wires per motor.  For
each motor coil, current is
either going one way or the other.  For a half-step drive, the current
in a coil can also be off,
and that would require more wires.

Steppermod.o only produces step and direction, but freqmod.o can produce
step/dir OR
the 2-wire phase signals.

Jon

How do I make freqmod.o produce 2-wire phase signals ? It looks like
step/dir when I look at the state of the lines.

brad