Re: [CAD_CAM_EDM_DRO] Re: Step Motors with Feedback From Sargon DRO ?

reed_irion wrote:

>These are indeed glass scales. I think this type of encoder is very
>common as Sargon is "the" cheap encoder brand. According to the
>manual, the outputs are quadrature. Each axis only has five lines so
>I could use the silly scope to figure out what is what. I was
>thinking all I have to do is put a breakout connector before it goes
>into the digital readout. Maybe throw in some TTL buffers just for
>laughs. So do I just plug the encoder signal back into the EMC ?
>

No. EMC has no provisions to read the quadrature signals directly. They
come in pretty fast for software to be trused to count them without ever
missing a pulse. So, you need some hardware to read the quadrature
signals and convert to a position count. The Dan Mauch/Tom Kulaga
DRO board is probably the lowest cost solution to this. There are other
encoder cards, too. I sell a somewhat more expensive board that connects
to the parallel port, and contains 4 encoder counters, 4 step rate
generators
and digital input for limit and home switches and output for spindle,
coolant, etc.

>How do I tell EMC that I am using a stepper motor instead of a servo
>motor ? Or does it not matter since I am using freqmod ?
>
>

Freqmod is open-loop, only. If you use the Mauch/Kulaga DRO board, you'd
use smdromod.o instead of freqmod.o

Jon