Terry wrote:
> I got it to work with the scale of .00222 per Jon Elsen
> My lack of output was because I didnt turn on the m5i20-dac-enable
> Now I have +10VDCwith s5000m3 and -10VDC with s5000m4
> Most VFDs take +10 only --How can I get the voltage to only go positive?
Assuming that some digital output bit(s) tell the VFD whether to 
run forward or reverse, then you'd need an absolute value 
function (hal has the abs component) to make the value always 
positive.  You'd need to loadrt the abs component, I think the 
hal syntax would be :

loadrt abs count=1

Then insert it into the servo-thread (I think) with an addf 
command, like this:

addf abs.0 servo-thread

and then route your spindle speed command through it.  it looks 
like this with my UPC boards :

# set scale for 5000 RPM MAX and connect spindle speed to USC DAC
setp ppmc.0.DAC8.00.scale 500.0
newsig spinspeed float
linksp spinspeed <= motion.spindle-speed-out
linkps abs.0.in => spinspeed

newsig absspin float
linksp absspin <= abs.o.out
linksp absspin => ppmc.0.DAC8.00.value

It likely would be a bit different for the Mesa board's DAC.

Jon

-------------------------------------------------------------------------
Sponsored by: SourceForge.net Community Choice Awards: VOTE NOW!
Studies have shown that voting for your favorite open source project,
along with a healthy diet, reduces your potential for chronic lameness
and boredom. Vote Now at http://www.sourceforge.net/community/cca08
_______________________________________________
Emc-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/emc-users

Reply via email to