5I56 + 7i76 Lathe

I'm probably just missing something simple, but after looking for the last couple days I can't seem to find any reference to this problem. I also have few other issues but it seems easier to to tackle one at a time. My first issue is when I setup the spindle using the analog output pins of my 7i76 card it works perfectly in the forward direction but when you run the spindle in reverse the S commands are backwards aka out of a 2000 rpm spindle speed S500 in the forward direction runs 500 rpms but in reverse it runs 1500 rpms. This setup is on gang tool lathe using servos and hitachi vfd.

-michael

You need an absolute value function between the spindle command and the spindle out.
also the spindle minlimit should be 0 and the maxlimit should be RPM at 10V

Can you give me a couple of examples, with a MINLIMIT set to 0, M4 doesn't do anyting for me.

Thats a good thing! M4 should not have done anything because you are handing
a negative number to a unsigned variable.
(That this does anything other than output 0V is a bug in the Hostmot2 driver)

I would change:

loadrt abs names=abs.spindle
to
loadrt abs names=abs.spindle,abs.spindle_cmd

and add this line:

addf abs.spindle_cmd servo-thread

and then change

net spindle-vel-cmd <= motion.spindle-speed-out
to
net spindle-vel-cmd abs.spindle_cmd.in <= motion.spindle-speed-out

and finally change

net spindle-vel-cmd => hm2_5i25.0.7i76.0.0.spinout
to
net abs.spindle_cmd.out => hm2_5i25.0.7i76.0.0.spinout

Wish I was bit more knowledgeable on this I hate taking up folks time. This is error message with my hal file attached.

Debug file information:
Can not find -sec MOT -var MOT -num 1
Can not find -sec IO -var IO -num 1
Can not find -sec LINUXCNC -var NML_FILE -num 1
Can not find -sec EMC -var NML_FILE -num 1
Sweet_Mesa.hal:130: Signal name 'abs.spindle_cmd.out' must not be the same as a pin. Did you omit the signal name?
23162
PID TTY STAT TIME COMMAND
Stopping realtime threads
Unloading hal components

Sorry
net abs.spindle_cmd.out => hm2_5i25.0.7i76.0.0.spinout
should be more like
net abs-spindle-vel-cmd hm2_5i25.0.7i76.0.0.spinout <= abs.spindle_cmd.out

Now onto the problem with the spindle encoder not working, which might be hardware.

Think you could supply a bit more information on that, it does seem to be the index and not the rpm section of the encoder. Both I've check back at the input of the 7i76 with a scope and seem to be clean and working.

-Michael

can you give details of the encoder your using and connections used