7i33 spindle

Hello.
I am setting up a lathe with 5i22 + 3 7i37, I have a doubt about the 0 - 10 volt analogue fanuc spindle drive.
I have a new 7i33 available, I would like to know if I can use only one spindle channel and leave the other 3 free.
A problem leaving -10 +10 volts output instead of 0 +10 only.
it can be done ?
regards
Mauro

Thanks Andy, but we are going to use 2 analogs one also for motorized tools in the future.
Without counting the convenience of the differential encoder input I have already connected and it works fine.
I could not get the analogue output but I think it's changing in pdm ..
If you have some example link I would be useful
regards
Mauro

Well, now the signal has a single polarity in both m3 and m4, 0 to 9.7 volts.
But i have gnd positive and analog out negative ...
I saw that abs has pins for the sign but I do not know how to do it.
regards
Mauro

There are a couple ways to invert the 7I33 output, probably the easiest is to just invert the
PWM scale parameter (change it to a negative number)

Hi pcw
The spindle works well, now I'm trying the orientation but I have some problem.
The spindle index enable signal is always red, but the spindle index becomes yellow for the time that the encoder index is high controlled with oscilloscope.
I certainly made confusion in setting the orient, but there are so many different examples, each one uses different methods ..

Now with orient mode 1 or 2 you enable cw or ccw relais, abs out ok but you really do not enable analog output.
I attach the section hal and pid setting at end
regards
Mauro

Thanks Andy
The functions are added to the servo thread.
Now the main problem is that in orient mode I do not have the spindle on active.
The "pid" are regularly switched abs out from the right output as well as the signs.
In fact the cw and ccw relays get excited well.
But the analog output is not enabled.
Tonight let me see the full configuration files, now I have to go around with the xt550

Here I am with the files.
There are "high" commented numbers, they are referring to my friend's 5i22.
I'm trying with a 5i23.
Thanks in advance
Mauro