Using 7i76 to control spindle reverse with Danfoss DC150 DC controller

I am getting ready to wire up the spindle control circuitry of the 7i76. I did the initial setup with pncconf and so far everything has just worked. My question is do I need to do anything special to insure the spindle has reached 0 rpm before allowing the relay to activate or is that all handled in the pncconf setup.

I dont think pncconf makes any provision to ensure the the spindle has stopped before
reversing.

Do you have a spindle encoder? If not you will probably have to use a timer and some logic to prevent the direction from changing while the spindle is still rotating.

Yes, I have a spindle encoder. It is homemade, 100 counts plus index. I used to just use Index plus A channel. I have just changed it over to use A, B and Z. I am getting a lot more variation in speed reported than when I used to run it as just index plus counter mode, so, I need to look at the outputs with halscope and see how they look. I may need to adjust the positions of the A and B detectors.
I think that I will hook up the spindle_ena switch and the spindle speed controls first and verify that they are working, before I hook up the direction relay.
Does the schematic look correct for the wiring?

Hi Alan,

I think you can program the Danfoss for speed up and speed down in second's. Usually 3 second's for up and 3 second's for down.
You can switch direction by linuxcnc imediatly. The Danfoss will do the rest.

Grotius,
I looked in the Graham Transmissions Cycletrol 150 manual (I understand that Danfoss sold the DC controller line to Graham Transmissions, Inc.). I didn't find any such programming options. However, I did find that the braking option is supposed to bring the motor to a stop within 1/4 second (when the braking switch is closed).
So, the question remains, with an encoder will linuxcnc/mesa try to change the state of the dir switch before it detects 0 rpm? Or does it look for 0 rpm before changing the state of the dir switch?
Alan

Any delay in changing the spindle direction must be specifically created
using components in the hal file, LinuxCNC will simply change the spindle
direction immediately on 'S' commands or when doing spindle synchronized moves like rigid tapping.

This will likely destroy your spindle motor drive, the relay, and possibly the spindle motor. You can get away with this with a VFD, since you can program the rampup/rampdown rates but not a relay reversing circuit which requires that the drive be totally off and motor stopped before reversing.

I would recommend that you test any hal control logic and relay operation thoroughly before connecting your spindle motor. Ideally someone with a similar reversing relay setup could provide a sample hal file since its fairly involved...