Help with closing the Loop 7i96 + 7i85s

Hello guys,

I´m pretty much a noob when it comes to LinuxCNC and the Mesa stuff.

I have the 7i96 and 7i85s cards up and running so far. I sorted some wiring issues that prevented me
to control the axis manually.

Now my idea would be to close the loop via LinuxCNC.

I got the HSC86A Hybrid Servo Drives and NEMA34 12NM Closed Loop Stepper with an 1000 p/rev encoder on them.

If I disconnect the Encoder input on the Drive the drive automatically goes into fault mode which makes sense.

But how can I wire up the encoder to the 7i85s and make LinuxCNC close the loop for me?

Is it possible to splice the wires from the Drive and connect them to the 7i85?
Or do I need to connect the encoder directly to the 7i85s and designate output pins which send the encoder signal back
to the drives?

I´m pretty much lost on this topic.

Would be great if someone could help me with this.

Greetings Mike

You don't use the motor encoder to "close the loop" in linuxcnc. You'd use a second, linear encoder to get the actual position. Theres little point in doing it that way.

I want to use the encoder on the motor. I don´t want to use or install linear encoders.
The encoder on the motor would give me a resolution of 0.005mm with my 5mm pitch ballscrew. The motor is solidly coupled with the ballscrew.

So why should I install an extra linear encoder?!

Thank you very much. That´s what I wanted to hear. Thanks aswell for the tip with the wiring ^^

I use a signal conditioner to split the encoders to the drives and the 7i85. I have used these on two different machines. One running MachDrives BRC’s and the other  Gecko 320’s. No issues and great performance. 

I daisy chain to the drives off the input side and run the output to the 7i85.

Automation Direct - fc-iso-d