Full understanding of the quadrature encoder?

[busarider29]

We have a new machine build scheduled for next year that will use a spindle motor. That motor may have a quadrature encoder mounted directly on the spindle shaft (not motor shaft). I have a colleague that wants to split the compliments and use two for feedback to the machine and the other two for connecting to his NI hardware for one-off testing. Won't doing this affect accuracy of our spindle speed feedback if not using all four of the compliments for feedback to the machine?

Thanks,
D

 

[mk42]

Besides whatever potential electrical effects due to voltage differences between the two systems, it will do two things:

1) Each side will have half the resolution. You could potentially work around this by using an encoder with double the desired resolution, if one is available.
2) You won't be able to tell what direction the spindle is turning. This might not be a problem for you.

 

[widelto]

Why don't you use an encoder splitter like this:
http://encoder.com/repeater-converter-splitter/
This is isolated and you will have no problem at all.

Other brands also sell products like this.

 

[busarider29]

Why don't you use an encoder splitter like this:
http://encoder.com/repeater-converter-splitter/
This is isolated and you will have no problem at all.

Other brands also sell products like this.

Because my colleague for some reason, likes doing things the cobbled way, instead of the right way.

Thanks for the link.

 

[AGill]

split the compliments

This is doable if you don't need to know the direction from the encoder, and you mean A & A' as one compliment and B & B' as the other, and this application doesn't require the resolution of both channels.
I've seen many times where a quadrature encoder is installed but only channel is required/used.

 

[Peter Nachtwey]

If one of the encoder inputs can be put into high impedance mode then you can daisy chain the encoder into 2 inputs. The last one needs to have the normal termination.