differential linear glass scale output

[gotty101]

Hello hopefully someone smart will be able to point me in the right direction. Im looking read a linear glass scale with my arduino for a project im doing. Only problem is i have some glass scales that are single ended and some that are differential (eia422)

I would like to build a standard circuit that would allow me to connect either of these types to my arduino and read the quadrature signal of them. I guessed that i need a differential receiver like sn75175d but then if i put my signal through this im not sure if my single ended scales will work.

Ive been looking on the internet and saw that this person has managed it but looking at the pcb traces and the chip he has used it seems to be wired in a very strange way. The is he is using is a AM26LV321 which is a DIFFERENTIAL LINE DRIVER and from what i can see its wired like this (ive only drawn in one signal pair)

This is the website where i saw this method.
http://www.yuriystoys.com/2016/02/touchdro-quadrature-adapter-details.html


Can anyone explain how it works and even if my understanding of how he has managed it is correct?

Many Thanks

Trev

 

[luni]

You need a AM26C32 not a AM26C31 for converting a RS422 signal to single ended. However, you can simply use A and B signals (just ignore /A and /B). As long as your encoder doesn't sit close to large motors or other EM noise sources it will work just fine.

 

[gotty101]

Thanks guy, i got the scale linked up by a diff line receiver ic and all is good.

I was just intrigued how he managed to do it with that ic.

Thanks again

Trev