Need help with the AM26LS32ACN

Using Arduino General Electronics
1

Hi, I'm new here
I am trying to convert the sub-outputs (A high, low, B high, low) of an encoder into standard Channel A and B quadrature encoder signals.
My encoder is a Maxon #225773. Maxon recommends the differential Line receiver AM26LS32.

So I am looking at this datasheet and actually did some ONE test already but my signals are not they should be.

Here's the datasheet for the line receiver: http://www.ti.com/lit/ds/symlink/am26ls32a.pdf

I am using 2 of the 4 comparators in the chip and I am just completely confused about setting up Pin 4 and Pin 12.

in page 2 of the PDF, there is a nice table that is supposed to help me setting them up but honestly it doesn't help me at all.

Could anyone point me in the right direction?

Here's what I tried. I didn't have the complete datasheet and there was mention to put Pin4 to Low (ground) and Pin12 to High (Vcc) in order to activate the high impendance output. That datasheet didn't have any other information and figured I'd try this mode which didn't work out, the output signal wasn't recognized by my controller.

Note that my controller is designed to read the output of an HEDS9100 which is an optical encoder with built in line receivers. My new encoder doesn't have these line receivers and I need to do internally before I send the output to the controller.

Based on this datasheet, and if I had to guess I would try and put Pin4 to High and would let Pin12 floating. But I am afraid of damaging my controller and I have no practical way to test that other than trial and error...

Basically any advice here would be really appreciated.

Thanks
Z.

2

zytrahus:
I am using 2 of the 4 comparators in the chip and I am just completely confused about setting up Pin 4 and Pin 12.

Either tie pin 4 to Vcc or tie pin 12 to Gnd or both. If 4 is low and 12 is high the outputs of the chip will be disabled.

3

Thanks :slight_smile: I finally was able to get my controller to read the signals.

I have one more question though. On the AM26LS32 datasheet, each comparator has a A and B input. Does it matter to which I am connecting my A+ and A- signals of my encoder?

To clarify, I am using one comparator for A+ and A- (A-high, A-low) and another comparator for B+ and B-.

I have no idea how these comparators work and I am wondering if the output of the comparator would be any different if I connect A+ (encoder signal) to 1A(comparator) and A-(encoder signal) to 1B(comparator).

thanks
Z.