[HeyLaughingBoy]

Yes, I wish it also had differential inputs.

My original design was based on an Arduino Nano with an AtMega328. Originally it was designed to read 0-10-0V position signals. This is from really old machine tools :-)

Processing encoder inputs was a much later change. With the rate of interrupts coming in from a high-resolution encoder turning at 3,000 RPM, there was no way it would keep up and still do all the processing needed.

The product volume wasn't high enough to make it worthwhile moving to a processor that had the timer/counter resources to handle it in hardware, so the simplest solution was adding a $6 chip (and a $2 differential interface chip to handle the differential encoder output channels).