Using NI 9205 or NI 9403 DIO module for encoder measurement

[RdhSaini]

Hello,

Is it possible to measure angular position by counting pulses from a quadrature encoder using NI DIO 9403 or NI 9205 modules coupled with cDAQ 9174. I do not have access to other modules which have inbuilt counters. If possible, can someone please guide me on how to do that?

[SteveD123]

What resolution do you need?

What device are you using?

I suggest you search for a "Quadrature Decoder Circuit" and couple that up to a suitable up/down counter with reset. An example is the 74HCT193; cascade as many of these 4 bit blocks as you need to get the number of bits you require. You can reset on the z input, from some limit switches or from a digital output from your 9403. The parallel lines from your counter go into digital inputs on the 9403.

Oh look someone has done it all for you here: http://mumris.eu/Decoder.htm .

[RdhSaini]

Thank you so much @SteveD123.

I have tried counting the pulses using LabView but there was a huge lag. So, I have coupled with an Arduino and used interrupt program to count the pulses. Later, I have coupled it with a serial input program to access the counter value.

It worked fine for me.