How do I wire my omron encoder to my 9411 module.

[Tommyl]

I have an omron encoder and I want to connect to my NI-9411 module. The encoder wires are as follows:

Brown +VDC

Blue 0VCD

Black - A Phase

White - B Phase

Orange - Z Phase

I connect to the 9411 module as per the instruction manual. 

Pin 1 - A Phase (Black)

Pin 2 - B Phase (White)

Pin 3 - Z Phase (Orange)

Pin 4 - +VDC (Brown)

Pin 12 - 0 VDC

In addition, I give an extra power supply of 24VDC to the external power supply plug on 0 and 1.

I use a DAQ assistant to get the signal in LaView, but there are very strange readings when I test the devise. When I turn the encoder, in certain positions the counting suddenly goes haywire and counts up thousands of pulses in a few seconds. In addition, the encoder doesn't recognize the direction of rotation and increases the value in both directions. Please help.

[KateB]

I've an experience with lousy encoder reading.

In most case, connecting a +5V from 9411 supply it to an encoder will solve the problem.

Have you tried it?

[Tommyl]

I'm already giving +24VDC. Are you suggesting that I change the voltage supply to the 9411 module?

[KateB]

That's not what I mean.

See how to connect +5V on page 13 of http://www.ni.com/pdf/manuals/373506e.pdf

This is what I'm talking about.

[Tommyl]

This is the wiring pattern that I followed to set up, but it doesn't work properly. Testing in the Labview DAQ Assistant give very strange results. 1. The counter will only increase, so it's not recognizing the position. 2. If you turn the encoder just a little bit, the counter like gets stuck and even though you don't move the encoder the counter increases by thousands of pulses. So even though the encoder isn't moving, the DAQ Assistant thinks the encoder is moving at an incredible speed.

[KateB]

I assume that you use cDAQ 9172, and install 9411 on either slot 5 and 6, and configure to acquire encoder data from ctr0.

If you see inside DAQ Assistant, you'll find that it tell you which PFI connect to which phase.

Then, go to Start>>All Programs>>National Instruments>>NI-DAQ>>NI-DAQmx Help, and search 9411.

You'll find 9411 pin out, and realize which pin belong to which PFI.

Then, correct your wiring, and everything should work fine.

[Tommyl]

Thanks for the info to find the help page. Unfortunately, I had already been advised by the telephone help desk to reverse the pins 2 & 3. For the information of National Instruments, the wiring information supplied with the 9411 is wrong. The correct wiring as per the help page is:

Pin 1 - A Phase  =  PFI0

Pin 2 - Z Phase  =  PFI1

Pin 3 - C Phase  =  PFI2

Also unfortunately, this has not solved the problem. As the encoder is slowly turned, in certain positions the pulse value goes through the roof. It almost seems like this occures between increments. When turned counter clock wise, you can see that the value decreases slightly, but then the same fault occures and the value greatly increases. I have some spare encoder, but they all react in the same manner, so I don't think it is a faulty encoder.

[Tommyl]

Sorry, That was

Pin 3 - B Phase  =  PFI2

[Tommyl · Accepted solution]

The telephone help desk of NI Singapore suggested that I use pull-up resistors. I used three 1k Ohm resistors wired between the following pins.

Pin 1  -  1k Ohm  -  Pin 4

Pin 2  -  1k Ohm  -  Pin 4

Pin 3  -  1k Ohm  -  Pin 4

As pin 4 is the +VDC and the pin 1 - 3 are the phase it must be increasing the signal some how. All I know is it seems to work. I'm Happy

[Gravy_Train]

It would be nice if NI would update their documentation for the 9411.  I just wasted 8 hours trying to figure out how to hook a quadrature encoder up to this card based off of their current documentation on line with completely negative results.  I hooked up different encoders with different output drives (PNP vs NPN) thinking it was a problem with the device or device wiring.  Now to simply find out on a discussion forum post that is a year and a half old that the B phase and Z phase need to be switched and NI has not changed their documentation is upsetting at best, down right negligent on NI's part at worst.