Unable to read quadrature encoder with NI 9411 in NI Max

[jlduchar]

Hello all,

This is my first post here as I am new to Labview. I am trying to create an application that reads in applied torque vs angular displacement. I have a socket wrench torque transducer wired to an NI 9237 module for load/torque and the other wires go to an NI 9411 module for the quadrature encoder readings. These modules are connected to cDAQ-9174.I am able to see torque fine in MAX but I am getting nothing from the encoder. I have 5 wires going to the 9411

Yellow - Encoder GND wired to pin 12

Green- +5V wired to pin 4

Blue-CW Lead (Assuming A signal) to pin 1

Violet-CW Trail (Assuming B signal) to pin 3

White-ID Data (Assuming Z signal) to pin 2

I believe these are the correct pin connections as I have looked up many tips and exampless online and nothing has worked. I create a task in NI Max >> Counter Input >> Position >> Angular and when I test the signal, nothing at all happens. The acquisition mode is 1 sample... Any advice would be appreciated!

Thanks,

[Minions]

My first question would be what is the specification for the encoder?  Will a 5V input be sufficient to drive it?  Some encoders require 9-24Vdc as the input.  How many pulses per revolution?  That will determine the maximum rotation allowed by the 9411 rather than just spinning it.  Remember that there are four edges for each pulse specified (A^, B^, Av, Bv).  Once the correct voltage input is supplied, use a DMM to determine if the encoder output voltages (A, B, & Z) are changing when the shaft is rotated some.

[JÞB · Accepted solution]

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@jlduchar wrote:

Hello all,

This is my first post here as I am new to Labview. I am trying to create an application that reads in applied torque vs angular displacement. I have a socket wrench torque transducer wired to an NI 9237 module for load/torque and the other wires go to an NI 9411 module for the quadrature encoder readings. These modules are connected to cDAQ-9174.I am able to see torque fine in MAX but I am getting nothing from the encoder. I have 5 wires going to the 9411

Yellow - Encoder GND wired to pin 12

Green- +5V wired to pin 4

Blue-CW Lead (Assuming A signal) to pin 1

Violet-CW Trail (Assuming B signal) to pin 3

White-ID Data (Assuming Z signal) to pin 2

I believe these are the correct pin connections as I have looked up many tips and exampless online and nothing has worked. I create a task in NI Max >> Counter Input >> Position >> Angular and when I test the signal, nothing at all happens. The acquisition mode is 1 sample... Any advice would be appreciated!

Thanks,

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Assuming a single ended encoder A to pin1 is right but, B goes to pin2 and Z goes to pin3

You said only 5 wires to the 9411  You do have 2 other wires from an external power to Vsup and Com in order to supply 5V at pin 4 and power the encoder right?  (Yeah, if you want 5V at pins 4 & 5 you need an external supply - the 9411 only regulates the external source to 5V it doesn't generate it )

[jlduchar]

360 ppr, specified input is 5VDC which I assumed that the module would supply internally. Is it totally necessary for an external power supply? I thought that was only for voltages higher than 5V. Also I checked on an oscilloscope and the values were changing from 0-5V with 5V power supplied. This was with the transducer itself, not connected to the 9411.

[jlduchar]

Is that right? I will try supplying the 5V externally. I had assumed that it was supplied internally but for anything greater than 5V you needed an external supply. According to the pin outs in NI Max for NI 9411 it says A is pin 1, B is 3, and Z is 2. Contradictorily, the startup manual says A is 1, B is 2, and Z is 3 for single ended encoders. So there is some misconception there. I'm not sure which is right.

[JÞB]

If the transducer is self powered you don't need the 5V from the 9411 to power the transducer.

I also see what you mean by the MAX wiring diagram being inconsistant with the device manual (with a simulated 9411) I'd use my SSP and get an AE to explain that if I were you.

[perhult]

jldulchar>> Can you link or upload the data sheet or manual of your quadrature encoder?

Are you using the correct decoding? X1, X2, X4?

[jlduchar]

I have attached the specification sheet. It is a 3/4 inch drive torque socket transducer with 540 poles and a resolution of 3/16 degree. I am not sure if the decoding is correct or how I would determine that, currently I am using x4... It does appear that it requires 5VDC  which I am going to try to apply externally and see if that solves the problem.

[jlduchar]

Hey Jeff, just in case there is any confusion for anyone else out there, the MAX diagram is correct and the manual supplied is incorrect.