Encoder keep resetting if Z phase enabled

[RJ87]

Dear all,

I'm using NI USB-6341 USB DAQ with Labview 2015. I'm  OMRON open collect incremental encoder with 720pulse/rev.

I have all Phase A, Phase B, and Phase Z connected to 5V pull-up resistor. I checked the connection with ordinary counter. All the signal a counted correctly. All the ticks matched 720 pulse/rev. The index phase z triggers once every full rotation.

By using NI-DAQmx assistant, i'm able to get angular positions. All X1, X2, X4 decoding if working find without phase Z. But whenever Phase Z is enable for reset back to 0, the measured position keeps resetting at every count of Phase A and B (even slightest rotation, way before a complete rotation, or even close to indexing location).  like 0.25 -> 0, 0.25 -> 0, 0.25 -> 0. It keeps returning to 0 before measuring anything.

I wonder if phase Z enable captures the rising edge of a signal as high or the state of the input as high. Because if it's the latter, since it's pulled up, it's gonna be always high, and hence the immediate reset. If that's the case, is there any work around it? Removing the pull-up resistor doesn't return any values. What should I do to make crank position to work with open collector phase Z with NI-DAQmx assistant?

Regards

RJ

[Corey.Rotunno]

This thread is way old, but I guess I'll share my experience. I had the same problem, and I ended up with a solution that to me doesn't seem like it is very robust but it has been working and hasnt falsely reset ever. What I did is configure the Z input terminal as differential and hooked up the Z output from my open collector encoder to the PFI- terminal with a 5k pull-up and tied the PFI+ terminal to Vcc. That way when Z is active (goes low) the differntial is actually positive. When Z is inactive (goes high) the differential should be close to 0.

[will941]

Hi,Corey Rotunnoi

I now use PXIe6368 data acquisition card testing orthogonal encoder (E6B2 - CWZ6C 600 p/R 2 m), encountered such A problem, when I am not using Z index, A, B phase into acquisition card after A and B terminal, can be collected in normal Angle value of encoder, the encoder is A circle of 600 A and B pulse signal, when I will encoder Z Z terminal connect into the data acquisition card, enabling the Z index, data collected have been 0, 0.15, 0.3, 0.45, loop transformation, Instead of counting from 0 to 360 after the Angle has reached 360 degrees.

7 is the data collected without Z index, and 8 is the data collected with Z index