Measuring PWM Signal with NI9423 with C-RIO 9073

[AdnanZ]

What's the question?

[Steven Tan]

Eh..sorry. I do not know what happened, but it seems like my questions is gone in my previous post.

Let me recap, I'm new to NI Components and LabView.

I wanted to measure 8 PWM Signal generated from a controller (200Hz, Max 4A, 24Vdc).

WIth NI engineer's suggestion, I bought cRIO 9073 and NI 9423 for this purpose.

I have created a VI for this purpose. It seems to be working at first, but later on, the value read by the NI 9423 becomes unstable even though the out put signal from the controller was stable.

The value read by 9423 just goes up and down with an increasing PWM signal from my controller.

below is the setting for the 9423.

Thanks.

[KateB]

Can you provide below information:
1. Where is the signal that you measure from, and how do you connect it to 9423? A schematic attached is appreciated.
2. You said it's unstable. How unstable it is? How large is the value swing?
3. Have you tried enable input filter? Give it a try and reply whether it helps?
4. Can you attached your whole project for further analysis?