Angle Measurement Using Incremental Encoder and NI-9361

[Parthiban_SM]

Hi,

My requirement is to measure angle using incremental rotary encoder. I have made the hardware wiring and tried to capture angle using NI MAX. The result showing irrelevant values(360 degree rotation in clock wise and counter clock wise showing the value of 620 and 140 respectively. The values keep changing in every 360 degree rotation. I have reset the initial angle to zero before each 360 degree rotation). Please share your thoughts regarding this problem.

Thanks  

[Kevin_Price]

Erratic or inconsistent angle measurements can be a symptom of having almost-but-not-quite electrical compatibility.  So, close enough to work *some* of the time, but not reliably.

The presence of pairs like A, A often imply a differential output.  On the other hand, the push-pull designation is something I've always associated with single-ended output, but I'm not EE-level knowledgeable about these things.

With your 24V supply, your module needs to operate in single-ended input mode.  I haven't used a 9361 -- is that a configuration option you can specify?

Have you observed the A,B,Z signals (relative to DGND) on a scope?

-Kevin P

[Parthiban_SM]

Much awaited replay thanks Kevin, After your message I check out the NI MAX configuration, There is an edge count option, using this I captured A and B channel count individually I got the values of 100000 and 120000 thousand respectively(with respective GND connection). there is no single ended input mode config in NI MAX while using NI 9361.

and also I have configured angle measurement in NI MAX, and connected A B Z channels with their respective GND. Observed 360 degree in one direction and 470 degree in another direction with initial angel set to 0 before each rotation.

while I rotate counter clock wise 360 degree after clock wise 360 degree rotation with out set initial angel to zero, I got -120 degree in all the decoding types(X1,X2,X4)

while I select decoding type as Two-pulse, the output was 363 in Clock wise and 357 in counter clock wise direction. here the problem is if I rotate counter clock wise 360 degree after clock wise 360 degree rotation with out set initial angel to zero the value is increasing, which means after 360 degree rotation in both the direction has shown the value nearer to 710 

Share your thoughts in this regard

-Parthiban

[JB]

I would perform a test by connecting pull-up resistors (1k to 10k) to the outputs of the encoder.

• PFI0+ --> Vout
• PFI4+ --> Vout
• PFI7+ --> Vout

[Zhangfy]

Hi

I am also testing this similar incremetal encoder with A,B and Z to get the speed measurement. Did this suggestion from Mr.JB work?

With the answer from Mr.JB, the analog voltage will be calculated, right?

would perform a test by connecting pull-up resistors (1k to 10k) to the outputs of the encoder.

• PFI0+ --> Vout
• PFI4+ --> Vout
• PFI7+ --> Vout