Shaft Encoder With CompactRIO

[LREng86]

Hi,

Apologies if the following is slightly vague.  This is my first attempt at LabVIEW and VI development and compact RIO so I am just trying to establish if what I am proposing is possible and the hardware required.  I was hoping that someone in the community would be able to point me in the right direction.

I am building a small test rig, which has an incremental push pull rotary shaft encoder with A and B outputs, along with an index/Z signal.  The encoder has a 5 to 24 V DC input voltage, and has 360 PPR.  This is used in conjunction with a 3 DOF sensor with a CAN bus output. 

I have access to a compact RIO and Compact RIO CAN bus module, along with the LabVIEW real time and LabVIEW FPGA programming modules.  I am in the process of determining what other compact RIO modules I have access to.

I am looking to achieve two things from the program –

1. Calculate and display the RPM of the rig from the rotary encoder signal. The RPM doesn’t need to be changed in the program this is adjusted by another means.  The maximum RPM of the Rig is 1500 RPM.

2. Log the data from the force sensor and as part of this include the Z signal from the rotary encoder. So that I can interrogate data at a later stage and determine how the forces change with rotation from a known datum position.

What I would like to know is what would be the best way of connecting the encoder to the compact RIO, and what module(s) if any would be best for connecting the encoder along with the DAQ logging requirements.  If it is possible and whether or not there are any tutorials that I could use along similar lines to increase my knowledge and understanding of LabVIEW/compact RIO. 

I want to learn how to set it up correctly, but like I have said this is my first time with LabVIEW and am not sure quite where to start.

Any help would be much appreciated.

[Tom-S]

Hi,

I recommend taking a look at the CompactRIO developer guide:

http://www.ni.com/compactriodevguide/

This contains a lot of the information you will require to get started with your cRIO.

With regards to measuring your encoder, the module you require depends of the type of encoder you have and its output. A simply digital encoder should work with most DIO modules that has a counter function. Similarly with your force sensor, this depends on its output, for example it could be strain guage based or internally amplified etc. If you like specific information regarding this, I recommend contacting your local branch and asking to speak to the Sales Department. Our engineers will be able to go through your requirements with you and make recommendations for modules based on this. You may also need to look at the FPGA module, if this is something you are interested in using on your cRIO.

I hope this helps.

Tom

Applications Engineer

NI UK