CompactRIO geartooth hall effect sensor

[milad]

Hi

I am newbi with labview and NI and  i have Compact Rio with a few modules on. And i also have a hall effect sensor (Gear Tooth manual)which has 3 wire +/- and earth so what I am trying to do is to measure the engine RPM. Im using this module 

NI 9403

32 Ch, 5 V/TTL Bidirectional Digital I/O C Series Module  module

I have seperate supply voltage for the sensor.

I know that earth wire need to go to COM pin on NI9403 but how do i get it to disply on labview because in labview i only have access to 32 I/O channel and they all boolean(is there any away to change this.).any idea am i using right module or need diffrent module? By the way im mechanical engineering student and i dont have much electrical background...

[milad]

HELP PLEASE

[Chris_Garratt_NIUK]

Hi Milad,

You should be able to do this fairly easily in LabVIEW. You will need to set up a task in LabVIEW that measures the frequency of a pulse train. You should be able to find this in the LabVIEW examples. Try looking for digital counter frequency measurements in the examples. You may need to find out exactly how you need to interpret this frequency if you need to convert to RPM.

You will only need 1 digital line to perform this task. The module you are using should be suitable but I am not sure how you should connect the actual output from the hall effect sensor to the DI line. You should just have one voltage which you can connect to 1 line of the 9403. As long as you know which line you have connected to then you just need to read that line.

This is a link to the spec sheet which contains the pinout for the device.

Let me know if you need some more advice.

Regards,

Chris

[milad]

tanx for replying.

My sensor have 3 wires red, blue and black. red is connected to voltage source black in connected to COM pin in 9403 and blue is connected to pin 0 I/O in 9403(which is Input). my problem is when i drag and drop DIO0 from my project to block diagram VI the DIO0 is a boolean and i can not change it to any other data type say double when i right click on the properties on DIO0 in the project i get a panel with lots  data type but im not able to select any of them the only thing that im able to change is the iput or output. is there anyway that i could do this?

Many tanx Milad

[milad]

how to get the input DIO0 to be displayed in graph in labview?

[Chris_Garratt_NIUK]

Hi Milad,

Have you looked at the example I suggested? The signal generated by your hall effect sensor is a digital counter signal which means the data type IS boolean. You need to acquire it as a counter and measure its frequency to get to the RPM. It sounds like you have the hardware wired correctly. All you have to do is set up a counter frequency measuring task on DIO0 and you will get your changing frequency.

Get back to me when you have got to this point.

Best Regards,

Chris

[milad]

Tanx for replying

I think I have figured out the block diagram correctly. But i didn't get any data in the Labview. I did a test i connected DIO0 input to a LED light, so it should have switch on and off as field around Hall Effect sensor distorted but nothing happen. so i think my wiring is not correct. Just a few question about NI 9043.

1.Dose the DIO0 input has to be +5 volts? in my case was about 10V.

2.If NI 9043 connected to CompactRIO so it gets its power supply from the CompactRIO am i rite? What is RSVD on NI 9043?

3. If i want to light up a led say out of DIO1 (output) when RPM is 10000 would i be able to do this? What is the voltage output from this pin (DIO1)?

I really appreciate your help

Cheers Miald

[milad]

Is My Block Diagram and wiring right ? Im getting no data on my labview graph... am I doing something wrong? hElP PlEaSe

[Chris_Garratt_NIUK]

Hi Milad,

The link below will take you to the data sheet for the Ni-9403.

http://sine.ni.com/ds/app/doc/p/id/ds-165/lang/en#requirements-section

It should be simple to get the LED to light when the RPM goes over 10,000. All you need to do is read the RPM and then use some logic to get the LED to light when the RPM is greater than a value you assign (eg.10,000). Can you tell me one way or another whether you have looked at the examples in LabVIEW? I really think they will help you get some actual results in LabVIEW. The code you are using at the moment isn't ideal.

Best Regards,

Chris