Using Arduino to drive National Instrument NI 9411

Hi Forum:

I am trying to send a pulse of 5V, 5 millisecond from PIN 7 (or any output pin, for that matter) to NI 9411 6-Channel Differential Digital Input Module. As you guys can see page on page 16/17 of this manual http://www.ni.com/pdf/manuals/373506e.pdf , the input current rating of this input module is mere 1-2 mA. I am thinking Arduino Uno can provide this much of current. Things have not worked till now.

My first question is, can I programmatically access the current through PIN 7 as the current through the PIN is so low (is that true?), my current probe w/ Tektronics oscilloscope is not able to pick up? I am not sure if any current actually flowing through it not. PS: I can see the voltage pulse of 5V off the PIN7 on the oscilloscope.

Has anyone ever tried to work with NI controllers/DAQs with Arduino? Any help is much appreciated.

A simple pictorial representation of what I am trying to do is also attached.

Thanks Bugaboo

Hi, can your oscilloscope see the voltage pulse coming out of the aduino? You also need to connect COM of the NI9411 to gnd of the arduino.

Tom...... :)

You nailed it, mate.

I was connecting the ground of Arduino to DI1b. When I connected the Arduino Gnd to COM, it worked like a charm.

However, I am bit confused. If I connect both DI1b and COM to Arduino Gnd, then it stops working. I wonder what is the purpose of DI1b. You seem to have worked with both (NI 9411 and Arduino). Any idea?

Thanks Bu

Hi, Bu, good that it is working, DI1a and DI1b are differential inputs and the difference between the pair dictates the logic state of low or high. Your application is what is called single ended and leaving DI1b open is the valid way of using your input, so don't worry about DI1B, page 11, figure 4 shows your configuration.

Good luck with the rest of your project.

Tom..... :)