How do I count digital pulses and convert them to an x-axis unit?

[ProgChemist]

I am a grad student in Chemistry and I have undertaken a project to switch an old spectroscopic instrument from a stepper motor chart recorder to a digital interface. 

I am using Labview 7.1.

I just measured the signals coming from the instrument, so I know exactly what I am working with.

I have one constant, 100mV, digital pulse--which was used to drive the stepper motor a set # of wavenumbers for a given amount of pulse. I need to convert this signal to correlate with wavenumbers--on the x-axis of my final waveform graph.

 The other signal is an analog signal, up to 250 mV, which is coming from a photomultiplier tube and represents my y-axis of my final waveform graph.

I am using the NI BNC-2110 DAQ board. 

Should I design the program based from just the AI Aquire Waveform.vi? Add a Count Events or Time vi. for the digital pulse?

Could anyone give me some hints with my initial setup/layout? 

[Ben]

Hints:

Figure out what is the modle number of your DAQ device. I think the model you cited is just a break-out box.

Depending on your hardware you may be able to use the step pulses to clock your A/D conversions.

The number of sample will be the number of steps so all you need is a conversion factor to convert sample count totoal to wavelength.

Others may offer better ideas so stand by.

Ben

[ProgChemist]

Thanks Ben.

Yes, I did give you the break out box model #. My DAQ # is PCI-6251.

 I was also wrong about the signals.

Both signals are analog.

The x-axis signal give used to incrementally move the stepper motor in the old chart recorder by pulsing at every time x.