Creating VI for photodiode detector. Help me

Question

Hi,
I am student and doing research on liquid crystals for LCDs and smart windows. Recently, my Professor bought some NI Hardware and two photodiode detectors.
details of my setup is given below,
1. photodiode detectors (PDA36A-EC Si Amplified Detector, ThorLABS) here are detector specifications
2. NI cDAQ-9172 and NI9205 module which is analog input 10V.
3. 632.8nm HeNe Laser.
I want to measure the light intensity on photodiode detector. the response time of LIQUID CRYSTAL CELL to electric feild in milliseconds (ms). Now I want to know that how can I make such VI by which I can measure the light transmittance and sve the signals to a file? I am new one to this feild and no one knows, how to use this setup. plz help me out in wiring the photodiode detectors wiring to module NI 9205 and making VI.  Thanks alot.

Answer 1

My suggestion is to hold off on the code for right now. Your first order of business should be to connect the sensor to the DAQ module. The sensor has a BNC connector. Do you have the 9205 with the D-sub connector or the spring terminal connector? If you have the D-sub you'll need to make a cable, which isn't that difficult since you're only talking about one signal. You may want to consider getting the 9933. Either way don't forget the 50 terminating resistor at the DAQ module end if your cable is longer than 12 inches. If you can, keep this cable short. If you don't have the skills to make the cable, then just find someone - there must be someone there who knows a little about electronics, and it's not like you woud be asking them to rebuild Apollo's landing computer.
Once you've done this you can use Measurement and Automation Explorer (MAX) to test the connection and make sure the DAQ system is reading correct voltages. MAX provides test panels so you can see what the DAQ module is reading. Thus, you can vary the laser and see the voltage change on the test panel. MAX is installed automatically when you install LabVIEW or DAQmx (which you will need if you don't already have it).
Once you've gotten this far then you can look at what you need to do with the LabVIEW code. In your case it will probably be a simple loop with a DAQ Assistant Express VI to collect the data and a Write Measurement to File. Both are Express VIs which have dialogs for setting up how they work. But, like I said, get the hardware connected first, then worry about the sofware. 
P.S. By the way, is this in any way related to your query from a few months ago?
Message Edited by smercurio_fc on 05-03-2010 11:02 PM