Can't interpret signal coming from photodetector

[Baljitwork]

HELLO,

I just made a simple VI for acquiring Analog signal from external source. IN my case, Analog signal from function generator, it is able to interpret signal and display it on my screen very well. but when i connected my photodetector output to my NI USB 6002. it is not able to interpret electrical signal coming out of photodetector. 

PHOTODETECTOR We are using [DET08CFC/M INGaAs Biased detector]

What is the main reason? is it related to impedance or there is some modification to do in my VI. please do guide and advise me.

We connected photodetector input with laser diode controller output with the temp 25C. and current = 93.4mA. 

[Henrik_Volkers · Accepted solution]

How is the photodiode connected to the 6002?

(Here details are important 😉 )

How fast are your expected signals?  This PD is quite fast and your 6002 is quite slow ..

The input range of the 6002 is fixed to +- 10V , what signal range are you expecting?

Do you have a o-scope somewhere to have a look at your signal ? 

In the manual to the PD are some trouple shooting hints 😉

[NIquist · Accepted solution]

Have you checked the battery? 

Do you have a proper load (50 ohm) on the output?  The detector outputs current so you won't be able to read it with your DAQ without a TIA or impedance matching load.

Do you have a simple DMM so you can verify a current output without worrying about the DAQ and software issues?

Are you sure you are feeding the detector enough light in its wavelength?

+1 to Henrik about the manual.  Look at page 8 for wiring instructions...   DET08CFC_M-Manual.pdf

[Henrik_Volkers · Accepted solution]

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@NIquist wrote:
...

+1 to Henrik about the manual.  Look at page 8 for wiring instructions...   DET08CFC_M-Manual.pdf

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+1 is a KUDO 😉

RTFM (Read the f'antastic' manual) is always a good source for troubleshooting!