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LabJack U3-LV advice

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sim
sim92's picture
LabJack U3-LV advice

Good afternoon, I have some doubts related with the Labjack U3-LV.

What I need to do is to connect a photosensor (H10722 – HAMAMATSU) to a Labjack U3-LV to obtaing an output signal in the computer programme LJControlPanel.

https://www.hamamatsu.com/resources/pdf/etd/H10722_TPMO1063E.pdf

I am not sure if I am doing the connection right.

What I think is:

•Low voltaje input (RED) to VS.

•Low voltaje input (GREEN) to GND.

•GND (Black) to GND.

•Vref OUTPUT (Blue) to nothing.

•Vcont INPUT (White): to FIO (It should be regulable: +0,5V to +1,1V)

SIGNAL OUTPUT to ??

Can you give me some advice or feedback?

Thanks in advance.

LabJack Support
LabJack Support's picture
It appears that your sensor

It appears that your sensor requires +/-5V supply, so you will have to provide that bipolar power supply and connect it to RED, GREEN and BLACK on the sensor..

Then you want to connect Sensor-SIGNAL to U3-FIO0, and connect Sensor-GND to U3-GND.

Not sure if Vcont is required or optional?  If required you can connect Sensor-Vcont to U3-DAC0, then set DAC0 as desired.

The input range of the analog inputs on the U3-LV is 0-2.4 volts (normal range) or 0-3.6 volts (special range).  It is not clear, but I think your sensor gives -4 to +4 volts.

https://labjack.com/support/datasheets/u3/hardware-description/ain

https://labjack.com/support/app-notes/signal-voltages-out-range

 

sim
sim92's picture
Thank you so much for the

Thank you so much for the quick answer.

I think the sensor gives +4 Volts.

How do I know if my range is "especial range" 0 - 3.6 Volts in my LabJack U3-LV?

If my range is 0-3,6 Volts, is it necessary to use a LJTick-divider or a voltage divider circuit?

I attached you a photo with the circuit. Can you tell me if it is correct?

Thank you.

LabJack Support
LabJack Support's picture
You decide whether you use

You decide whether you use normal or special range.  For testing, use the Test panel in LJControlPanel.  Under "Neg Channel", "SE" is the normal single-ended 0-2.4V range and "0 - 3.6" is the special range.  Jumper DAC0 to the analog input and then adjust DAC0 to 2.3 or 3.5 volts.

If the signal indeed varies 0-4 volts, you can acquire most of that range with a channel configured for the special range.  I suggest you adjust the sensitivity of your sensor so it stays below 3.6 volts at your max condition.

Yes your diagram looks correct.  Use the Test panel in LJCP for your initial testing.  Once you figure out what value you want DAC0 set to, use Config Defaults in LJCP to make that the default.

 

sim
sim92's picture
Good morning,

Good morning,

I hope you are doing well.

My signal output has a coaxial cable. Is there anything that I should take into account?

Thank you.

LabJack Support
LabJack Support's picture
Coax cables are good for very

Coax cables are good for very high frequency signals, but they are used in all sorts of strange applications so the fact that your sensor uses a coax does not tell us anything definitive.

You will need to break it out to +/- leads somehow, so might want some sort of BNC breakout:

https://www.jameco.com/shop/keyword=Bnc-Breakout