PLM-ADIN problem

[camcam85]

Hello!

I have a problem with the PLM-ADIN extension card I bought.
I have a ProfiLux 3 eX and the firmware is 5.11.

What I wanted to do is connect an irradiance sensor (W/m2) for a photobioreactor.
The sensor has an analogical exit of 0-10 V.

So, I installed the PLM-ADIN and I connected the sensor exit to the D-subminiature (DE-9) in the pins 6 (Analog input 1) and 8 (GND).

The PLN-ADIN is found in the Profilux and give me the two Voltage values. But the values are always zero.
The sensor works I tested with a Voltmeter and the volt increase following the warm or the light.

Any clues?
Tank you very much in advance!

[Gunther]

You can test if the card is working by connecting Pin #1 to pin #6 - you should get the 10V.
If you insert a resistor in the wire, the value should decrease (20 kOhm ~5V; 1 MOhm ~0,2V ....)

Maybe the possible load of your signal is too low for the ADIN card. You can test that by connecting a 20 kOhm resistor between the GND and the 0-10V output of your sensor (aka create a short-circuit with a 20 kOhm resistor). If the voltage between the connections drop down, the signal load is too low for the ADIN card

[camcam85]

I tried to connect the pins 1 and 6 and the measured voltage was 10 V.
I also inserted a resistor of 270 Ohm (the only I have) in the wire and the voltage decreased to 9,94 V.

I haven't understand exactly what do you mean with the second paragraph:
what is the difference between the first circuit with the resistor to test if the card is working?

Something like this? (R= 270 Ohm)
2013-01-29 10.43.43.jpg Voltage 1 = 9,94 V
1.jpeg Voltage 1 = 10,00 V
2013-01-29 11.20.48.jpg Voltage 1 = 7,30 V

Anyhow, if the problem would be the low load of signal, can this be solved in some way?

Thank you very much!

[Gunther]

I tried to connect the pins 1 and 6 and the measured voltage was 10 V.
I also inserted a resistor in the wire and the voltage decreased.

So the ADIN card itself is working properly

I haven't understand exactly what do you mean with the second paragraph

Maybe a little sketch will make it more clear:130129adin.png

Measure the sensor voltage without the ADIN card (the 20 kOhm resistor simulates the internal resistance of the ADIN). If the voltage drops down with resistor, the sensor can´t be used with the ADIN the card directly.

if the problem would be the low load of signal, can this be solved in some way?

That´s not so easy. You need some kind of isolation amplifier with 1:1 rate

[camcam85]

Ok I did what you told me without the ADIN card but actually it was always 0,0 V with or without the resistor.
So I measured the output of the sensor with the voltmeter and it was 0,0 V. I thought that probably the light of the office wasn't so good for the sensor and I placed on the sunlight and the volts were 2,7. I connect everything again and now works! Sorry for the inconvenience