Help on Lm35 with a Pci-6040E daq device

[Bharath kumar]

Hi..
Im a student and Newbie to this Daq stuff .Did learn quite a bit to do some basic things in Labview .

I recently got one daq device and I am very  excited about it .I wanted to do some small experiments like temperature logging using a LM35DZ sensor and my 6040E daq device .This is where i ran into problems .
I did configure the DAQmx Assistant with the following parameters :
Channel settings : Voltage
Signal Input range : Max 6 Min -1 ( Since max voltage O/P by the LM35dz is this ) datasheet is attached
Terminal Configuration : RSE

My question is that when i Run the VI I do get these problems
1. The waveform graph X-axis Time does not continuous with respect to time it just is stationary to some certain value.Its not real time
2. The thermometer Indicator is always zero  it does not change no matter what voltage it gets.

What should I do inorder to make the voltage proportional to Temperature. Some Interpolation or something .If im going to interpolate My readings are not going to be accurate enough.

Should I use Temperature ( Thermocouple K ) as my Channel Setting rather than voltage

If some one could construct a VI for me it would be helpful.
i have done one myself I have attached it.Please tell me what is wrong with that .

[Wayne.C]

Have you tried using the test panel in MAX to verify that your sensor is properly connected to your DAQ device?  You should see 10mV of ouput voltage for each degree C.

[Bharath kumar]

I had 1.47v at room temp .The room temp was 34deg centigrade .
There is absolutely no relation between the voltage and room temperature...

[JB]

• Supply the LM35 with 5V. As an alternative to a power supply, you can use the +5V output of the DAQ board.
  
• If using a power supply, connect its GND to AIGND of the DAQ board.
• Connect the output of the LM35 to an AI (eg AI0).
• Make a NRSE measurement.
• Let us know if this works.
  

[Bharath kumar]

I Used a 10v supply because i heard voltages less than 5v  make the LM35dz seems to be very unstable at 5v supply voltages..
i dont think there is a prblem in connection ..
well it shows zero if its not connected to my DAQ so I dont think there is a problem in connection so there must be something wrong with the configuration on the software side

[mireia]

hi. ai have a similar problem. I want to masure the room temperature with a lm35dz, but i dont't know how to configurate daq assistant. If you already know that please help! (the lm35dz use ai2)

[Ana P]

Hi mireia,

I want to point you to this Developer Zone: Getting Started with NI-DAQmx: Using the DAQ Assistant. There you will find Using the DAQ Assistant to Automatically Generate LabVIEW Code and NI-DAQmx Express VI Tutorial that might be really helpful in understanding how to configure the DAQ Assistant for your application. You can follow the steps explained here, but instead of creating a Voltage task you can create a Temperature task. I hope this is helpful,

[HeReL]

Hi all,

I have few problems in connecting my LM35CZ temperature sensor with PCI-6024E. By the way, I am using LabView version 6i.

I followed the connection as mentioned by JB, but the reading is rather confusing, as I cant relate the reading to the room temperature that I measured.

With NRSE, the output from the LM35CZ (measured by multimeter) is 0.4 V, but reading in my MAX is 1.6 V.

With NSE, the output from LM35CZ still 0.4 V but reading in MAX is 0.3 V too.

The room temperature measured using thermometer is around 20 - 21 Deg Celcius. Appreciate if someone can help me on this matter.

Thanks.

[HeReL]

Can anyone help me with the problem?

Btw, correction from my original post. With NSE, the output from LM35CZ still 0.4 V but reading in MAX is 0.4 V too.

[HeReL]

Extra information,

As I tried to manipulate the temperature using a lighter, the output voltage is going down as I put a lighter next to the sensor. It supposed to be giving bigger output voltage isn't ?