SCB-68 connection signals

[Multifunction_Card]

Hello,

I am using a pressure sensors (0 to 10 bar) connected to the railvehicle, that needs 24 V DC supply and generates a 0->5V output.

I would like to read this voltage using Labview 7.1 and DAQCard 6036E. I am using DIFF mode.

I have attached a simple photo of the ways to connected the sensors.

Could you tell me, is it correct ?

Any kind of help would be great!

Thanks,

Marian V.

[Brian F.]

Hello Marian.

Thank you for posting to the NI Discussion Forums. 

Upon first glance, you seem to have the correct idea on connecting the pressure sensors.  However, I am a bit confused by your setup so I would like to clarify a few things.  First, I am assuming that the 2 rows of screw terminals that rest in the middle of your diagram are terminals on the SCB-68.  I see that the bottom row are pins 1-26.  What pins does the top row correspond to?  The general format that you need to follow to take correct measurements under differential mode is to connect the positive and negative terminals of the pressure sensor to seperate analog input channels on the card.  If you are following this format, you should be just fine.  I would recommend testing one pressure sensor before you hook all 6 up to make sure that your configuration is sound. 

From the SCB-68, you are connecting to a 6868LPR before you connect to the 6036E DAQ card.  Is there a reason that you are doing this?  Some clarification on this matter may be helpful as well. 

Finally, what type of pressure sensor are you using.  To fully confirm that you have the correct setup, I will need to refer to the specs of your specific pressure sensor. 

Let me know if you are successful in reading just one pressure sensor or if you are having specific problems and I will be glad to assist you further.  Have a great day!

Brian F
Applications Engineer

National Instruments

[Multifunction_Card]

Hello,

I am using a pressure sensors (0 to 10 bar), type TSZ (www.meret.sk, 3 wire connection).

I have attached a new simple photo of the ways to connected 2 sensors.

Is it correct now ?

Thanks,

Marian V.

[Brian F.]

Hello Marian.

I am still confused by a few things.  On your new diagram, what are the 1-4 pins and the 23-26 pins?  I also recommended testing one pressure sensor before you hook all 6 up to make sure that your configuration is sound.  Have you tried this?  If so, how did it go for you?  If something isn't correct, what error or incorrect reading are you getting?

In your previous post, you stated that you were using an SCB-68, connected to a 6868LPR before you connect to the 6036E DAQ card.  Is this still the case?  If so, is there a reason that you are using both the SCB-68 and the 6868LPR?  Some clarification on this matter would be helpful as well.  As far as the connections made to the 6868LPR, it looks good since you are hooking up the positive and negative terminals to take a differential measurement. 

Let us know the answers to the above questions and we will be happy to help further.

Brian F
Applications Engineer

National Instruments