Connection Diagram for SCXI-1102 with SCXI-1303 Connector Block

[pallen]

Hello folks,

Just got my shiny new SCXI goodies in for current project.  I got it all hooked up to my PXI-1042 with no problems after just a few minutes of reading. 

I noticed that a thermocouple shipped with either the SCXI rack itself, or with one of my Thermocouple modules.  I figured I'd use it to do a quick test to make sure I'm getting a reasonable signal back.

I created a Global Channel in Max. Set things the way I wanted.  Then I had a look at the Connection Diagram.   That's when things didn't seem quite right.


I wasn't sure at first.  But I though the red wire was usually the negative on a thermocouple.  I hooked things up according to the Diagram anyway to test it out.  Sure enough, it appeared to be backward.  I flipped things around, and now it seems to be reading the room temperature as well as the response to me holding it very well.

What I'm wondering now is if this is just an error with the Connection Diagram, or if there's something else I might have configured incorrectly.  (This is my first time using this hardware)   Does anyone know? 

[PBear]

Hi Patrick,

Sorry for the confusion. You are correct in all of your assumptions so don't feel like NI has flipped your world upside down! The reason this appears backwards is because no matter what thermocouple type you have or the task you are setting up, the connection wires will always show a red wire coming from your signal's positive to positive on the DAQ device and a yellow from negative to negative. For example, if you set up a standard analog input task, the same color schemes apply when attaching a signal generator to the AI channels on a DAQ card. This can obviously be confusing when connecting a K-type thermocouple as the wires for a K-type thermocouple are opposite of what our connection diagram shows. Our connection diagram does not reference ANSI color codes for thermocouple types. This is a product suggestion that has been kicked around and the more users like yourself that give us great feedback like this, the more aware we are of this condition.

So don't worry, you are connecting your thermocouple correctly. Just pay attention to the wire types that it says you should connect to each terminal and disregard the color of the displayed wires.

Message Edited by Patrick_B on 04-17-2008 04:25 PM

[RavensFan]

Hi Patrick,

Here is a link to another thread where this same question came up.

http://forums.ni.com/ni/board/message?board.id=170&view=by_date_ascending&message.id=303918#M303918