How do you apply custom thermocouple scales?

[CarolK]

I am using a 9211.

I have created several Thermocouple tasks in MAX and I would like to apply a custom scale to the readings as the cards are reading high.  I've created my scales but the Thermocouple task does not have the drop down box for applying a custom scale. 

I went to my Vi and created the thermocouple task there with DAQmx Create Virtual Channel with the polymorphic selection set to AI Temp TC.  I selected the units to be From Custom Scale however, there is not an input to put the Scale name.

Is it possible to apply a custom scale (mx+b) to a thermocouple input?  Or do I need to do this through the calibrate feature of the card in MAX?

[Denver_]

Hi, 

Are you applying the same scale to all the channels. You dont need to create multiple tasks. Jst create one task and include all your channels in that task.

If you are using DAQmx VIs for your programming, you can then give the custom scale that you want applied to these channels...as shown below.

[CarolK]

Can you try applying that scale when you change the Polymorphic VI selector for AI Voltage to AI Temp TC?  Once you change the type of VI it is, the custom scale input is gone.  I chose the AI Temp TC as the VI type because my input TC is automatically read as deg F.  However, I still have an offset that I want to adjust with an mx+b scale.

[Jordan F]

You can not directly apply a custom scale when using a AI Temp TC task.  This option is not available the same way it is with a general voltage acquisition.  Another option would be to apply a scale using math functions after the data is returned in LabVIEW.  Also, you could acquire the temperature as a voltage and use the built in custom scale feature.  

However, I am curious as to why you need to apply a scale to your temperature task.  There may be something wrong with the connections, calibration, etc. that could be the source of the problem.  This might be worth checking into before you try building a scale with extra math.