physical channels

[jadkassab]

hey , i have a problem with physical channels in the DAQ assistant .

I have pressure sensor , torque sensor  and a flow sensor that i want to test them.
in other hand , i have the DAQ(USB-6001) , labview 2012 and NI-DAQmx 15.0.1 .

When i want to put analogue input in the DAQ assistant , the physical channels channels appears in "voltage ,temperature, current .." but don't appear in "pressure , torque and some others "

What do you think is the problem ?

[Bob_Schor]

I think the "problem" is that you are using the DAQ Assistant, which is designed as a "simple" approach to DAQ, hence is unsuited for even slightly-more-complex tasks.  Read this excellent White Paper and replace the DAQ Assistant with a small amount of real DAQmx code to do exactly what you want to do.

Bob Schor

[Dennis_Knutson]

My opinion is that the inexpensive device does not support those measurement types. That could be because it lacks built in excitation, etc.

[Sam_Sharp]

I think you need to use a custom scale - I think the pressure/torque options are for devices that have a built-in bridge circuit. Since you're not using one of those devices, you need to read in the voltage from the sensors and use a custom scale to convert from Volts to Pressure/Torque/Flow.

[natasftw]

All of your sensors are voltage measurements.  You need to know how to convert those volts into your unit of measure.  The other options are just there to make things easier for you.  it's still generally a voltage measurement.

[jadkassab]

please can you tell me where exactly i should focus in this paper ? or can you give an example on how to convert from voltage to pressure or torque? i am new in this software.
thank you

[Sam_Sharp]

LabVIEW has 100's of examples built-in. Go to Help -> Examples and search for DAQmx. You can probably search for 'custom scale' and get an example for that too!

[Dennis_Knutson]

The details for the conversion will be in your sensor documentation. You have to read that first and understand it. After that, it's generally basic arithmetic. You should not be new to that

[jadkassab]

i tried to create a virtual channel and look what happened .... 

[Dennis_Knutson]

No, the device does not support a bridge measurement. That is the same reason you can't use the DAQ Assistant. You were told to create a voltage measurement.