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Analog Output NI DAQ 6366 voltage levels


  Im new in using this DAQ with Labview. Im trying to use one of the Analog Output channels to control a device which requires 5 volts. I set it up to send the 5 volts as a DC analog output, but when is connected to the device I only measure about 500mVolts. Only when I connect to a scope and set the impedance to 1 Mohm I can measure what I set up on the labview code. 


Is there is a way to setup to get the full voltage amplitude out when connecting to a 50 ohms?



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Go read the specification.  There is a parameter for maximum output current.  It is usually in the 4mA range.  Due to that limitation, you cannot drive into a low impedence.  Add in a buffer circuit.  A simple op-amp in a voltage follower configuration should do it.

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It sounds like you are dealing with a drive strength issue (as stated above).  According to the 6366 spec doc the output drive current is 5mA max (a 1kΩ load for a 5V output).


Remember that you also have a User +5V pin available that can source 1A at 5V.  This is always on and is not adjustable.  If you just need to power something then you're all set.  If you actually need a 5V signal you can buffer the AO and power the buffer from User +5V using a rail-to-rail opamp.  Anything other than a rail-to-rail amp will reduce the max output voltage. Ensure that it is unity-gain stable if you plan to simply buffer the signal (gain = 1).  



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