Voltage Limited on myDAQ

[greigh]

I am new to using myDAQ, but I am running into an issue with the analog voltage output. I am trying to create an output of 5V, but the most I can see with the multimeter is 4.2 volts. When I lower the voltage output to anything below 4.2 volts it is accurate, but anything above 4.2 volts only displays 4.2 volts. I tested the multimeter on a 9V battery and it displayed ~9V. Is this limited by my USB port? I've been searching for hours. Any help would be appreciated.

[Bob_Schor]

The myDAQ has a maximum power output (I believe) of 500 mW (drawn from the USB connector), largely composed of Analog and Digital Output lines.  What load are you trying to drive?  Note that 500 mW = 0.5 W = 100 mA at 5 V, which is consistent with the USB 2.0 specification that the myDAQ uses.

Bob Schor