WHICH INPUT CHANNEL HAS TO BE INITIALIZED , analog input CH or digital input CH for DC VOLTAGE?

HELLO,

i have DC voltage(2.5V) which i want to plot using NI USB 6255, whether i should use the analog input or digital HW channel has to be initialized.

even if i acquire data from digital i/o channel i will get logic 1 or logic0 so how to obtain the same voltage which i give as input

plz anyone help me

Manjunath

Answer 1

[Pedro Villena]

If you want to plot the exact voltage in matlab, use an analog input channel. The digital channels are in TTL range voltage (0-5 volts), and if you adquire a signal of 2.5V, you will get a noisy digital signal [0 1].

or

Try to configure the analog channel in Differential Mode. In this mode, you gonna use 2 channels, one for posistive pole, and the other for negative pole.

[MANJUNATH]

i want to plot 2.5V, its supply from battery (chargeable cell), i tried with analoginput but the plot was same even when the signal input was removed .

[MANJUNATH]

thanks for the support Mr. Pedro Villena , problem got resolved , a grounded resistor was added before the signal being connected to DAQ.