how to turn on/off relay using NI DO 9476??
Just write a TRUE or a FALSE to the digital output. The 9476 will just create a connection when set to TRUE. So just apply your voltage to one side of the relay coil, the high side of the 9476 channel to the other, and the low side of the 9476 channel to ground. You should also include a flyback diode across the coil to avoid some nasty current spikes.
can i do the same using AO module??
Not likely purely due to current constraints. Besides, it is way easier to control a digital line than an analog.
can i get the sample labview script to handle relay using DO??please try to share.
Help->Find Examples. Then search for Digital - SW-Timed Output.