Anbu,
[quote user="Anbazhagan Sakthivel"]1.Can the LDAC be tied to ground at first, before powering device.[/quote]
Yes, /LDAC can be tied to ground during power on. If kept low after power on, the output of the DACs will be updated on the rising edge of /CS .
[quote user="Anbazhagan Sakthivel"]2.For unipolar operation S1 should be on side 4 or 5. [/quote]
Group A will be uni-polar while on S1[5].
Group B will be uni-polar while on S1[7].
[quote user="Anbazhagan Sakthivel"]I can see the trace of my SPI, as expected by the DAC. So there is no problem with input. But still after following all these things, the output is just 0.244V irrespective of my change in input. What does that mean?[/quote]
The 0.244V may be due to a floating reference. It may also mean that one of the power inputs is not being applied.
Probe TP1 in order to make sure that there is no issue with the reference. Double check J3, to make sure that all of the voltages are being supplied.
If you can share a scope capture of your digital inputs I can also make sure that there isn't an issue there.