DAC8742HEVM: how to check HART module dection?

Naresh, 

How do you have the DAC8742EVM set up? I assume that you have the input coming in through J7 on the board. If a HART sinusoid appears on the line, the CD pin should go high to indicate the carrier is detected. You should also see the UART signal appear as a result. With an oscilloscope, it would look a little like this:

Note that the DAC8742H uses a 16-byte FIFO buffer, so there is a limit to how much data that can be read at a time. In general, you won't be able to read an entire HART command because of the length of the message. 

Joseph Wu