Need to write and read with serial communication

Hello all,

I am communicating with digital I/O card through serial communication which is having 8 output and 8 input channels.

I need to use input and output channel at a time. my scenerio is to first i have to set the output channels and get the input channels status in same port but both I/O channel will give different output. i need to store it.

can you give me a idea how can i write two commands and read the data separately for those write commands at a time ? 

Thanks in advance