How to send a trigger signal to these two hardware?

Hi experts,
I have different hardwares and to start, my hardwares are -PXI 1044-PXI 8106-PXI 5142 (Digitizer)-PXI 5441 (AWG) that will help you to understand what I really need to do and what more hardware will be needing. To send commands, I am using the serial port to external hardware.
At the same time I have to generate a signal with the AWG and to run an acquisition on the digitizer. I am not a genius about hardwares, that's why I really needed help.
