Analog Signal Timing and Logging

[CaseyM]

Suppose I have two signals - A and B. I want to output signal A followed by some user defined delay and then output signal B on two separate AO channels. This process can be automated to repeat N number of times. Now also suppose that I'm reading an AI channel continuously, but I only want to log data from that analog input when B is being output. How can I trigger logging when B starts? (This needs to be hardware timed so no data is skipped so occurrences and other such software features are out.)