Have a look at v_out.py and ULAO01.py. These two examples will work with your device. Outputs can be set with either the v_out or the a_out function. The v_out function takes floats for data and a_out an integer.
data_value = 3.0
channel = 0
ul.v_out(board_num, channel, ULRange.UNI10VOLTS, data_value, 0)
You could use a_out_scan, but the rate cannot exceed 100 divided by the number of scanned channels. Underneath, it uses a_out to update the channels. However, it has a SIMULTANEOUS scan option that can be used to update all the channels simultaneously.
