Option 118 uses FIFO (first-in first-out) to allow external point- trigger acquisition of 400,000 data points per second on five measurement receivers. When enabled, there is no display update, no background computation, or other interference from the vector network analyzer application. All the data gathered is placed into a 500 million points FIFO buffer. While the data is going into FIFO it can be read from the FIFO buffer.