327953.fig.002a
(a)
327953.fig.002b
(b)
Figure 2: Measuring the data-access delay in real time. (a) Red pulses correspond to the signal created by the acquisition workstation; blue traces show the time when the computer reading from the Fieldtrip buffer detected the pulse and sent an acknowledgment pulse back to the acquisition computer. The delay was measured by calculating the time difference between all vertical red bars and the corresponding blue bars. (b) Histogram of the observed delays during a 5-minute measurement with buffer size 29.