Figure F19. Example showing the results of the time difference measurement of the precision real-time clock (RTC) in the multiple-access expandable gateway (MEG) and the storage acquisition module (SAM). The offset of the RTC in the SAM-191 to the Global Positioning System (GPS) was measured and reported by the combiner/repeater module processor. The time difference between the RTC in the MEG-191 and that in the SAM-191 was also plotted. The time difference is measured using stream sync in a serial line.