ITC/USA 2014 Conference Proceedings / The Fiftieth Annual International Telemetering Conference and Technical Exhibition / October 20-23, 2014 / Town and Country Resort & Convention Center, San Diego, CA / Ethernet-based data acquisition systems are becoming more and more common in the Flight Test Instrumentation environment. Digitized analog sensor output and various other types of digital data is captured and inserted into Ethernet packets using a "packet fill" strategy that in general is under control of the user. This paper discuss and compares two strategies "FILL-TO-TIME" and "FILL-TO- SIZE" for the acquisition of ARINC-429 digital data bus.