Qualification of One and Two Interconnects in a Spacewire Link

NRL has validated non-standard cabling previously as documented in a paper for the 2008 International SpaceWire conference and applied that knowledge to qualify a new set of non-standard cables. NRL built three four-meter long test cables with zero, one and two series 79 connector pairs inline. These cables were subjected to a test campaign over temperature including time domain reflectometry, insertion loss measurement, bit error rate testing, link rate testing and eye diagram analysis. The test campaign, test equipment and pass/fail criteria are provided as a notional qualification procedure for future non-standard cables. All test results in all test configurations passed at 200Mbps with significant margin. The test results show an expected trend in that the cable with no connections is better than one in-line connection cable which is better than the cable with two inline connections. There was a slight trend in results over temperature in that results at hot temperature are better than test results at ambient temperature which is better than results at cold. The effects are much less impactful than expected in that no measurement deviated more than fifteen percent across all configurations, and all temperatures.