The attached plot shows the uptime for all three EtherCAT computers. A restart is occurring, when the value jumps to zero from a value smaller than 49.7 days. If it reaches 49.7 days (2^32 in ms), it simply wraps around back to zero. Most of the restarts were due to software upgrades. The only 2 crashes in the past 64 days were in end X due to a now fixed configuration error. End Y has been up and running for more than 50 days without interruption.