This document contains the NI-TimeSync known issues that were discovered before and since the release of the NI-TimeSync 17.1. Not every issue known to NI will appear on this list; it is intended to only show the severe and common issues.
Disabling/re-enabling an Ethernet port on a cRIO-903x (Sync) or an IC-317x in NI-MAX or in the command line will cause synchronization issues unless the system is rebooted. Issues might appear as undefined static time offsets, asynchronous FPGA times or the Time Source I/O reporting “None”. Never disable eth0 on the cRIO-9035x (Sync) or eth1 on IC-317x, this will cause all synchronization to halt.
Physically disconnecting and reconnecting an Ethernet cable from a cRIO-903x (Sync) or an IC-317x participating in an IEEE 802.1AS protocol can cause synchronization issues. Devices might not be able to synchronize to each other over an IEEE 802.1AS network. A full power cycle of a device eliminates these issues.
Workaround: It is highly recommended to always power cycle controllers anytime physically reconfiguring Ethernet cabling.