Yesterday, I quoth: > Possibly some of this is related to the weird linked-but-not-linked behaviour > when the backup link is connected but unneeded (described in my prior email).
Well, I've fixed that now (it was an incorrect assumption in the EtherCAT driver mods), but it hasn't helped the delay measurements. I guess the main problem is that the measurement code seems to assume that the receive timestamps are all updated from the same packet. But in a redundant topology, especially with no network breaks, some of the ports don't actually receive packets, or the timestamps within a single slave are updated from different packets traversing. So a port might be "open" but the timestamp may not have updated or may be from a packet sent at a different time from what you're expecting. And the topology calculations assume that the packet is always entering from port 0, which isn't always true with a redundant setup. (I can understand why -- I've had a think about it and it's quite a tricky problem, especially given some of the limitations on data available from the slaves.) _______________________________________________ etherlab-users mailing list etherlab-users@etherlab.org http://lists.etherlab.org/mailman/listinfo/etherlab-users