Matt Weaver (timing expert) says it's actually fine to configure systems in slots 3-7 in fiber timing mode, and that they'll automatically know that since they're not in slot 2 they can't distribute the signal over the backplane. I'll change this to a soft warning and allow fiber timing configuration.
I was too restrictive in a recent PR here;
https://github.com/slaclab/pysmurf/blob/9109a89e91f5e5e46404ab8b2fc7f6b1c1a66b59/python/pysmurf/client/util/smurf_util.py#L4762
Matt Weaver (timing expert) says it's actually fine to configure systems in slots 3-7 in fiber timing mode, and that they'll automatically know that since they're not in slot 2 they can't distribute the signal over the backplane. I'll change this to a soft warning and allow fiber timing configuration.