...

The XPM may be instructed to require a transition to obey deadtime by including bit 7 (OR 1<<7) when writing to the "MsgHeader" PV.  Ordinarily, just the TransitionId is written to this PV.  As it currently stands, transitions do not obey "coupled deadtime".  They only respect the deadtime of each group.

Opal

NOTE: when setting up an opal, the LCLS2 timing comes in on lane 1 (counting from zero) on the second QSFP, as described here:  https://github.com/slaclab/cameralink-gateway.

...