Yep, the retaining screw is in and I swapped the uni board in slot 1 that had the 2 DLMs and the SLM modules and moved it to slot 2 with the 4trm installed with no change, and all 4 ports are being used.
feeding the single lines into the co ports is a good idea, when I bring the compact to the site on Monday I'll take the 7100 out of service with just 1 28 button falcon set connected and feed the 4 single lines in and see what happens.
The thing that gets me is that I had it on the bench for a day before the install but with just 1 CO line connected and I didn't see anything funky going on.
Days like this make me wish I joined the circus
