I have an Elite 192 that I had a local shop program for me. I use three of the buttons on a DTU-16 to dial an outside line. We have three CO lines but the third one is for future and has no dial tone (CO) connected. When I select one of those three buttons it will try to dial that number on CO3. Where in the SAT can I change that to dial on CO1 first?

Also is there a description of what the memory blocks 9-4-01, 9-4-02 and 9-4-03 are? The manuals I have do not go that far.

Sounds like your first three buttons have been programmed for auto route selection, call your local shop back to re-program the system to fit your needs using auto route selection or not.

Memory block 3-03, Trunk Group Assignment. Simply put CO line 3 in trunk group 00 until you add it later.

Thats Right MB-3-03,you won't be able to have it grab co-1 first, it starts from your last line working up to co-1. (keeps you from grabbing an incomming call when trying to dial out.

That was the trick. It makes sense that it chooses from last to first. Since we only have one line for general use it has no other choice, lol.