when i select 'out' it doesnt have adat choice..???
You won't see anything about ADAT in the Output pulldown menu. Just Tape Outputs 1-24. These represent the pathways to the OPT8 card optical outputs.
If you want to get the D8B to feed DP7 and you have the #1 OPT8 card connected to an MPC (at least that's what it sounds like you've done) then you have to use Tape Outputs 9 thru 24 to get into DP7. You'd use Tape Outputs 1-8 to get in and out of the MPC.
Additionally, if you want to mix a number of tracks to a particular Tape Output, you have to assign those channels to a Bus (one or more of the green buttons above the LR button) and send the Bus (last 8 slots on the Masters Deck) to Tape Outputs 1-8 (MPC) and 9-24 (DP7). When you assign input channels to tape outputs (or busses to tape outputs), be sure and turn off the LR bus assignment for those input channels, otherwise you'll get "double monitoring" from the returning Tape In channels.
Conversely, the returns from the MPC and DP7 will show up on the Tape In Deck. The MPC will show up on channels 25-32 while the DP7 will show up on channels 33-48.
As to dealing with "double monitoring", this next idea goes a bit deeper: during tracking, you can leave the LR assigns on, provided DP7 is capable of providing a "manual monitor" or "tape monitor" emulation function. The concept is that DP7 records the inputs coming from the D8B but doesn't pass those live signals to the DP7's outputs (and back to the D8B) until you Stop/exit Record or Play on DP7.
I can't help you with setting up DP7 beyond suggesting to make sure it's expecting D8B inputs from ADAT 9-16 and 17-24 and sending its outputs to ADAT 1-8 (for the MPC) and ADAT 9-16/ADAT 17-24 (for the D8B).