Because the Digi002 and Digi002r does not have wordclock on BNC connectors, the Focusrite OctoPre needs to be the master clock source:
Step 1: Connect the ADAT optical cable from the Output of the OctoPre to the input of the Digi002(R).
Step 2: Set the OctoPre sample rate to 44.1k or 48k.
* Note that because the Digi002 does not support higher sample rates, the OctoPre cannot be set to 88.2k or 96k.
Step 3: Be sure your Pro Tools session and the Digi002 are set to use the same sample rate (44.1k or 48k). This is determined when you create a new Pro Tools session.
Step 4: In ProTools' Setup menu, select hardware setup. In this window, make these two settings:
• Digital Input : RCA=S/PDIF, Optical=ADAT
• Clock Source = ADAT
Step 5: Click OK in the hardware setup window. If the Digi002(R) is locked to the OctoPre as a clock master, the sample rate lights on the Digi002 will have the current sample rate (44.1/ 48) on and NOT blinking.

In ProTools, inputs from the OctoPre will appear as ADAT 1, ADAT 2, etc on the inputs of audio tracks.