RME equipment connects like any other digital audio equipment. One should be clock master (e.g. Fireface 800) and one clock slave (OctaMic II). This would be the most convenient setup, as you can change the clock sample rate via software on the host computer. In this case you need a coaxial word clock cable.

Set the DIP switch 1 to WC (lower position). DIP switch 2 has to be also on lower position, as the OctaMic II is clocked from an external master. For a complete follow clock to the external clock you have to set DIP switch 4/5 also to lower position (FC = follow clock).

best regards
Knut

The differences of the DIP switches and the resulting clock behaviour is explained in the manual on pages 13/14.

From the manual:

"With external synchronization active (switch 2 down) and both switches 4 and 5 in lower position, the function Follow Clock (FC) is active. In this case the OctaMic II follows the input clock 1:1. A further configuration of the current sample rate range (Single, Double or Quad Speed) is not required."

If you turn on only switch 5:

"For example if the OctaMic shall operate at 176.4 or 192 kHz, switch 5 has to be set to the lower position. The OctaMic will now generate an output signal in the Quad speed range (176.4 or 192 kHz), even with a word clock input signal of only 44.1 kHz, or an AES input signal of 96 kHz."

best regards
Knut