Accusys ExaSAN A12S2-PS - Manual (Page 16)

2. Insert the other end of the cable into the PCIe port on the HBA card,
which you installed on the host system in the earlier section. The cable
connector is securely plugged when you hear a click.
3. Plug a power cord into the AC power-in port in the storage system.
Caution
Once powered on, Do NOT remove the QSFP PCIe cable when in
use to avoid data loss and corruption.
Quick Start Guide
P12