Asus RS720-E7/RS12-E - Hard Disk Activity LED Connector (4-Pin HDLED1); USB Connectors (10-1 Pin USB34, USB56; A-Type USB10)

ASUS RS720-E7/RS12; RS720-E7/RS12-E 4-9
3. USB connectors (10-1 pin USB34, USB56; A-Type USB10)
These connectors are for USB 2.0 ports. Connect the USB module cables to
connectors USB34 and USB56, then install the modules to a slot opening at
the back of the system chassis. These USB connectors comply with USB 2.0
specication that supports up to 480 Mbps connection speed.
4. Hard disk activity LED connector (4-pin HDLED1)
This LED connector is for the storage add-on card cable connected to
the SATA or SAS add-on card. The read or write activities of any device
connected to the SATA or SAS add-on card causes the front panel LED to
light up.