Asus TS100-E8-PI4 - Manual (Page 50)

Chapter 3: Motherboard information 3-10
6. Serial General Purpose Input/Output connector (6-1 pin SGPIO1)
The SGPIO 1 connectors are used for the Intel Rapid Storage Technology Enterprise
SGPIO interface that controls the LED pattern generation, device information, and
general purpose data.
7. Serial port connectors (10-1 pin COM2)
These connectors are for the serial COM2 port. Connect the serial port module cable
to one of these connectors, then install the module to a slot opening at the back of the
system chassis.