Asus RS500A-X6 PS4 User Manual page 57

9. Power supply SMBus connector (5-pin PSUSMB1)
This connector is for the power supply SMB cable, if your power supply
supports the SMBus function.
10. Baseboard Management Controller (BMC) connector (14-pin BMC_FW1)
This is an interface used to plug in an ASMB4-SOL or ASMB4-iKVM
management device.
The ASMB4 management device is purchased separately.
ASUS RS520-E6/ERS8 4-13