What is AUI(Attachment Unit Interface)?

AUI stands for Attachment Unit Interface. AUI is a portion of Ethernet standards that specifies how a cable is going to connect to an Ethernet card. AUI is a physical and logical interface. AUI is defined in IEEE 802.3 standard for 10BASE5 Ethernet. AUI connector is a 15 port connector that provides a path between an Ethernet node’s Physical Signaling and the Medium Attachment Unit (MAU).

S.No.	Signal	Description
1	CI-S	Control In Circuit Shield
2	CI-A	Control In Circuit A
3	DO-A	Data Out Circuit A
4	DI-S	Data In Circuit Shield
5	DI-A	Data In Circuit A
6	VC	Voltage Common (0 V)
7	CO-A	Control Out Circuit A (not used)
8	CO-S	Control Out Circuit Shield (not used)
9	CI-B	Control In Circuit B
10	DO-B	Data Out Circuit B
11	DO-S	Data Out Circuit Shield (not used)
12	DI-B	Data In Circuit B
13	VP	Voltage Plus (+12 V)
14	VS	Voltage Shield (not used)
15	CO-B	Control Out Circuit B (not used)
Shell	PG	Protective Ground