Attachment unit interface
An Attachment Unit Interface ( AUI ) is an electrical and mechanical interface for the physical separation of a Medium Attachment Unit (MAU) ( transceiver ) and an Ethernet controller ( Media Access Control (MAC)). It is part of the Ethernet standard according to the guidelines of the Institute of Electrical and Electronics Engineers (IEEE).
The AUI has a 15-pin D-Sub connector that is attached with clamps instead of screws. The cable of an AUI can be up to 50 meters long, but the two elements MAU and MAC are often also directly connected.
development
In the course of the early 1990s, the AUI connections became increasingly rare as the MAU was increasingly integrated directly into the computer and the hub . The reason was that the 10BASE-T standard prevailed and the use of the older 10BASE5 (Thick Ethernet) and 10BASE2 (Thin Ethernet) declined. However, the AUI electrical connection was still contained within the device. Use continued to decline from the mid-1990s, and the AUIs have almost completely disappeared with Fast Ethernet . This had an equivalent in the Media Independent Interface (MII). The following Gigabit Ethernet and 10 Gigabit Ethernet have the standards provided by the Gigabit Interface Converter (GBIC) and the Extended Attachment Unit Interface (XAUI), which are equivalent to the AUI.
Apple Macintosh
In the Apple Macintosh computers , a modified and smaller version of the AUI, the Apple Attachment Unit Interface (AAUI), was used in the early 1990s because the monitor connection common at the time on the Macintosh had the same shape and number of pins (DB- 15).
Occupancy
The pin assignment of the AUI looks like this:
 View of the connector. |
||
|---|---|---|
| Pin code | Circuit | description |
| 3 | DO-A | Data Out Circuit A. |
| 10 | DO-B | Data Out Circuit B |
| 11 | DOS | Data Out Circuit Shield (not used) |
| 5 | SLIDE | Data In Circuit A. |
| 12 | DI-B | Data In Circuit B |
| 4th | DI-S | Data In Circuit Shield |
| 7th | CO-A | Control Out Circuit A (not used) |
| 15th | CO-B | Control Out Circuit B (not used) |
| 8th | CO-S | Control Out Circuit Shield (not used) |
| 2 | CI-A | Control In Circuit A. |
| 9 | CI-B | Control In Circuit B |
| 1 | CI-S | Control In Circuit Shield |
| 6th | VC | Voltage Common |
| 13 | VP | Voltage plus |
| 14th | VS | Voltage shield (not used) |
| Shell | PG | Protective Ground |
