A 9-pin SUB-D female connector ABIS on the rear panel provides a symmetric (balanced) input of the Abis Interface Unit for CMU (option CMU.B71; for CMU300 only).
The pin assignment is as follows:
Abis Connector
| Pin | Signal | Input (I) / Output (O) / Bidirectional (B) |
Description |
| 1 | – | – | Not connected |
| 2 | – | – | Not connected |
| 3 | – | – | Not connected |
| 4 | – | – | Not connected |
| 5 | ABIS RX | I | Symmetric Abis input |
| 6 | ABIS RX | I | Symmetric Abis input |
| 7 | ABIS TX | O | For future extensions |
| 8 | ABIS TX | O | For future extensions |
| 9 | GND | B | GND |