Logical zones grouped by device function for D-305. Physical detection-zone boundaries (Clause 13) are defined on the as-designed drawing.
| Optical Smoke | 46 |
| Multi-sensor | 8 |
| Zone total | 54 |
| Manual Call Point | 8 |
| Zone total | 8 |
| Sounder + VAD | 14 |
| Zone total | 14 |
| I/O Interface | 4 |
| Zone total | 4 |