| Share | Phrase |
|---|
| 33.14% | bi-directional [direction] bus |
| 22.43% | bi-directional [direction] motor |
| 15.29% | bi-directional [direction] pump |
| 6.48% | bi-directional [direction] wire |
| 6.16% | bi-directional [direction] device |
| 5.04% | bi-directional [direction] windlass |
| 4.62% | bi-directional [direction] path |
| 3.52% | bi-directional [direction] position |
| 3.28% | bi-directional [direction] system |