| |||
| order wire; engineering speaker circuit; traffic speaker circuit; order-wire | |||
| engineering service circuit | |||
| service circuit | |||
|
circuit de service : 46 phrases in 7 subjects |
| Automated equipment | 1 |
| Communications | 27 |
| Electrical engineering | 2 |
| Electronics | 4 |
| Information technology | 2 |
| Power system protection | 1 |
| Telecommunications | 9 |