Parameters
| Power supply | Mains power: AC 220V (+10%, -15%, 50Hz) Standby power supply: External DC24V |
| Bus current | ≤600mA |
| Frequency range | 300~3400Hz |
| Transmission attenuation | ≤5dB |
| Recording duration | more than 20min |
| Length of bus | ≤1,500m |
| Weight | ≤10kg |
| Dimensions | 406×331×174(mm) |
| Working environment | Temperature 0~+40ºC, RH ≤95% |
| Bus capacity | up to 99 code addresses (set by code switch in binary mode) |
| The host supports communication with at most 3 extensions simultaneously | |
| Support up to query and playing 99 segments of recording | |
| At most 120 call messages can be recorded | |
| Line condition | extension loop resistance (exclusive of phone resistance) ≤ 300 Ω |




