| 摘要 |
<p>PROBLEM TO BE SOLVED: To enable a relay device to provide an upper-level device with information including the state of an analog dedicated line through an ISDN circuit.SOLUTION: A relay device includes: a relay device-side voice transmitter unit 51; and a relay device-side voice receiver unit 52. The relay device-side voice transmitter unit 51 transmits, to a lower-level device 17, a remote control signal and a voice signal. The relay device-side voice receiver unit 52 receives a remote control signal and a voice signal from the low-level device 17, to transfer, through an ISDN line 3, data composed of a synchronous signal, the remote control signal and the voice signal through the upper-level device 13 to a control console 11. Among signals included in the remote control signal, which are incapable of thinning and capable of thinning, the signal capable of thinning is replaced by information in which the state of an analog dedicated line 5 is included, so as to transmit according to the synchronous signal.</p> |
