PURPOSE: To always monitor the discontinuation of the transmitting function and also to reduce the power consumption with a transmission system, by transmitting with relay only the transmitting function check signal that is extremely short in terms of time via each transmitter and transmitting the information data from each transmitter only when the information to be transmitted has a change.
CONSTITUTION: If an optical fiber 1 connecting both transmitters 3 and 4 is cut by some reason, a check signal P sent from the transmitter 3 never reaches the transmitter 4. Therefore the transmitter 4 is unable to receive the signal P even at a time point t3 when a timer counted time τ. Thus an abnormality signal SE is produced and transmitted to a data collector 6 via a transmitter 5. Then the collector 6 detects the abnormality of the transmitting function. In case the data D4 supplied to the transmitter 4 has a change as shown at a time point t4, the new data D4 is sent instantaneously to the collector 6 via the transmitter 5.
IMAI YASUMASA
KASHIMURA TOSHIYASU
| JPS59212050A | 1984-11-30 | |||
| JPS58123255A | 1983-07-22 | |||
| JPS57157662A | 1982-09-29 | |||
| JPS5481702A | 1979-06-29 |