| 摘要 |
<p>PURPOSE:To reduce the cost because of reduction of number of lines, to make the size small and to improve the reliability through the reduction of number of components by detecting a line abnormality only in a transmission line through which data are sent. CONSTITUTION:A sender side equipment is provided with a DC power supply and one transmission element 1 turning on/off a DC current of the DC power supply to send digital information, and a receiver side equipment opposite to the sender side is provided with a 1st reception element 2 connected between the DC power supply and the transmission element 1 as a closed circuit and detecting an ON/OFF signal of the transmission element 1 and a means sending information representing whether or not the 1st reception element 2 receives the signal normally to the sender side equipment. A 2nd reception element 3 as the means for sending information is inserted in the closed circuit of the sender side equipment.</p> |
