Summary of the invention:
The purpose of this utility model provides the telecommunication circuit that a kind of circuit is simple, holding wire is few exactly in order to overcome the above problems, and makes the cost of communication reduce, and design and maintenance are all very simple.
The utility model realizes that the scheme of above-mentioned purpose is: a kind of single line telecommunication circuit, be used for the signal transmission between two or two the above electronic equipments, it comprises transmitting terminal and the sender node that links to each other with transmitting terminal, receiving terminal and the receiving terminal node that links to each other with receiving terminal, and holding wire, it is characterized in that: described holding wire links to each other with receiving terminal node by sender node, and sender node is being communicated with of inhibit signal line and receiving terminal node when the receiving terminal received signal at least.
Adopt the beneficial effect of above scheme: because receiving terminal node and sender node are connected on the same holding wire after being in series, when the receiving terminal received signal, sender node keeps being communicated with, and is equivalent to an adapter.Therefore the utility model only needs a holding wire, just can realize the asynchronous half-duplex serial communication, and circuit is simple, and holding wire is few, makes the cost of communication reduce, and design and maintenance are all very simple.
Embodiment:
Also in conjunction with the accompanying drawings the utility model is described in further detail below by specific embodiment.
As shown in Figure 2, be to be used for two electronic equipments 1 shown in the present embodiment, a kind of single line telecommunication circuit of signal transmission between 2, it is made up of the corresponding mutually telecommunication circuit of two covers, every cover telecommunication circuit comprises transmitting terminal 11,21 (first the cover be 11, second cover is 21, down with) and with transmitting terminal 11,21 sender node 13 that link to each other, 23, receiving terminal 12,22 and with receiving terminal 12,22 receiving terminal nodes 14 that link to each other, 24, and holding wire, described holding wire is by sender node 13,23 with receiving terminal node 14,24 link to each other, sender node 13,23 at least at receiving terminal 12, inhibit signal line and receiving terminal node 14 during 22 received signals, 24 connection--certainly, also can make transmitting terminal 11,21 successively by sender node 13,23 and receiving terminal 12,22 keep and receiving terminal node 14,24 normal opens come to this as shown in Figure 3.
As shown in Figure 2, described sender node 13,23, receiving terminal node 14,24 are made up of isolating converter.Second transmitting terminal 21 makes its node of controlling keep being communicated with when first transmitting terminal 11 sends information, and second receiving terminal 22 is responsible for reception.Make the node of first transmitting terminal 11 keep being communicated with after first complete equipment 1 distributes frame data, first receiving terminal 12 is responsible for receiving data simultaneously.Continuous like this hocketing just can be finished the asynchronous half-duplex serial communication of 2 of first complete equipment 1 and second complete equipments.This structure can also make transmitting apparatus also can receive the signal that oneself has sent on the channel simultaneously, can carry out verification to it easily.
As shown in Figure 3, described four Signal Spacing transducers are made up of light lotus root IC1, IC2, PC1, a PC2 respectively; In device A, holding wire connects the signal input part of the first smooth lotus root IC1 and the signal output part of the second smooth lotus root IC2 by forward diode D1, the signal output part of the first smooth lotus root IC1 meets the first receiving terminal RXD_A, and the signal input part of the second smooth lotus root IC2 meets the first transmitting terminal TXD_A; In equipment B, holding wire connects the signal output part of the 3rd smooth lotus root PC1 and the signal input part of the 4th smooth lotus root PC2 by diode D3, the signal input part of the 3rd smooth lotus root PC1 meets the second transmitting terminal TXD_B, and the signal output part of the 4th smooth lotus root PC2 meets the second receiving terminal RXD_B.Present embodiment adopts the light lotus root to realize isolating conversion, can realize simply isolating and conversion, as between Transistor-Transistor Logic level and the RS232 level even have the equipment of forceful electric power and the conversion of the isolation between the Transistor-Transistor Logic level, make between two communication equipments it can is not also can communicate by letter with a kind of level.Wherein, diode D1, D3, resistance R 3, R8 is the additional protection element, can prevent the infringement that reverse voltage that wiring error or other reasons cause causes the light lotus root.
The utility model also is provided with communication power supply acquiring unit 30, and its input links to each other with civil power, and the power input of the active device in output and the described telecommunication circuit links to each other.Like this, this circuit need not to use independent power supply power supply.