JPS59122260A - Transmitting system of data - Google Patents

Abstract

PURPOSE:To transmit data on a line between prescribed stations by optical communication without changing the hardware and software of the stations and to make the mixing of data transmission possible by the signals of electric and optical systems, by applying optical communication to a multi-drop type transmission system. CONSTITUTION:A signal from another station is received by an optical receiver 21 and transmitted to one station through gates 43, 45, 44 and an electric system driver 13. The signal from the station is transmitted to another optical bus through an electric system receiver 12, gates 41, 45, 42 and a transmitter 22 to communicate with another transmitter. A first arrival discriminating circuit 30 discriminates which receiver out of the optical receiver 21 and the electric system receiver 12 has received the signal first and controls the gates 41-44 to set up a faster transmission course.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a new data transmission system that applies optical communication to a multi-drop transmission system and performs data transmission between one system and another by optical communication.

[Technical background of the invention and its problems]

Conventionally, when transmitting data between stations using optical communication, the ring system is often used. 1st
The figure is a configuration example diagram of a ring/mass type data transmission system. In this data transmission system, as shown in FIG. 1, stations S to S4 are connected in a shilling shape by optical fiber transmission lines to transmit data.

However, in such a ring/mass type data transmission system, for example, as in the data transmission system of an instrumentation system, there is a possibility that a failure of one station will stop the data transmission function of other stations. For this reason, when such a transmission outage has a large impact on others, a multi-drop data transmission system is often used. FIG. 2 is a diagram showing an example of the configuration of a multi-drop type data transmission system. This data transmission system consists of stations S5 to S5 as shown in FIG.
Sn is connected by -a through an electrical transmission line E. If optical communication technology is adopted for this multi-drop data transmission system due to the advantages of optical communication technology, it is necessary to use advanced technologies such as optical splitters or star cables, and these optical communication devices are As the number of installations increases, a large number of them are installed, which increases the cost and also increases the amount of attenuation of optical communication signals.

Another drawback is that it is essentially impossible to transmit electrical signals and optical signals together.

[Purpose of the invention]

In order to eliminate the above-mentioned drawbacks, the present invention performs data transmission on required inter-station lines by optical communication without changing the hardware and software of the stations of a multi-drop data transmission system, and also connects electrical systems. It is an object of the present invention to provide a data transmission system that can perform mixed data transmission with an optical system.

[Summary of the invention]

The present invention provides an air-to-optical mutual conversion means in required lines between stations in a multi-drop transmission system, and uses this electric-to-optical mutual conversion means to convert electrical signals from the station and signals from the station other than the station. A first-arrival determination circuit determines whether either the optical signal from the station or the converted electrical signal was input first, and based on the first-arrival signal from the first-arrival determination circuit, the electric signal arrives first. The electrical signal is sent to the optical system transmitting/receiving section by the branching means, and when the electrical signal converted from the optical signal arrives first, this electrical signal is sent to the electrical system transmitting/receiving section through the branching circuit. It is a data transmission system that converts received electrical signals and optical signals into optical signals and electrical signals, respectively, and outputs the signals.

[Embodiments of the invention]

The first embodiment of the present invention will be explained below with reference to FIGS.
a) Explain with reference to (b). Note that the same parts as in FIG. 2 are given the same reference numerals and detailed explanations will be omitted. Third
The figure is a configuration diagram of a data transmission system according to the present invention.

In this data transmission system, an electric-to-optical mutual converter ELT and an optical fiber transmission line are provided in the electric transmission line E of the multi-drop-shaped data transmission system shown in FIG.

FIG. 4 is a block diagram of the electric-optical mutual converter ELT. This electrical-optical mutual converter ELT includes an electrical system transmitting/receiving section 10. Optical system transmitter/receiver 20, first-come-first-served determination circuit 30. It is composed of a branch circuit 4θ, a waveform shaper 50, and an oscillator 60. The electrical transmitter/receiver 10 receives an electrical signal from, for example, a coaxial cable via a pulse transformer 11 with an electrical receiver 12 and sends it to the first-come-first-served determination circuit 30 and the branch circuit 40 , and the optical transmitter/receiver 20 The optical signal is converted into an electrical signal and is outputted from the electrical system driver 13 via the pulse transformer 11. The optical system transmitting/receiving section 20 receives an optical signal from the optical fiber transmission path through the optical receiver 21 and transmits it to the first-arrival determination circuit 30 and the branch circuit 40, and the electrical signal received at the electrical system transmitting/receiving section 10 undergoes waveform shaping. The signal whose waveform is shaped by the optical fiber transmission line 50 is converted into an optical signal by the optical transmitter 22 and sent to the optical fiber transmission line. The first-come-first-serve determination circuit 30 is
The flip-flop circuit determines which of the signals from the electrical system and optical system transmitter/receiver 70°20 was input first.
It is composed of a loop and a logic circuit, and outputs first-come-first-served signals for the electrical system and optical system based on the previously input signal. The branch circuit 40 is as shown in FIG.

When the electrical system first-arrival signal -μ is input, the electrical system transmitter/receiver 10
The signal is sent to the optical system transmitter/receiver 2 via the waveform shaper 50.
0, and when the optical system first-arrival signal 2 → 7 is input, the signal from the optical system transmitting/receiving section 20 is sent to the electrical system transmitting/receiving section 10 via the waveform shaper 50.
It is composed of NDR gates 41-44 and an OR gate 45. The waveform shaper 50 is composed of a flip-flop and a dart circuit, and transmits/receives the electric system and the optical system.
These signals are shaped into distortion-free signals based on the signal from the oscillator 60. The oscillator 60 sends a constant frequency signal to the first-come-first-served determination circuit 30 and the waveform shaper 50 to stabilize the operation.

Next, the operation of the system configured as above will be explained. First, the case of converting an electrical signal into an optical signal and outputting it will be explained. The coaxial cable full-color electric signal is received by the electric receiver 12 via the transformer 1, and is converted into the required logic level by the electric receiver 12 to produce a signal as shown in FIG. 5(a). A1 is sent to the first-arrival determination circuit 30 and the branch circuit 4o.

At this time, no optical signal is input to the optical system transmitting/receiving section 2o because of half-duplex transmission of electrical signals and optical signals. Therefore, the first-arrival determination circuit 3o outputs the electrical first-arrival signal A2 of "1" shown in FIG. 5(,) to the AND gates 41 and 42. Thus, the AND gate 4 is in the ON state, and the signal A1 from the electrical transmitting/receiving section 10 is sent to the waveform shaper 50 via the OR gate 45. This shaped signal is A
The signal A shown in FIG.
The signal is sent to a third optical transmitter 22, where it is converted into an optical signal, and an optical signal corresponding to the electrical signal is output to an optical fiber transmission line.

Next, the operation of converting an optical signal into an electrical signal will be explained. The optical signal from the optical fiber transmission path is received by the optical receiver 2, which converts it into a logic signal B1 corresponding to the optical signal, and sends it to the first-come-first-served determination circuit 30 and the AN.
It is sent to D port 9-43. At this point, as in the case where the electrical signal is received as described above, the electrical signal is not being manually transmitted due to half-duplexing. Accordingly, first arrival determination circuit 30il-i: AND r-to4 with optical system first arrival signal B2.
,? , output to 44. This is useless AND r”
The logic signal B7 from the SIB C receiver 21 with the gate 43 in the ON state is transmitted to the waveform shaper 50 via the OR'f'' gate 45.
After being sent to and subjected to waveform shaping, AND key 4-q
The signal B3 shown in FIG. 5(b) is then sent to the electrical driver 13.

As a result, a signal converted into an electrical signal is outputted via the pulse transformer 1.

The above-mentioned electrical-optical conversion is performed, and for example, the electrical signal from station S5 shown in FIG. The optical signal is sent to ELT 2, which converts the optical signal into an electrical signal, thereby sending the data from station s5 to station S6.

Data transmission in a multi-drawer F-type data transmission system is performed by providing a no-signal state for a predetermined period of time between a transmission frame and the next transmission frame.

According to the system configured in this manner, an electric-to-optical mutual converter ELT is provided between stations S5 and SnO of the multi-drop data transmission system, and this converter ELT
Since the data is transmitted by converting the optical signal into an optical signal and the optical signal into an electrical signal, data can be transmitted without changing the hardware or liftware of station 795 to Sn in a multi-drop data transmission system. can be transmitted.

Furthermore, this system can be easily implemented without using advanced technology such as an optical splitter or star canola, and without being expensive.

Furthermore, since the first arrival determination circuit 30 is provided, the signal output from the electrical system driver 13 is transmitted to the pulse transformer 11.
Even if a part of the signal appears in the stain air system receiver 12 due to the induction effect of this signal or the system transformer 1 and is sent to the first-arrival determination circuit 30, this signal is different from the signal from the optical receiver 21. Since the signal is also input with a delay, the electrical system first-arrival signal Bl is never output.

Next, second and third embodiments of the present invention will be described. FIGS. 6 and 7 are configuration diagrams of second and third embodiments of this system. The system shown in FIG. 6 includes an electric-optical mutual converter E between stations S5 and 86.
LT5.

An ELT 6 is provided to partially transmit data through optical communication.This system shown in FIG.
Optical mutual converters ELT7 and ELT8 are provided for data transmission.

In this way, in the second and third embodiments, data can be transmitted by optical communication without changing the hardware and software of the stations 85 to Sn, as in the first embodiment. In addition, optical communication is resistant to electricity and electrical noise, so optical fiber transmission lines can be used for transmission lines installed outdoors to prevent the effects of lightning and electrical noise, especially devices that use high voltage such as CRTs. This can increase safety by preventing the effects of

[Effects of the Invention] According to the present invention, an electrical-to-optical mutual converter is provided in the required transmission line between stations of a multi-drop data transmission system to transmit data by optical communication, so that the hardware and software of the stations are reduced. It is possible to provide a data transmission system that can perform data transmission on required inter-station lines by optical communication without changing the data transmission system, and can also perform duplex data transmission using electrical and optical system signals. .

[Brief explanation of drawings]

Fig. 1 is a block diagram of a data transmission system using a ring bus method, Fig. 2 is a block diagram of a conventional data transmission system using a multi-drop type, and Fig. 3 shows a first embodiment of a data transmission system according to the present invention. Fig. 4 is a block diagram of the electrical-to-optical mutual converter in this system;
The figure is a configuration diagram showing the second and third embodiments of this system. lO... Electrical system transmitting/receiving section, 1 No./f Lust transformer, 12... Electrical system register, etc., 13... Electrical system driver, 20... Optical system transmitting/receiving section, 2 No. ... Optical receiver, 22... Optical transmitter 1, 90... First-come-first-served judgment circuit, 40... Branch circuit, 41-44... AN
D dart, 45... OR gate, 50... waveform shaper, 60... oscillator.

Claims (2)

[Claims] (1) In a data transmission system in which data is transmitted between systems using a multi-drop transmission system, an electrical signal from the station is transferred to an optical signal on an IJ transmission line between the stations. 1. A data transmission system comprising electrical-optical mutual conversion means for converting into electrical signals. (2) The electrical-optical interconverting means receives the electrical signal from the station, and converts the optical signal from the electrical-optical interconverting means provided in a pair with the electrical-optical interconverting means into an electrical signal. an electrical transmitter/receiver that outputs the converted signal; and an electrical-optical mutual converter that converts the optical signal from the pair of electrical-optical mutual converters into an electrical signal, and receives the electrical signal at the electrical transmitter/receiver. The optical fiber sending/receiving section converts electrical signals into optical signals and outputs them, and compares and determines the input arrival time of each signal from the electrical system and optical system transmitting/receiving section, and determines the first-arrival signal according to the signal that arrived first. a first-arrival determination circuit that outputs a first-arrival determination circuit; and a signal from the electrical transmission/reception section to the optical transmission/reception section based on the first arrival signal from the first-arrival determination circuit; and a signal from the optical transmission/reception section to the electrical transmission/reception section. Claim 1, characterized in that the device comprises a branching means for branching, and a waveform shaper for shaping signals from the electrical system and optical system transmitting/receiving section in the branching process of the branching means. data transmission system.