JPH06141050A - Optical transceiver - Google Patents

Abstract

PURPOSE:To provide an optical-transceiver capable of taking out the reception signals of a priority channel when optical signals are simultaneously received and constructing a duplex network. CONSTITUTION:This optical-transceiver is provided with light transmitters 1 and 3, light receivers 11 and 13, a selection circuit 5 and an electric input/ output interface 7. The light transmitters 1 and 3 simultaneously transmit one kind of signals, the light receivers 11 and 13 respectively receive the plural optical signals and the selection circuit 5 is composed of plural signal detection circuits 51 and 52 and a channel switching circuit 53. When the optical signals are received at the light receivers 11 and 13, at the signal detection circuits 51 and 52, the presence of the respective reception signals is detected and when it is detected, detection signals corresponding to the duration of the reception signals are outputted. Also, the channel switching circuit 53 which received the detection signals selects the priority channel of the reception signals from the respective light receivers 11 and 13 corresponding to the respective detection signals based on a prescribed channel priority order.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical transceiver used for an optical fiber data link, and more particularly to an optical transceiver capable of extracting a received signal of a channel having a high priority when receiving light at the same time.

[0002]

2. Description of the Related Art Conventionally, this type of optical transceiver has been used for, for example, an optical fiber data link, and converts an electric signal into light and sends it to an optical fiber transmission line.
It is provided as a device for converting an optical signal transmitted through an optical fiber transmission line into an electric signal.

FIG. 2 is a block diagram showing a conventional optical transceiver. In this figure, the optical transceiver includes two optical transmitters 101 and 103 for transmitting optical signals to two terminal stations (not shown), an OR circuit 105 for ORing two input electric signals, and an OR circuit. The electric signal from 105 is input, and the two optical transmitters 101,
It is composed of an electric input / output interface 107 for supplying an electric signal to 103, and two optical receivers 111, 113 for respectively receiving optical signals from two terminal stations (not shown).

According to such an optical transceiver, the transmission signal output from the electrical input / output interface 107 is given to the optical transmitter 101 and the optical receiver 103.
The optical signals converted from the electrical signals by the optical transmitter 101 and the optical receiver 103 are simultaneously transmitted to two terminal stations (not shown) through the optical fiber.

On the other hand, the optical signals respectively transmitted from two terminal stations (not shown) are transmitted through the optical fiber and are respectively received by the optical receiver 111 and the optical receiver 113. The optical signals received by the optical receiver 111 and the optical receiver 113 are converted into electrical signals and then OR'ed by the OR circuit 105. The electrical signal logically ORed by the OR circuit 105 is input to the electrical input / output interface 107.

As a result, a tree-type local area network (hereinafter referred to as "LAN") between the local station and a plurality of terminal stations is provided.
Is abbreviated. ) Was formed.

[0007]

According to this conventional optical transceiver, the signals respectively received by the optical receiver 111 and the optical receiver 113 are input to the OR circuit 105. Therefore, the optical receiver 111 and the optical receiver 11
When the optical signals 3 and 3 are received at the same time, the received signals collide with each other, so that the two received signals are combined and output to the electrical input / output interface 107. Therefore,
Such a conventional optical transceiver has a drawback that a transmission error occurs.

On the other hand, in consideration of network duplication, two systems of an optical receiver 111 and an optical receiver 113 are simultaneously connected to one terminal station and two optical transmitters of other stations. In this case, signal collision always occurs, and as a result, there is a drawback that duplication cannot be performed.

Therefore, an object of the present invention is to provide an optical transceiver capable of extracting a reception signal of a priority channel and constructing a duplex network when receiving optical signals at the same time.

[0010]

In order to achieve this object, an optical transceiver according to the present invention comprises a plurality of optical transmitters for simultaneously transmitting one type of signal by a plurality of optical transmitters, and a plurality of optical signals. In an optical transceiver equipped with a plurality of optical receivers for receiving each, each output signal from the plurality of optical receivers is captured, the presence or absence of each output signal is detected, and a detection signal corresponding to the duration of the received signal is detected. On the basis of this, a selection circuit capable of selecting one of the output signals according to a predetermined channel priority is provided.

Here, the selection circuit outputs a detection signal corresponding to the duration of the reception signal when detecting the presence or absence of each reception signal from each optical receiver, and a predetermined signal detection circuit. A channel switching circuit that selects the priority channel of the received signal from each optical receiver according to the above-mentioned detection signals based on the channel priority order may be provided.

According to the present invention, a plurality of signal detection circuits for outputting a detection signal corresponding to the duration of the reception signal when the presence or absence of each reception signal from each optical receiver is detected, and a predetermined channel priority order. Based on the detection circuit provided with a selection circuit consisting of a channel switching circuit for selecting the priority channel of the received signal from each optical receiver according to each detection signal, even when the optical signals are simultaneously received by a plurality of optical receivers, The reception signal of the priority optical receiver can be extracted normally, and even if multiple optical receivers are receiving optical signals at the same time, even if a failure occurs in one system, the selection circuit automatically selects another The reception can be switched to the system of.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the optical transceiver of the present invention. Referring to this figure, the optical transceiver is composed of two optical transmitters 1 and 3, a selection circuit 5, an electric input / output interface 7, and two optical receivers 11 and 13.

Here, the two optical transmitters 1 and 3 are connected to the electrical input / output interface 7. Further, the two optical receivers 11 and 13 are connected to the electric input / output interface 7 via the selection circuit 5.

The selection circuit 5 includes two signal detection circuits 51,
52 and one channel switching circuit 53. The output signals of the optical receiver 11 and the optical receiver 13 are respectively branched into two, and one of them is input to the signal detection circuits 51 and 52. Further, each detection signal from the signal detection circuits 51 and 52 is input to the channel switching circuit 53. The channel switching circuit 53 includes the optical receivers 11 and 13
The other one of the two output signals of is input as the main signal. Channel switching circuit 53
Responds to each detection signal of the signal detection circuits 51 and 52, selects a channel in a predetermined priority order, and connects the reception signal of the selected one channel to the electric input / output interface 7. ing.

Although various detection operations can be considered for the signal detection circuits 51 and 52, in the present embodiment, signal detection is performed using the mono-multi vibrators 511 and 521. In the signal detection circuits 51 and 52, the time constant of the mono-multivibrator 511 is previously set to the resistor 512 so that the output time of the high (“H”) level detection signal becomes equal to the maximum packet length in the transmission signal and the reception signal. , 513 and capacitor 514,
The time constants of the mono-multi vibrator 521 are set by the resistors 522, 523 and the capacitor 524, respectively.

The channel switching circuit 53 is an OR circuit 531.
And a inverting circuit 532, and an inverting circuit 53.
3, two AND circuits 534, 535 and OR circuit 5
And a circuit composed of 36. In this channel switching circuit 53, the output of the OR circuit 531 is fixed to "H" or "L" in response to the detection signals from the signal detection circuits 51 and 52. In this embodiment, the signal detection circuits 51 and 52 are logically configured such that the optical receiver 11 is prioritized when the optical receiver 11 and the optical receiver 13 simultaneously receive.

Next, the signal detecting operation of the signal detecting circuits 51 and 52 and the selecting operation of the channel switching circuit 53 will be described in detail.

Optical signals transmitted through an optical fiber (not shown) are received by the optical receivers 11 and 13, and are converted into electric signals by the optical receivers 11 and 13, respectively. The electric signals from the optical receivers 11 and 13 are supplied to the selection circuit 5
Signal detection circuits 51 and 52 and a channel switching circuit 53.

<When both the optical receivers 11 and 13 detect a signal>

First, while the signals are being output from both the optical receivers 11 and 13, the signal detecting circuits 51 and 52 are
The output signal (detection signal) is fixed at "H" level.
Therefore, the channel switching circuit 53 gives priority to the optical receiver 11 and gives the output signal of the optical receiver 11 to the electrical input / output interface 7. This is because it operates as follows.

That is, when "H" is output from the optical receiver 11 and the optical receiver 13 at the same time, "H" is input to each input terminal of the OR circuit 531 and "L" is output from the inverting circuit 532, respectively. Although it is input, "H" is output from the OR circuit 531. Thereby, the AND circuit 535
"H" is input to one of the input terminals of the AND circuit 5
The “L” is input from the inverting circuit 533 to one input terminal of 34. Therefore, the AND circuit 535
Passes the output signal from the optical receiver 11, and the AND circuit 53
Since 4 does not pass the output signal from the optical receiver 13, the output signal of the optical receiver 11 is output from the OR circuit 536. As a result, the output signal from the OR circuit 536 is input to the electric input / output interface 7.
In this case, the optical receiver 11 has priority.

<When the optical receiver 11 detects a signal and the optical receiver 13 does not detect a signal>

In this case, the optical receiver 11 outputs "H" and the optical receiver 13 outputs "L". Therefore, "H" is applied to each input terminal of the OR circuit 531 and the inverting circuit 532.
To “H” are input respectively. As a result, "H" is output from the OR circuit 531. As a result, “H” is input to one input terminal of the AND circuit 535, and “L” is input to the one input terminal of the AND circuit 534 from the inverting circuit 533. Therefore, since the AND circuit 535 passes the output signal from the optical receiver 11 and the AND circuit 534 does not pass the output signal from the optical receiver 13, the OR circuit 536 outputs the optical receiver 1 to the optical receiver 1.
The output signal of 1 is output. As a result, the OR circuit 53
The output signal from 6 is input to the electric input / output interface 7. As described above, also in this case, the optical receiver 11 is prioritized.

<When the optical receiver 11 does not detect a signal and the optical receiver 13 detects a signal>

In this case, the optical receiver 11 outputs "L" and the optical receiver 13 outputs "H". Therefore, "L" is applied to each input terminal of the OR circuit 531 and the inverting circuit 532.
To "L" are input respectively. This causes the OR circuit 531 to output "L". As a result, "L" is input to one input terminal of the AND circuit 535, and "H" is input to the one input terminal of the AND circuit 534 from the inverting circuit 533. Therefore, since the AND circuit 535 does not pass the output signal from the optical receiver 11 and the AND circuit 534 passes the output signal from the optical receiver 13, the OR circuit 536 outputs the optical receiver 13 to the optical receiver 13.
The output signal of is output. As a result, the OR circuit 536
The output signal from is input to the electrical input / output interface 7. As described above, in this case, the optical receiver 13 has priority.

<When neither of the optical receivers 11 and 13 detects a signal>

In this case, the optical receiver 11 outputs "L" and the optical receiver 13 also outputs "L". Therefore, "L" is applied to each input terminal of the OR circuit 531 and the inverting circuit 532.
To “H” are input respectively. As a result, "H" is output from the OR circuit 531. As a result, "H" is input to one input terminal of the AND circuit 535, and "L" is input to the one input terminal of the AND circuit 534 from the inverting circuit 533. Therefore, since the AND circuit 535 passes the output signal from the optical receiver 11 and the AND circuit 534 does not pass the output signal from the optical receiver 13, the OR circuit 536 outputs the optical receiver 1 to the optical receiver 1.
The output signal of 1 is output. As a result, the OR circuit 53
The output signal from 6 is input to the electric input / output interface 7. Thus, in this last case, the optical receiver 11 will be prioritized.

As described above, in this embodiment, when the optical signals are simultaneously received by both the optical receiver 11 and the optical receiver 13, the prioritized optical receiver (in this embodiment, the optical receiver is used). 11) will be normally connected to the electrical input / output interface 7.

As described above, in this embodiment, the selection circuit 5 including the signal detection circuits 51 and 52 and the channel switching circuit 53 is provided, and even when a plurality of optical receivers 11 and 13 simultaneously receive optical signals. , The reception signal of the prioritized optical receiver (optical receiver 11 in this embodiment) can be normally taken out, and also regarding the duplication of the network, a plurality of optical receivers 11 and 13 are simultaneously received and one system is used. Even if there is a failure in the system, it will automatically switch to reception on another system,
Duplication becomes possible.

In the embodiment, the priority optical receiver is the optical receiver 11, but it is not limited to this.

[0033]

As described above, according to the present invention, a selection circuit having a signal detection circuit and a channel switching circuit is provided, and even when optical signals are simultaneously received by a plurality of optical receivers, priority optical signals are received. The reception signal of the receiver can be taken out normally.

Further, according to the present invention, when a plurality of optical receivers are simultaneously receiving optical signals, even if a failure occurs in one system, the selection circuit described above automatically switches the reception to another system. Therefore, the network can be duplicated.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an optical transceiver of the present invention.

FIG. 2 is a block diagram showing a conventional optical transceiver.

[Explanation of symbols]

 1, 3 Optical transmitter 5 Selection circuit 7 Electric input / output interface 11, 13 Optical receiver 51, 52 Signal detection circuit 53 Channel switching circuit

Claims (2)

[Claims] 1. An optical transceiver comprising a plurality of optical transmitters for simultaneously transmitting one type of signal by a plurality of optical transmitters and a plurality of optical receivers for respectively receiving a plurality of optical signals, wherein a plurality of optical transceivers are provided. Each output signal from the receiver is taken in, the presence or absence of each output signal is detected, and one of the output signals can be selected according to a predetermined channel priority order based on the detection signal corresponding to the duration of the received signal. An optical transceiver comprising a selection circuit. 2. A plurality of signal detection circuits for outputting a detection signal corresponding to the duration of the reception signal when the selection circuit detects the presence or absence of each reception signal from each optical receiver; 2. The optical transceiver according to claim 1, further comprising: a channel switching circuit that selects a priority channel of a reception signal from each optical receiver according to each detection signal based on the channel priority order.