JP2002335213A - Optical communication transceiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical communication transceiver, which can realize a tone function without remarkably altering an existing device. SOLUTION: The transceiver 2 has a modulation circuit 7 for modulating a bias operating signal in a data signal transmitted from a host device 1 and is provided with a signal generating part 3 for generating an optical output signal for operating the output of an optical laser diode 4 on the basis of a modulation circuit operating signal transmitted from the modulation circuit 7 and an operation switching part 8 for switching and controlling an ordinary operating mode for continuously operating the output of the optical laser diode 4 on the basis of the modulation circuit operating signal transmitted from the modulation circuit 7, a tone operating mode for detecting the term of the modulation circuit operating signal transmitted from the modulation circuit 7 in a tone signal generating term T and operating the output of the optical laser diode 4 in the tone signal generating term T and a stop mode for stopping the modulation circuit operating signal and the bias operating signal and stopping the output operation of the optical laser diode 4 while sharing the same signal line 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical communication transceiver provided with a transceiver for converting an optical pulse signal transmitted between a host device and another device through an optical fiber cable into an electric pulse signal for transmission and reception.

[0002]

2. Description of the Related Art In recent years, when a host device such as an OA device such as a personal computer or an AV (Audio Visual) device such as a digital video camera is provided with various communication functions to perform data communication, data is transmitted in real time such as voice and moving images. The need to do it is growing. That is, IEEE 1394
Isochronous transmission is performed in which a data frame is transmitted to a receiving side while maintaining a timing transmitted by a transmitting side using a high-speed interface such as the above. In order to transmit and receive data to and from another communication device in this manner, the host device is provided with a transceiver as an access device having both a transmitter (transmission function) and a receiver (reception function). In particular, in order to transmit and receive data with a large amount of information such as voice and moving images at high speed, optical communication has been used favorably.
OF (Plastic / Optical / Fiber)
In many cases, data communication is performed using an optical fiber cable.

An example of an optical communication transceiver provided in the host device will be described with reference to FIG. Data is transmitted and received between the host device 51 such as a personal computer and a digital video camera and another device using an optical fiber (for example, POF) cable. The data signal transmitted from the host device 51 via the bus line 52 is transmitted to the transceiver 53.

The transceiver 53 includes a signal generator 54 such as a serial interface (not shown), an encoder, an optical transmitter, an optical receiver, and a decoder. Modulation circuit (external circuit) provided on bus line 52
To 55, a modulation control signal is transmitted from the host device 51 through a control line 56 to perform modulation, generate a modulated data signal, and transmit the modulated data signal to the signal generation unit 54. Signal generator 54
The modulated data signal (electric pulse signal) transmitted to the optical transmitter (not shown) is converted into an optical pulse signal (LD light output signal) obtained by modulating a bias signal by an optical transmitter (not shown), and the optical laser diode 57 is operated to output. I have. Further, when the LDDisable signal is transmitted from the LDDisable terminal of the host device 51 to the signal generation unit 54 via the signal line 58, the bias signal and the modulation signal are stopped. In addition, transceiver 53
The optical pulse received by the optical receiver is converted into an electric pulse signal by an optical receiver, and the decoder decodes the electric pulse signal for a serial interface. The transceiver 53 shown in FIG. 3 is provided with five transmission terminals and five reception terminals.

In order to support the plug-and-play function of the host device 51, a tone function may be added to confirm whether or not an optical fiber cable is connected to another device. In this tone function, when the host device 51 transmits a tone signal at a predetermined cycle through the optical transceiver 53 and a transceiver provided in another device receives the tone signal, the tone signal is sent back to confirm the connection. I have. If the host device 51 cannot confirm the tone signal for a predetermined time, it is determined that the connection of the optical fiber cable to another device is insufficient, and the host device 51 continues to output the tone signal.

[0006]

In this case, in order to add a tone function to the existing transceiver 53, the modulation circuit 55 provided outside the transceiver 53 is modified or a signal line for generating a tone signal is added. Accordingly, it is necessary to increase the number of terminals for transmitting and receiving tone signals to and from the host device 51 and the signal generation unit 54 of the transceiver 53, respectively, and it is necessary to significantly modify the existing device. In particular, if the number of devices that perform data communication with the host device 51 via the optical fiber cable increases, it is expected that the need to easily add a tone function to the existing transceiver 53 will increase.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide an optical communication transceiver capable of realizing a tone function without largely changing an existing device configuration.

[0008]

To solve the above-mentioned problems, the present invention has the following arrangement. That is, a transceiver that performs transmission and reception by converting an optical pulse signal transmitted through an optical fiber cable between a host device and another device into an electrical pulse signal, and converting the electrical pulse signal into an optical pulse signal and transmitting the signal is transmitted. In the optical communication transceiver provided, the transceiver has a modulation circuit for modulating a bias operation signal in a data signal transmitted from a host device, and an optical semiconductor device based on the modulation circuit operation signal transmitted from the modulation circuit. A signal generating unit for generating an optical output signal for operating the output circuit, a normal operation mode for continuously operating the optical semiconductor device based on the modulation circuit operation signal transmitted from the modulation circuit, and a tone signal from the modulation circuit to the signal generation unit. The period of the modulation circuit operation signal transmitted at the generation cycle is detected, and the optical semiconductor element is output at the tone signal generation cycle. An operation switching unit for switching and controlling the tone operation mode to be operated and the stop mode to stop the output operation of the optical semiconductor device by stopping the modulation circuit operation signal and the bias operation signal by sharing the same signal line; It is characterized by.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In this embodiment, a host device and another device are connected to a POF (Plastic / Optical).
al. Fiber) cable, IEEE
An optical communication transceiver that performs communication using a serial interface bus of the 1394 specification will be described. FIG.
FIG. 2 is a block diagram showing a configuration of an optical communication transceiver, and FIG. 2 is a timing chart showing a relationship between a data signal transmitted from a host device and an operation mode of the transceiver.

First, a schematic configuration of the optical communication transceiver will be described with reference to FIG. 1 is a host device,
An apparatus capable of performing data communication processing such as a personal computer or a digital video camera is assumed. The host device 1 exchanges POF (plastic / optical) with another device (not shown).
al. Fiber) cable for data communication. Reference numeral 2 denotes a transceiver, and the host device 1
It has both a transmitter (transmitting function) and a receiver (receiving function). That is, the transceiver 2
An optical pulse signal to be transmitted to another device is generated from an electric pulse signal transmitted from the host device 1, and an electric pulse signal to be transmitted to the host device 1 is generated from an optical pulse signal transmitted from another device through a POF cable. The signal generator 3 is provided.

The signal generation unit 3 includes a serial interface conforming to the IEEE 1394 specification capable of transmitting audio and video in real time, an encoder for encoding a clock signal transmitted at a predetermined baud rate into an electric pulse signal, and an electric pulse signal as an optical pulse signal. It includes a transmitter for conversion, an optical receiver for receiving an optical pulse signal, a decoder for converting the optical pulse signal to an electric pulse signal for a serial interface, and the like. In addition, the signal generation unit 3 is provided with an optical laser diode (LD) 4 as an optical semiconductor element for transmitting an optical pulse signal. The encoder and the decoder may be provided as individual circuits, or may be provided on an IC chip such as an ASIC together with the serial interface.

The host device 1 and the transceiver 2 are connected through a bus line 5 and a signal line 6. The transceiver 2 is provided with a transmitting terminal to which the bus line 5 and the signal line 6 are connected and a receiving terminal for receiving an optical pulse signal from another device. The bus line 5 includes a modulation circuit 7 that modulates a bias signal among data signals transmitted from the host device 1. The output operation of the optical laser diode (LD) 4 is performed based on the LD light output signal generated through the modulation circuit 7.

Reference numeral 8 denotes an operation switching unit, which operates in a normal operation mode in which the optical laser diode (LD) 4 performs a continuous output operation based on a modulation circuit operation signal transmitted from the modulation circuit 7;
The period of the modulation circuit operation signal transmitted at the tone signal generation period from the modulation circuit 7 is detected, and the optical laser diode (L
D) The same signal line 6 for a tone operation mode in which the output operation of the optical laser diode (LD) 4 is stopped by stopping the output operation of the optical laser diode (LD) 4 by turning off the modulation circuit operation signal and the bias operation signal. For switching control.

The tone operation mode is a function added to the IEEE 1394 specification for confirming the connection of a POF cable with another device in accordance with the plug and play of the host device 1. Specifically, a modulation control signal transmitted from the host device 1 to the modulation circuit 7 through the control line 9 transmits a modulation circuit operation signal to the signal generation unit 3 in a tone signal generation cycle, and based on the modulation circuit operation signal. The light laser diode (LD) 4 is used for tone output operation. The other device that receives the tone signal sends the tone signal back to the host device 1 so that the POF cable connection is confirmed.

In the stop mode, the LD of the host device 1
The output operation of the optical laser diode (LD) 4 is stopped (the bias operation signal and the modulation circuit operation signal are turned off) based on a stop signal transmitted from the Disable terminal through the signal line 6.

The operation switching section 8 controls switching from the tone operation mode to the normal operation mode or the stop mode by sharing the same signal line 6. That is, the operation switching unit 8 detects the tone signal generation period T of the modulation circuit operation signal transmitted from the modulation circuit 7 to the signal generation unit 3 in the tone operation mode. If the tone signal is not received for a longer time T ′, the POF cable is determined to have a poor connection, and the switching control is performed so as to shift to the stop mode.

Referring to the timing charts shown in FIGS. 2A to 2E, the relationship between the data signal transmitted from the host device 1 and the operation mode of the transceiver 2 will be specifically described. First, when data communication such as voice or moving image is performed from the host device 1 to another device, the data communication is started from the tone operation mode, and the connection of the POF cable to the other device is confirmed. At this time, from the host device 1, FIG.
The continuous signal of “1” “0” shown in (e) is transmitted to the transceiver 2 through the bus line 5. The host device 1
A modulation control signal is transmitted from the LDDisable terminal to the modulation circuit 7 through the signal line 6. This modulation circuit 7
In FIG. 2, a modulation circuit operation signal obtained by modulating the bias operation signal shown in FIG.
2 (b)) is transmitted to the signal generator 3, and the optical transmitter generates an LD light output signal (signal detect signal) shown in FIG. 2 (d). This LD light output signal (signal detect signal) outputs a continuous signal of “1” and “0” at a predetermined cycle.

The operation switching section 8 connected to the signal line 6 detects the tone signal generation period T of the modulation circuit operation signal (see FIG. 2 (a) LDDisable terminal input signal). This cycle detection is performed by, for example, a timer circuit or a counter provided in the operation switching unit 8. In this embodiment, the pulse width of the LD light output signal (signal detect signal) is 666 μs, and the pulse interval of the tone signal is set to IEEE.
It is set to 42.67 ms, which is the 1394 standard.

In the tone operation mode, a received signal corresponding to an LD light output signal (signal detect signal) is output from another device by a tone signal generation period T (for example, 42.62 m).
s + 666 μs) (T <t <T
In '), it is determined that the tone operation is good (that is, the connection of the POF cable is good), and the mode can be shifted to the normal operation mode. In the normal operation mode, the bias operation signal and the modulation circuit operation signal are continuously output, and the transmission data (electric pulse signal) such as voice and image from the host device 1 is converted into the optical pulse signal by the transceiver 2 and transmitted through the POF cable. To the device. According to the IEEE 1394 standard, communication can be performed at a data communication speed of about 100 Mbps to 400 Mbps. When the transmission of the transmission data from the host device 1 is completed, the modulation circuit operation signal is stopped as shown in FIG. 2C, but the bias operation signal in the signal generator 3 is kept ON.

The timing of transition from the tone operation mode to the stop mode may be a case where the period is longer than the tone signal generation period T (for example, t = 50 ms). It is preferable to set the time T ′ to have a margin longer than the signal generation period T.

According to the above configuration, the transceiver 2 incorporates the modulation circuit 7 that modulates the bias operation signal among the data signals transmitted from the host device 1.
The tone function can be realized without any modification such as modification of a modulation circuit or addition of a signal line. Particularly, when the switching operation is controlled by sharing the same signal line 6 between the tone operation mode in which the modulation circuit operation signal is transmitted to the modulation circuit 7 in the tone signal generation cycle and the stop mode in which the output operation of the optical laser diode 4 is stopped. Does not need to add new terminals to the host device 1 and the transceiver 2, and can easily realize a tone function using existing transmission / reception terminals.

Although the preferred embodiments of the present invention have been described in various forms, the present invention is not limited to the above-described embodiments. For example, the host device is not limited to a digital video camera, but may be a personal computer or various other devices. A communication device such as a personal digital assistant (PDA) may be used.
Of course, many modifications can be made without departing from the spirit of the invention, such as not only OF but also glass.

[0023]

The optical communication transceiver according to the present invention has a built-in modulation circuit for modulating the bias operation signal among the data signals transmitted from the host device, so that the optical fiber cable can be used for the existing host device. When performing communication, the tone function can be realized without modification such as modification of a modulation circuit or addition of a signal line. In particular, a tone operation mode for transmitting a modulation circuit operation signal to the modulation circuit,
In the case where the operation switching unit controls switching between the stop mode for stopping the output operation of the optical laser diode and the same signal line by using the same signal line, it is not necessary to add new terminals to the host device and the transceiver, and the existing transmission / reception is not required. The tone function can be easily realized using the terminal.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an optical communication transceiver.

FIG. 2 is a timing chart showing a relationship between a data signal transmitted from a host device and an operation mode of a transceiver.

FIG. 3 is a block diagram illustrating a configuration of a conventional optical communication transceiver.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Host apparatus 2 Transceiver 3 Signal generation part 4 Optical laser diode 5 Bus line 6 Signal line 7 Modulation circuit 8 Operation switching part 9 Control line

Claims (1)

[Claims] An optical pulse signal transmitted between a host device and another device through an optical fiber cable is converted into an electric pulse signal, and the electric pulse signal is converted into an optical pulse signal and transmitted, thereby transmitting and receiving. An optical communication transceiver comprising a transceiver that performs a modulation circuit that modulates a bias operation signal in a data signal transmitted from the host device, and modulates a modulation circuit operation signal transmitted from the modulation circuit. A signal generation unit that generates an optical output signal that causes the optical semiconductor device to perform an output operation based on the normal operation mode that continuously outputs the optical semiconductor device based on a modulation circuit operation signal transmitted from the modulation circuit; A circuit detects a cycle of a modulation circuit operation signal transmitted at a tone signal generation cycle to the signal generator, and The same signal line is shared between a tone operation mode in which a semiconductor element is output in a tone signal generation cycle and a stop mode in which the modulation circuit operation signal and the bias operation signal are stopped to stop the output operation of the optical semiconductor element. An optical communication transceiver, comprising: an operation switching unit for performing switching control.