JP2003058284A - Ring shape optical communication system provided with wakeup function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ring shape optical communication system provided with a wakeup function capable of preventing the damage of a communication IC generated at the time of waking up a node in a sleep mode. SOLUTION: The node 2 connected to the optical communication system 1 constituted in a ring shape is provided with a reception FOT 4 converting optical signals to electric signals when the optical signals are inputted through an optical transmission line 3, a communication IC 6 receiving the electric signals outputted from the reception FOT 4 and a power source circuit 8 supplying driving power to the communication IC 6. Also, at the time of the sleep mode, the driving power to be outputted from the power source circuit 8 to the communication IC 6 is turned off. Then, when the optical signals are supplied to the reception FOT 4 at the time of the sleep mode, control is performed so as to supply the driving voltage outputted from the power source circuit 8 to the communication IC 6 before supplying the electric signals obtained by converting the optical signals to the communication IC 6. Thus, the damage of the communication IC 6 is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ring type optical communication system in which an optical transmission line is formed in a ring shape and data is transmitted between nodes (communication stations), and more particularly, it is set in a sleep state. Technology for waking up existing nodes.

[0002]

2. Description of the Related Art In recent years, vehicles such as passenger cars and one-box cars are equipped with audio equipment, navigation systems, etc.
A wide variety of devices are often installed. For example, as audio equipment, a CD player, M
A D player, a DVD player, etc. may be mounted, and a plurality of amplifiers, speakers, monitors, etc. may be mounted.

As described above, when a large number of devices are mounted in a vehicle, it is necessary to electrically connect the devices to each other, and such a connection becomes extremely complicated. Therefore, in recent years, It has been proposed to construct a network system in a vehicle and connect various devices to the network system to simplify the connection of various devices.

By using such a network system, for example, navigation image data obtained by the navigation system can be transmitted to a monitor via a signal transmission path and displayed on the screen of the monitor.

FIG. 5 is an explanatory view showing a configuration of a conventional example of a ring type optical communication system used in a network system. As shown in FIG. 5, the ring type optical communication system 101 has a plurality of nodes ( Each node 102 is connected in a ring shape via an optical transmission path 103 formed of an optical fiber. And
Data is transmitted between the nodes 102 by optical signals.

FIG. 6 is a block diagram showing a detailed structure of the node 102. As shown in FIG.
Is a reception FOT 104 that receives an optical signal distributed via the optical transmission path 103 and converts the optical signal into an electric signal, a communication IC 105 that receives the electric signal output from the reception FOT 104, and a drive to this communication IC 105. Receiving a power supply circuit 107 that outputs power for use and a status signal that is output when an optical signal is applied to the reception FOT 104,
The power supply circuit 107 is provided with a CPU 106 that performs control to output a power output request signal.

If the optical signal is not supplied to the receiving FOT 104 for a predetermined time or longer, the status signal from the receiving FOT 104 is turned off, and the CPU 106 puts the communication IC 105 into the sleep state through the power supply circuit 107. That is, by cutting off the power output from the power supply circuit 107, the mode is switched to the mode for reducing the power consumption.

Thereafter, when an optical signal is supplied to the reception FOT 104, the optical signal is received and the sleep state is switched to the wakeup state. Hereinafter, this operation will be described with reference to the flowchart shown in FIG.

First, when an optical signal is input through the optical transmission line 103 (step ST101), this optical signal is converted into an electric signal by the reception FOT 104, and a status signal is output to the CPU 106 (step). ST
102).

Then, the CPU 106 detects the status signal and outputs a drive power output request signal to the power supply circuit 107 (step ST103). Upon receiving this request signal, the power supply circuit 107 outputs driving power to the communication IC 105 (step ST104). This allows communication I
C105 is set in the wakeup state, and reception FOT10
It is possible to receive the electric signal output from the No. 4.

[0011]

However, in such a conventional ring type optical communication system 101, when the communication IC 105 is waked up, the communication IC 1
Before the driving power is supplied to 05, or at the same time as the driving power is supplied, the electric signal from the reception FOT 104 is
It may be supplied to the communication IC 105. In this case, since the communication IC 105 is not in a stable state,
When an electric signal is applied in such a state, an element (semiconductor element or the like) forming the communication IC 105 may be damaged or cause a malfunction.

Further, even if the driving power is supplied to the communication IC 105 earlier than the electric signal, if the communication IC 105 is not in a stable state, the same problem as described above occurs. To do.

The present invention has been made in order to solve such a conventional problem, and an object thereof is to make the communication IC when the communication IC is waked up.
An object of the present invention is to provide a ring type optical communication system equipped with a wake-up function capable of preventing damage to the device and occurrence of malfunction.

[0014]

In order to achieve the above object, the invention according to claim 1 of the present application has a plurality of communication stations, and each communication station is connected in a ring shape using an optical transmission line. In a ring type optical communication system for performing data transmission between the communication stations, at least one communication station among the communication stations outputs an optical signal when the optical signal is input through an optical transmission line. Photoelectric conversion means for converting into an electric signal, and a communication IC for receiving the electric signal output from the photoelectric conversion means
And a power supply circuit for supplying drive power to the communication IC, and in the sleep mode, the drive power output from the power supply circuit to the communication IC is turned off, and in the sleep mode, the photoelectric conversion means. When an optical signal is supplied to the communication IC, it is controlled to supply the drive voltage output from the power supply circuit to the communication IC before supplying the electric signal obtained by converting the optical signal to the communication IC. The feature is to do.

According to a second aspect of the present invention, there is provided a ring type optical fiber having a plurality of communication stations, which is connected in a ring shape using an optical transmission line to perform data transmission between the respective communication stations. In the communication system, at least one of the communication stations, when an optical signal is input via an optical transmission line,
A photoelectric conversion unit that converts this optical signal into an electric signal and a communication I that receives the electric signal output from the photoelectric conversion unit
C and a power supply circuit for supplying drive power to the communication IC, and in the sleep mode, the drive power output from the power supply circuit to the communication IC is turned off.
A logic circuit which is interposed between the photoelectric conversion means and the communication IC, sets an output timing of an electric signal output from the photoelectric conversion means, and outputs the electric signal to the communication IC; When the photoelectric conversion means receives the optical detection notification signal output when the photoelectric conversion means receives the optical signal, the drive request signal is output to the power supply circuit and the output timing of the drive request signal is lower than the output timing of the drive request signal. A control means for outputting an output request signal of an electric signal to the logic circuit at a late timing.

According to a third aspect of the present invention, the control means causes the communication IC to output to the communication IC before the output request signal of an electric signal is output to the logic circuit when the light detection notification signal is given. It is characterized by outputting a reset signal.

According to a fourth aspect of the present invention, the ring type optical communication system is mounted in a vehicle.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a ring type optical communication system according to an embodiment of the present invention. As shown in FIG. 1, the ring type optical communication system 1 includes a plurality of (four in the figure) nodes (communication). Station) 2 and each node 2 is connected by an optical transmission line 3 in a ring shape.

FIG. 2 is a block diagram showing a detailed configuration of the node 2. As shown in the figure, the node 2 includes a reception FOT (photoelectric conversion means) 4 for converting an optical signal distributed via the optical transmission line 3 into an electric signal, a logic circuit 5,
Communication IC 6, CPU (control means) 7, and power supply circuit 8
It is equipped with.

The logic circuit 5 receives the electric signal Rx1 output from the reception FOT 4 and outputs the electric signal Rx2 when the logic circuit ON signal (electrical signal output request signal) output from the CPU 7 is supplied. Output to the communication IC 6.

The CPU 7 outputs a status signal (light detection notification signal) output when the reception FOT 4 receives the light signal.
Is input, a power-on request signal is output to the power supply circuit 8, then a reset signal is output to the communication IC 6, and after a predetermined time has elapsed, a logic circuit on-signal is output to the logic circuit 5.

The power supply circuit 8 is a communication IC during normal operation.
6, and other components (reception FOT 4, logic circuit 5, CPU 7) are supplied with driving power, and in the sleep mode, power supply to the communication IC 6 is stopped to reduce power consumption. In the sleep mode, power is supplied to the reception FOT 4, the logic circuit 5, and the CPU 7.

FIG. 3 is a flow chart showing the operation of the node 2 in the sleep mode, and FIG. 4 is a timing chart showing the change of each signal in the node 2. Below, with reference to these figures, the present embodiment will be described. The operation will be described.

As described above, when the node 2 is in the sleep mode, the power supply from the power supply circuit 8 to the communication IC 6 is stopped, and the communication IC 6 is in the stopped state. In this state, when an optical signal of an empty frame (a signal in which no data is written in the frame) via the optical transmission line 3 shown in FIG. 1 is input to the reception FOT 4 (FIG.
Step ST1; time t1 in FIG. 4), this optical signal is
The reception FOT 4 converts the electric signal Rx1 into the electric signal Rx1, and the electric signal Rx1 is supplied to the logic circuit 5. Further, a status signal (light detection notification signal) is output to the CPU 7 (step ST2; time t2). When the CPU 7 detects the input of the status signal,
A power-on request signal is output from the CPU 7 to the power supply circuit 8 (step ST3; time t3). Upon receiving the power-on request signal, the power supply circuit 8 starts supplying power to the communication IC 6 (step ST4; time t4).

After a certain time has passed (step S
T5), the CPU 7 outputs a reset signal for initializing the communication IC 6 (step ST6; time t5).
As a result, the communication IC 6 is supplied with drive power from the power supply circuit 8 and is in a reset state.

Then, when a certain period of time has elapsed (step ST7), the CPU 7 outputs a logic circuit ON signal to the logic circuit 5 (step ST8; time t).
6). When the input of this logic circuit ON signal is detected, the logic circuit 5 outputs the signal (empty frame) Rx1 given from the reception FOT 4 as Rx2 (step ST9; time t7).

As a result, the communication IC 6 has the reception FOT 3
Electrical signal Rx2 output from the logic circuit 5
Since the communication IC 6 has already been supplied with driving power and initialized at this time,
It does not impose a heavy burden on the various circuit elements that compose 6. Then, the wakeup of the communication IC 6 is completed (step ST10).

In this way, in the ring type optical communication system 1 according to the present embodiment, when the optical signal is input to the reception FOT 4 when the communication IC 6 is in the sleep mode, The electric signal Rx1 thus obtained is once input to the logic circuit 5, and thereafter, when the logic circuit ON signal is given to the logic circuit 5, the electric signal Rx1 is inputted.
x2 is output to the communication IC 6. At this time, the communication IC 6 has already been supplied with driving power and initialized, so that it does not place a heavy burden on various elements forming the communication IC. Therefore, it is possible to prevent damage to the element and occurrence of malfunction.

The ring type optical communication system 1 according to this embodiment is extremely useful when used as a network system mounted on a vehicle. That is, in the network system installed in the vehicle, it is desired to keep battery voltage consumption as low as possible, and the communication IC 6 is often set to the sleep mode. By using
Trouble at wake-up can be effectively prevented.

[0030]

As described above, in the ring type optical communication system having the wakeup function according to the present invention, when the communication station (node) is in the sleep mode, the optical signal is transmitted to the communication station. When input, the electric power output from the photoelectric conversion means is supplied to the communication IC after the driving power output from the power supply circuit is first supplied to the communication IC.
Since it is supplied to the communication IC, it is possible to prevent an electric signal from being given before the communication IC reaches a stable state, and avoid occurrence of troubles such as damage to elements constituting the communication IC. be able to.

If a reset signal is output to the communication IC before the electric signal output from the photoelectric conversion means is supplied to the communication IC, the communication IC can be initialized. The influence on the circuit can be further reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a ring type optical communication system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a node connected to a ring type optical communication system.

FIG. 3 is a flowchart showing an operation when waking up a node in a sleep mode.

FIG. 4 is a timing chart showing changes in respective signals when waking up a node in a sleep mode.

FIG. 5 is a configuration diagram showing a conventional ring type optical communication system.

FIG. 6 is a block diagram showing a configuration of a node connected to a conventional ring type optical communication system.

7 is a flowchart showing an operation when an optical signal is input to the node shown in FIG.

[Explanation of symbols]

1 Ring type optical communication system 2 nodes (communication station) 3 Optical transmission line 4 Reception FOT (photoelectric conversion means) 5 logic circuits 6 Communication IC 7 CPU (control means) 8 power supply circuit

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5B011 DA01 DC07 EA09 FF04 LL11                 5K002 DA05 DA09 DA11 EA03 EA04                       FA01 GA07                 5K031 AA07 DA19 DB06 DB12 EC01

Claims (4)

[Claims] 1. A ring type optical communication system having a plurality of communication stations, wherein each communication station is connected in a ring shape using an optical transmission line to perform data transmission between the communication stations, At least one communication station among the stations, when the optical signal is input through the optical transmission line, photoelectric conversion means for converting the optical signal into an electric signal, and an electric signal output from the photoelectric conversion means. Communication IC to be received and the communication IC
And a power supply circuit for supplying drive power to the photoelectric conversion means in the sleep mode, turning off the drive power output from the power supply circuit to the communication IC in the sleep mode, and supplying an optical signal to the photoelectric conversion means in the sleep mode. In this case, before the electric signal obtained by converting the optical signal is supplied to the communication IC, the drive power output from the power supply circuit is controlled to be supplied to the communication IC. A ring type optical communication system having a wake-up function. 2. A ring type optical communication system having a plurality of communication stations, wherein each communication station is connected in a ring shape using an optical transmission line to perform data transmission between the communication stations, At least one communication station among the stations, when the optical signal is input through the optical transmission line, photoelectric conversion means for converting the optical signal into an electric signal, and an electric signal output from the photoelectric conversion means. Communication IC to be received and the communication IC
A power supply circuit for supplying drive power to the communication IC, and in the sleep mode, the drive power output from the power supply circuit to the communication IC is turned off. A logic circuit for setting an output timing of an electric signal output from the photoelectric conversion means and outputting the electric signal to the communication IC; and when the sleep mode is set, the photoelectric conversion means outputs an optical signal. In response to the light detection notification signal output when the signal is received, the drive request signal is output to the power supply circuit, and the electric signal is output to the logic circuit at a timing later than the output timing of the drive request signal. A ring type optical communication system having a wake-up function, comprising: a control unit that outputs a request signal. 3. The control means outputs a reset signal to the communication IC before outputting an output request signal of an electric signal to the logic circuit when the light detection notification signal is given. A ring type optical communication system having the wake-up function according to claim 2. 4. The ring type optical communication system having the wake-up function according to claim 1, wherein the ring type optical communication system is mounted in a vehicle.