JPS6238632A - Optical fiber communication method - Google Patents

Abstract

PURPOSE:To attain optical fiber communication by one kind of optical transmitter/receiver independently of master/slave equipments by changing over the mode into the reception mode so as to allow the system to be in standby with the data reception from an opposite equipment after the data is sent with the transmission mode. CONSTITUTION:An optical transmitter/receiver 1 consists of an optical transmitter/receiver 2 executing transmission/reception of a data to an optical fiber and a controller 3 composing of a CPU controlling the transmission/ reception of the optical transmitter/receiver 2. When a power at the station A is applied at a point of time tA, after an optical transmitter/receiver of a station A sends a data (a) with the transmission mode at first and is in standby with the data reception from an opposite station B while the mode is switched to the reception mode. The optical transmitter/receiver of the station A receives a data (b), is brought into the transmission mode and sends next a data C, is switched to the reception mode to be in standby with the data reception from the opposite station B. Thus, one kind of the optical transmitter/receiver is to be manufactured, the mass-production cost is made cheaper and the handling and management are facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an optical fiber communication method for performing bidirectional communication using a single optical fiber.

<Summary of the Invention> When an optical transmitting/receiving device is powered on, it first transmits data in a transmitting mode, then switches to a receiving mode and waits to receive data from the other party's device. When data is received, it switches to transmit mode and sends the data, and after transmission is completed, it switches to receive mode and waits to receive data from the other device. Optical fiber communication is possible with one type of optical transmitter/receiver.

<Background of the Invention> The applicant of the present invention recently proposed an optical transmitter/receiver device configured to perform bidirectional communication using a single optical fiber (Utility Application No. 198063/1983).

This type of device requires switching between transmission and reception, but in this case, if the local station and the other station switch between transmission and reception at the same timing, no communication will be possible. In order to avoid such a situation, a method was proposed in which one optical transmitter/receiver is a base unit and the other optical transmitter/receiver is a slave unit, and the transmission and reception of the base unit and slave unit are switched based on instructions from the base unit (“ Electronic Science J May 1980 issue, No. 55
~pages 59). However, in order to implement this method, it is necessary to manufacture two types of optical transmitter/receiver devices: a base unit and a slave unit, which not only increases mass production costs but also makes handling and management complicated, especially during installation. However, there were problems such as the need to be careful about the combination of the parent device and the slave device.

<Object of the invention> This invention is intended to solve the above problems,
It is an object of the present invention to provide a novel optical fiber communication method that allows bidirectional communication to be performed using one type of optical transmitting/receiving device without making a distinction between a parent device and a slave device.

<Configuration and Effects of the Invention> In order to achieve the above object, the present invention provides a communication system that performs bidirectional communication between optical transmitting and receiving devices connected by a single optical fiber, in which the optical transmitting and receiving device is powered on or When resetting, the device first transmits data in transmit mode, then switches to receive mode and waits to receive data from the other device.If data is received during receive mode, it switches to transmit mode and transmits data, After the transmission is complete, the device switches to receive mode and waits to receive data from the other device.

According to this invention, two-way communication can be performed using one type of optical transmitter/receiver without making a distinction between a master unit and a slave unit, so it is only necessary to manufacture one type of optical transmitter/receiver, and the mass production cost is low. Not only does it become easier to handle and manage, it also eliminates the need to pay attention to the combination of the parent unit and slave unit during installation, achieving the remarkable effects of achieving the purpose of the invention.

<Description of Embodiments> Fig. 1 is a diagram for explaining the principle of the optical fiber communication method of the present invention, and the figure shows transmission and reception operations at each station A and B connected by one optical fiber. are shown in relation to each other.

In FIG. 1, when the power of station A is turned on at time tAO, the optical transmitter/receiver of station A first transmits data a in transmission mode, then switches to reception mode and
Wait to receive data from. At this point, station B side is
The power has not been turned on yet, so the data a sent earlier is invalid.

Next, when the power of station B is turned on at time t, the optical transmitter/receiver of station B first transmits data b in transmission mode.
After that, it switches to reception mode and the other station A
Wait to receive data from. This data b is received by the optical transmitter/receiver of the A station since the A station is in standby in reception mode. After receiving the data, the optical transmitter/receiver of station A switches to transmission mode and then transmits data C.
After that, it switches to reception mode and the other station B
Wait to receive data from.

The next data d is also transmitted from station B in the same order and received at station A. As a result, the optical transmitter/receiver at station B switches to receive mode and receives the data from station A. Wait for reception.

FIG. 2 shows an example of the configuration of an optical transmitter/receiver 1 used to implement the optical fiber communication method of the present invention.

The illustrated device 1 includes an optical transceiver 2 that transmits and receives data to and from an optical fiber, and a CPU (Central Pro) that controls the transmission and reception operations of the optical transceiver 2.
A control device 3 consisting of a cessing unit (
(hereinafter simply referred to as rcPUJ).

The optical transceiver 2 has an OUT terminal for sending received data to the CPU 3, an IN terminal for taking in transmitted data from the CPU 3, and a T/R for setting the transmitting/receiving mode.
This T/R terminal has a level “
When it is set to "Lo-", the transmission mode is set, and when it is set to "old gh", it is set to the reception mode.

The CPU 3 includes an arithmetic operation unit 4 (hereinafter simply rALUJ).
, first to third input/output capacitors) 5, 6.7 each having an 8-bit configuration, and a communication controller 8, and these components are connected by a bus 9. In the illustrated example, among the input/output boats, the first port 5 is used for input, the second port 6 is used for output, and the third port 7 is used for input.
The eighth bit is used for controlling the T/R terminal.

The communication controller 8 has a control register 10 (
IBUFII converts the serial data received by the optical transceiver 2 into parallel The 0BUF 12 converts the parallel data taken in from the bus 9 into serial data and sends it to the optical transceiver 2.

The 5CONIO has three types of flags for communication control,
That is, a reception enable flag (hereinafter referred to as "rREN flag"), a reception completion flag (hereinafter referred to as "rRI flag"), and a transmission completion flag (hereinafter referred to as rTITI flag) are sent. When the REN flag is "0", reception is prohibited, and when it is set to "1", reception is enabled. Furthermore, the R1 flag is set to "1" when reception is completed, and the TI flag is set to "1" when transmission is completed, and these flags are cleared by the program shown in Figure 3. (See steps 3 and 10 in Figure 3).

FIG. 3 shows the flow of transmission/reception control operations in the CPU 3.

Assuming that the power of the optical transmitter/receiver 2 is turned on or reset at the current start, the respective flags of the 5 CONIO are as follows: the REN flag is "0", the R■ flag is "1", and the TI flag is "0". Initialized. Next, in step 1 (indicated by rsTIJ in the figure), "00'" (H in the figure means hexadecimal) is written in the third boat 7 in hexadecimal notation. The 8th bit becomes “Low” level, and the optical transmitter/receiver 1
is in transmit mode.

In the next step 2, transmission data is read from the first port 5 and written to 0BUF12.

In the next step 3, after clearing the RI flag of 5CONIO to "0", 0BUF12 is set to parallel
The serially converted data is output to the optical transceiver 2 and transmitted to the other party. Once this transmission is complete, the TI
The flag becomes "1" and the determination in step 4 becomes YES, and in the next step 5 "80" is written in hexadecimal notation to the third boat 7. As a result, the third boat 7
The 8th beat reaches the level of "Old gh", and the optical transmitting/receiving device 2 enters the receiving mode.Then, in the following step 6, the REN flag of 5CONIO is set to "1",
The device 1 is set to a receivable state and remains in a standby state until data reception from the partner station is completed. In this case, if the power of the partner station is off, the optical transmitter/receiver 2 remains in the reception mode and stands by to receive data.

In this way, data is received from the partner station, and when the reception is completed, rRT=1? in step 7? ” is judged as “
YES”, and in the next step 8, IBUF
The received data written in II is serial-parallel converted and then sent to second port 6 via bus 9.

Next, in step 79, the REN flag of 5CONIO is cleared to "0" and reception is prohibited, and in the next step 10, the TI flag of 5CONIO is cleared to O' in preparation for the next data transmission. and return to step 1.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the principle of the optical fiber communication method of the present invention, FIG. 2 is a diagram showing an example of the configuration of an optical transmitter/receiver used in implementing the invention, and FIG. 3 is a diagram for explaining the transmitter/receiver of the optical transmitter/receiver. It is a flow chart showing control operation. 1... Optical transceiver device 2... Optical transceiver 3.
...CPU

Claims (1)

[Claims] In a communication system that performs bidirectional communication between optical transmitting and receiving devices connected by a single optical fiber, the optical transmitting and receiving device includes:
When the power is turned on or reset, data is first transmitted in transmit mode, then switched to receive mode to wait for data reception from the other device. An optical fiber communication method characterized by transmitting data, and after completion of transmission, switching to a receiving mode and waiting for data reception from a partner device.