JPH09298513A - Optical communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a communication means not requiring a new optical transmission line by using a communication execution request signal in a slave station so as to minimize the number of times of use of optical communication as required. SOLUTION: A loop transmission channel is formed by the central processing unit 1 decided to be a start point and electric board units 2-5 having an equipment in itself whose start sequence are decided in advance, the optical communication equipment of the central processing unit 1 is used for a master station and the optical communication equipment of the electric board units 2-5 is used for a slave station and optical communication is executed among the master station and the slave stations. Communication data and a synchronization clock sent from the master station are received by the slave station, where they are converted into electric signals. The electric signals are sent in the loop transmission line in the order of the master station, the slave station 1, the slave station 2, the slave station 3, the slave station 4, and the master station 1. Then the content of the communication data are all replaced with input data from each slave station finally and the resulting data are received by the CPU of the master station.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical communication device for exchanging information between a plurality of electric base units.

[0002]

2. Description of the Related Art Conventionally, an optical communication apparatus for exchanging information between a plurality of electrical base units positions a CPU of a central processing unit for controlling the operation of the entire apparatus as a main station for optical communication, and a plurality of other units. The electric board unit is positioned as a slave station for optical communication to exchange information in the device.

This optical communication transmission line configuration includes a case where a master station and a plurality of slave stations are connected in a one-to-one manner, and a loop type transmission and communication means in which a master station and a plurality of slave stations are connected in a loop. . The loop transmission communication means receives data transmitted from the master station by one slave station and transmits the succeeded data to the slave station located next. Then, the slave station sequentially receives and transmits the data that the slave station has inherited. At the end, the data taken over from the slave station to the master station returns.

Further, in the data which has been exchanged for information exchange, each slave station takes in an information portion secured at a predetermined position or identifier as output data from the master station, and inputs generated at that slave station at the same position of the data. By adding data, the input data of each slave station is finally taken in by the master station.

As described above, in the loop type transmission communication means, a transmission line for optical communication can be constructed if there is only one set of light receiving element or light emitting element possessed by each station for one type of signal, so that, for example, a master station and a plurality of slave stations are provided. Compared to a transmission line such as one-to-one connection, it can be realized with a simple structure and at a relatively low cost.

On the other hand, the transmission signal form can be roughly classified into a synchronous type and an asynchronous type, but in the case of the asynchronous type, a clock generator and a synchronization circuit etc. are required for each station, so that the clock is costly. In many cases, a synchronous method is used in which data and data are paired and transferred via two transmission lines.

[0007]

However, in the above-mentioned conventional loop type transmission communication means, in order to detect a change in the input information of a plurality of slave stations with time, the optical communication of a certain short cycle is performed. The execution must be repeated. This means that the optical communication must be continuously executed regardless of whether or not there is a change in the state of the output information from the CPU, which is the master station, and whether or not there is a change in the input information of the electrical base unit, which is the slave station. Therefore, there is a fear that the life of the infrared LED, which is a light emitting element, may be shortened. In other words, as long as the device is powered on, the master station must always collect input / output information in order to always grasp the input information at the slave station. As a result, the loop-type transmission communication means has the following drawbacks.

(1) Since the infrared LED having a longer life has to be used, the cost is increased.

(2) In the case of using a general infrared LED, when the input information in the slave station changes, a request to execute communication is issued to the master station. Therefore, when the master station changes the output information for the slave station,
Alternatively, the optical communication is executed only when the communication execution request signals from the plurality of slave stations are received, so that the optical communication can be executed a minimum number of times. Therefore, although it is possible to cope without extending the life of the infrared LED, the addition of the communication execution request signal requires a pair of light emitting element and light receiving element to be newly provided in the main station, which increases the cost. Occurs.

(3) Since the light emitting element is an infrared LED, when an abnormality occurs in the device such as the light emitting element or the light receiving element of any station, it takes a lot of time to find and replace the faulty station. Will be required. In other words, it is difficult to identify an abnormal station because the loop-shaped configuration replaces a station that does not respond in one-to-one communication.

An object of the present invention is to solve the above-mentioned problems,
Using the communication execution request signal in the slave station, it realizes a communication means that suppresses the number of times of optical communication use to the necessary minimum and does not add a new optical transmission line, and detects an abnormality in the loop transmission line of optical communication. An object of the present invention is to provide an optical communication device capable of indicating an abnormal point.

[0012]

An optical communication apparatus according to the present invention for achieving the above object is an optical communication means for exchanging information between a plurality of electrical base units, and is a master station and a plurality of slave stations. In an optical communication device having a loop-type transmission communication means connected in a loop, the receiving device included in the plurality of slave stations has a light receiving element that receives an optical signal emitted from a higher station, and the light emitted from the higher station. In addition to the signal, the light receiving element has a second light emitting element provided at a position capable of irradiating an optical signal, and the second light emitting element is controlled to blink by the slave station itself which receives the optical signal emitted from the upper station. It is characterized by having a self-luminous instruction control means.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the illustrated embodiment. FIG. 1 is a block circuit configuration diagram showing a loop-shaped transmission line of the present optical communication. In FIG. 1, a plurality of electric board units 2 to 5 are provided for a central processing unit 1 that controls the operation of the entire apparatus. In the optical communication of the present embodiment, the electrical processing base units 2 to 5 arranged in the apparatus from the central processing unit 1 are preliminarily determined in order in accordance with the convenience of the closed loop optical path to form a loop transmission path. There is. Then, the optical communication device included in the central processing unit 1 is used as a master station, and the optical communication devices included in the electrical base units 2 to 5 are used as slave stations to perform optical communication. The optical communication mode using the loop-shaped transmission line described in this embodiment is for explaining the present invention, and is not particularly limited.

FIG. 2 is a circuit configuration diagram of the slave station, and 11 is a power-on reset circuit, which is a time constant circuit composed of a resistor and a capacitor. Reference numeral 12 is a light receiving unit having a light receiving element for receiving an optical signal emitted from a higher station and a photoelectric conversion circuit, 13 is a receiving unit for receiving a synchronizing clock, and 14 is L
It is a light emitting unit having an ED drive circuit and an LED, and belongs to the light receiving unit 13. Reference numeral 15 is a light emitting portion including an LED for emitting a synchronization clock to the next slave station and an LED driving circuit, and 16 is a similar light emitting portion for emitting an optical signal.

Reference numeral 17 is a shift register for shifting and latching the photoelectrically converted data length, and 18 is a shift register controlling timing adjusting circuit for controlling the shift register 17, which is mainly composed of a counter circuit. 19
22 is an output unit consisting of a motor and a solenoid,
The output data from the main station, which is output from the shift register 17, is held in the latch circuits 23 to 26, and each of the drive circuits 2
It is driven by 7 to 30. 31-3
Reference numeral 4 denotes an input unit composed of a photo interrupter and a tact switch, which is received by the receive circuits 35 to 38, held by the latch circuits 39 to 42, input to the shift register 17, and transmitted to the main station.

Reference numeral 43 is an exclusive OR circuit 44-4.
A multi-input OR circuit that receives the output of 7 as an input, 48 is an AND circuit that determines the presence or absence of output by the control signal from the shift register controlling timing circuit 18, and 49 is an OR circuit.

As for the master station, the CPU of the central processing unit 1 is connected to the latch circuits 23 to 26 and 39 to 42 connected to the parallel input / output terminals of the shift register 17 as compared with the slave station shown in FIG. The configuration is connected and basically the same as the configuration of the slave station, and therefore the illustration is omitted.

The synchronizing clock emitted from the master station is received as an optical signal by the receiving section 13 of the slave station located next and is converted into an electrical signal. Communication data is received by the light receiving unit 12,
It is converted into an electric signal and input to the shift-in terminal of the shift register 17. One of the synchronizing clocks is used as a shift clock of the shift register 17 and is input to the shift register controlling timing circuit 18 to execute communication data processing described later. The other side is converted into an optical signal again by the light emitting unit 15 and is optically transmitted to the next station.

FIG. 3 is a block diagram of the receiving section 13. A signal checking LED 52 and a light receiving element 53, which are the light emitting section 14, are provided on a board 51 which constitutes an electric board unit. It is arranged at a position where the emitted light is incident. The LED 52 and the light receiving element 53 are covered with a light shielding case 55 provided with a window 54, and the light receiving element 53 is capable of receiving an optical signal from a higher station through the window 54. The optical signal and the optical signal from the LED 52 are configured to be wired OR in an optical state.

As described above, since the LED 52 is arranged close to the light receiving element 53, the LED 52 for substrate check, which is the cheapest, can be used as a substitute, and the wired optical signal can be formed with a very simple and easy structure. OR can be realized.

Next, communication data processing of optical communication in this embodiment will be described with reference to the timing chart of FIG. In this timing chart, the data and clock transmitted from the master station are input, and in addition to the processing in the master station 1, the slave station 2, the slave station 3, and the slave station 4 are also illustrated.

The communication data and the synchronizing clock transmitted from the master station are received by the light receiving sections 12 and the receiving sections 13 of the slave stations and converted into electric signals. The synchronization clock is input to the shift register control timing acquisition circuit 18 and is mainly frequency-divided to generate a predetermined timing signal.
7 is controlled. The data length of one slave station in this embodiment is defined as 8 bits.

In the slave station, a latch signal is output when 8 bits are shifted into the shift register 17 from the beginning of the communication data, and the latch circuits 23 to 26 of the parallel output terminals are output.
It controls each output unit as output data from the main station. For convenience of description, the slave station located next to the master station is defined as the slave station 1, and the slave stations subsequent thereto are defined as the slave station 2, the slave station 3, and the slave station 4 in order. Therefore, in the loop transmission line, the master station, the slave station 1,
The slave station 2, the slave station 3, the slave station 4, and the master station are transmitted in this order.

The states of the latch signals from the input portions of the electric board units 2 to 5 are simultaneously held in the latch circuits 39 to 42, taken into the shift register 17, and sequentially shifted out. Therefore, in the slave station 1, the 8 bits at the beginning of the communication data are replaced with the output data from the slave station 1 to the input data from the slave station 1. Similarly, the slave station 2 shifts in the received communication data, and a latch signal is output every 24 bits from the beginning to replace the communication data. The slave stations 3 and 4 operate similarly except that the output timing of the latch signal is different. And
Finally, the contents of the communication data are all replaced with the input data from each slave station and taken into the CPU of the master station.

Before explaining the communication control operation in the master station, the communication request signal generated in the slave station will be described with reference to FIG. Each slave station is provided with exclusive OR circuits 44 to 47 for the input data to the master station one to one. These exclusive OR circuits 44 to 47 are connected from the receive circuits 35 to 38 to the latch circuits 39 to 42 and the parallel input terminals of the shift register 17, and the latch circuits 39 to 42.
The presence or absence of state change is detected by comparing the input state and the output state of.

That is, the latch circuit 3 that has been shifted out and held until the latch signal is output from the timing register circuit 18 for controlling the shift register during communication execution.
When the input state is changed and updated with respect to the outputs of 9 to 42, the exclusive OR circuits 44 to 47 react due to the different signal states. Of course, if there is no change in the input state, the exclusive OR circuits 44-4
7 does not react.

FIG. 5 shows a timing chart. Since these exclusive OR circuits 44 to 47 are configured for each input, if any one of the input states changes after the latest communication is executed, the OR circuit A communication request signal is generated at the output of 43. As described above, the communication request signal is generated for each slave station, and is cut off by the AND circuit 48 by the timing register circuit 18 for shift register control during communication execution. The method for determining whether communication is in progress is not particularly limited, but it may be determined that communication is in progress while the synchronization clock is being input, for example. Specifically, the frequency divider circuit is increased by one stage in the shift register control timing adjustment circuit 18, and the input of the AND circuit 48 is controlled by the 1/128 frequency division output.

Therefore, when a communication request signal is generated during non-communication, the LED of the light emitting section 14 provided in the receiving section 13
52 emits light, and the wired OR optical signal is superimposed on the transmission path used as the synchronization clock transmission path during communication.

As described above, while the optical communication of the loop-shaped transmission line starting from the master station is executed, each slave station detects the communication request signal when the communication is not executed, and the slave clock station uses the clock line for synchronization. An operation of transmitting a signal to the main station is performed using a certain transmission path. By this communication request signal, information exchange by optical communication is executed only when the signal state changes, so that information is transmitted with the minimum necessary number of times of communication. That is, when the central processing unit 1 which is the master station changes the output signals to the electric base units 2 to 5 which are slave stations,
By setting the communication to be executed only when the communication request signal from each slave station is received, the information transmission is executed with the minimum necessary number of times of communication. As a result, the life of the optical communication device can be extended.

Communication control in the main station will be described with reference to the flowchart of FIG. The circuit configuration of the master station has a communication device and a receiver similar to those of the slave station and is composed of a shift register. The CPU is connected to the parallel input / output terminals of the shift register and the control by the CPU is executed. . The bit length of the shift register in this case is 8
It has a 32-bit structure which is the number of slave stations of bit data. The circuit configuration of this main station is not shown because it does not participate in the present invention.

In FIG. 6, for ease of explanation,
Controls other than the optical communication control of the device are omitted.
The main program of the CPU controls each control of the device in a task form, and inputs each task at a predetermined cycle to execute parallel processing. The flow of the program shown in FIG. 6 is one of the tasks and controls the optical communication in this embodiment.

In FIG. 6, when an optical communication task is input from the main program, it starts at step 70,
In step 72, it is checked whether 5 seconds have passed since the power was turned on. This is to determine whether or not to execute a loop-shaped transmission line abnormality check described in the second and third embodiments described later. In this embodiment, the process proceeds from step 72 to step 73 without proceeding to step 71. In step 73, the presence or absence of communication in the CPU processing is checked by the output data update flag. This is a flag that is set when the instruction data is held in a predetermined memory when the output data to the electric board unit is updated in each control task. If any one of them is updated, it is set as an optical communication request.

If the output data is not updated, the reset state is entered, and therefore the process proceeds to step 74, and the synchronizing clock output terminal for optical communication is switched to the input mode. And
In step 75, the communication request signal from the slave station described above is checked. If it is determined that there is no communication request signal, switching is executed to return the synchronizing clock output terminal switched to the input mode in step 76 to the output mode again. Then, in step 77, this task is terminated and the input is waited for again.

On the other hand, if it is determined in step 73 that the output data has been updated, or if it is determined in step 75 that the communication request signal has been received, the process proceeds to step 78, and optical communication is executed. In step 78, the synchronization clock output switched to the input mode in step 74 is returned to the output mode, and the synchronization clock signal can be output. Then, in step 79, the output data for communication is transferred to the shift register, and in step 80, the clock count value for controlling the output number of the synchronization clock is reset.

At step 81, the shift operation of the output data set in the shift register is started by outputting the synchronizing clock. Then, the output synchronization clock count is checked in step 82, the clock count value is incremented in step 83, and the process returns to step 81. By repeating the steps 81 to 83, the synchronization clock count value reaches a predetermined value, and the process moves from step 82 to step 84. At step 84, the reply input data from each slave station is shifted in the shift register as shown in the timing chart of FIG. Therefore, in step 84, the data information is read from the shift register and stored in a predetermined memory. The data-in information is individually extracted by a control task other than this task, and the operation control of the entire apparatus is executed.

As described above, in the first embodiment, the main station is originally in the loop transmission line for executing the optical communication for transmitting the output data from the central processing unit 1 to each of the electric base units 2-5. When the optical communication starting from the starting point is executed, the master station is set to the starting point by blocking the communication request signal from the slave station with the gate circuit and executing the optical communication, while detecting the synchronization clock count. When it is determined that the optical communication is not being executed, the gate circuit is opened so that the communication request signal issued from the slave station can be transmitted to the master station.

The transmission line for transmitting the communication request signal is
A light-emitting element is built in the receiving part in the synchronization clock transmission line that transmits the received signal as it is and emits light. By controlling the blinking according to the communication request signal, wired OR at the optical signal level is performed and the light is transmitted to the main station. Transmission becomes possible. Further, the slave station can detect the presence / absence of a communication request from the slave station by detecting the synchronization clock transmission line when not performing optical communication.

Therefore, one loop-shaped transmission line for executing optical communication can be easily entered by the slave station itself in addition to the optical communication starting from the original master station without adding a new transmission line. In addition, a signal from a slave station, which means another predefined meaning, can be transmitted to the master station. As a result, optical communication can be executed only when data is updated at the master station or when a communication request is issued from a slave station due to data update without newly adding an optical transmission line, and information is transmitted at the minimum necessary number of times. Is carried out,
The cost increase of the optical communication device can be suppressed and the service life can be extended.

Next, the timing chart of FIG. 7 and FIG.
The second embodiment will be described with reference to the flowchart of FIG. In the second embodiment, as in the first embodiment, a second signal source having a new meaning is added to the original loop transmission line for optical communication to the synchronization clock signal reception transmission line. ing. However, this is not for minimizing the number of times of communication in the first embodiment, but for checking an abnormality such as disconnection of a loop transmission line of optical communication.

In FIG. 2, the light emitting portion 14 built in the receiving portion 13 for receiving the synchronizing clock signal is provided with an output signal from the power-on reset circuit 11 in addition to the communication request signal of the first embodiment. The flashing control of the light emitting unit 14 can be executed. Further, the optical communication in the second embodiment is set so that the communication operation is not executed for 5 seconds after the power is turned on, as shown in FIG. In other words, in the second embodiment, the state check of the looped transmission line is executed from the time when the power is turned on until the optical communication operation is executed.

Power-on reset circuit 1 of each slave station
1 is set so that the time of the power-on reset signal is different for each slave station. Although a specific circuit is not shown in the drawing, it is a reset circuit composed of a very general resistor and capacitor, and the constant of the time constant circuit is changed to correspond to it. FIG. 7 is a timing chart showing the reset time of each slave station. The reset time is set so that the reset time becomes longer from the closest slave station 4 to slave station 1 in sequence when the optical signal of the master station is received. ing. Further, as shown by the arrow, the main station detects the synchronizing clock line of the loop transmission line of optical communication at a preset timing.

The signal from the synchronization clock transmitted to the master station immediately after the power is turned on is transmitted by the wired OR of light from the slave stations 1 to 4. After that, the slave station 4 is turned off at a preset time, in the vicinity of 2.3 seconds in the case of this embodiment, and similarly at a preset time interval, in the case of this embodiment, at an interval of 0.5 seconds. Slave station 3, slave station 2, slave station 1
Is turned off. On the other hand, the master station can confirm that the loop transmission line from the slave station 4 is normal by checking the signal at the synchronization clock while the slave station 4 is on. Then, while the slave station 4 is off and the slave station 3 is on, it is possible to confirm that the loop transmission line from the slave station 3 is normal by checking the signal based on the synchronization clock. In this way, it becomes possible to check the slave station 2 and the slave station 2 for the looped transmission path.

If there is an abnormality in the transmission line of the slave station 2 as shown in FIG. 7, normal reception is possible until the looped transmission line to the slave station 3 is turned off, but the signal remains off in the slave station 2. As a result, the error of the slave station 2 can be detected. In addition, in the second embodiment, even if there are abnormalities in a plurality of loop-shaped transmission lines, only one failure point determination can be detected. That is,
Although the error of the slave station 2 can be detected, other slave stations are unknown. However, in the case of a loop-shaped transmission line, if even one transmission line is cut off, it will not be able to function, so it is necessary to avoid a failure by a serviceman call. Therefore,
It suffices if even one failure point is found, and then the error points of the loop transmission line are individually dealt with during repair. Note that a control example in which all of a plurality of abnormal points can be pointed out by one control will be described in the third embodiment.

Next, using the flow chart of FIG.
The control at the main station will be described. In FIG. 8, if it is within 5 seconds after the power is turned on, the process proceeds from step 72 to step 90 in FIG. 6, and it is determined in step 90 whether 2 seconds have elapsed since the power was turned on. 5 seconds in step 72,
Although the timer for counting 2 seconds in step 90 is not shown in the figure, a high-order timer that controls each task processing by an event timer that the CPU has is used. Since this event timer is not intended by the present invention, its explanation is omitted. 2 in step 90
If it is determined that the second has not elapsed, the process moves to step 91, and this communication task ends. On the other hand, when 2 seconds have passed, the routine proceeds to step 92, and the abnormality check program control of the loop-shaped transmission line as shown in FIG. 7 is started.

First, in step 92, the memory content called the slave counter is set to 4 in the sense of the slave station 4. Then, in step 93, the timer is set to 0.5 seconds, and in step 94, the time is up. When the time is up, the output terminal set by the clock count for synchronization is switched to the input signal mode in step 95, and the signal state of the input terminal is detected. This is judged as the reset pulse from one slave station explained in FIG. 7 as the signal source for the loop transmission line check. Since it is normally on, the routine proceeds to step 97, where it is checked with the slave counter whether or not it has been executed by the number of slave stations. If the number of slave stations has not been reached, step 98 decrements the slave counter.

Then, the process returns to step 93 and the same operation is repeated. As a result of decrementing the slave counter in step 98, the slave count is 1, that is, slave station 1
Is returned to step 93, it is determined in step 97 that the predetermined value has been reached, and in step 99, step 9 is executed first.
The input signal terminal switched to the input mode in 5 is returned to the output terminal set by the original synchronization clock. Then, the line check of the loop transmission line of the optical communication according to the present embodiment is completed, it is determined that there is no abnormality, and the subsequent optical communication is executed. On the other hand, if there is an abnormality in the optical transmission / reception of any of the slave stations, it is determined in step 196 that the signal is off, and the process proceeds to step 101.

In step 101, the slave count is stored in the memory in order to hold the slave count which has continued the counting operation, and the process proceeds to step 102. In step 102, a transmission line failure error process execution flag for instructing to execute a process for issuing a repair request by contacting as a serviceman call by another error processing task is set. The actual serviceman call and the display of the error content are executed by the processing according to the definition unique to the device, and are not particularly limited in the present invention, so the detailed invention will be omitted.

Then, step 102 to step 9
9. Moving to step 100, this optical communication task is ended. Further, in the case of this program, once it is judged as a serviceman error, the main program of the CPU ends each control of the apparatus and stops the operation of the apparatus, so that the parallel processing is not executed according to the input of each task at a predetermined cycle. Therefore, the optical communication is also interrupted and waits for processing.

By the control of the second embodiment described above, it is possible to easily check the abnormality of the loop-shaped transmission line without adding a new optical communication device. In other words, by checking the loop transmission line of optical communication without executing optical communication at a specific timing such as after preset power-on, and if there is an error, the error location is stored and retained in the memory. There is an effect that signals other than the above communication can be transmitted by one line.

Next, the timing chart of FIG. 9 and FIG.
The third embodiment will be described with reference to the flowchart of FIG. As in the first embodiment, the third embodiment adds a second signal source having a new meaning to the original loop transmission line for optical communication to the synchronization clock signal reception transmission line. are doing. However, this is not for minimizing the number of times of communication in the first embodiment, but for checking an abnormality such as disconnection of a loop transmission line of optical communication.

Further, in the third embodiment, as compared with the control example in which the second embodiment can detect and display only the line failure by one slave station for the check of the loop transmission line, the line failure is detected by a plurality of slave stations. An example of control that can be displayed will be described. Therefore, in order to facilitate the description, the description of the same parts as those described in the second embodiment will be omitted.

The major differences between the third embodiment and the second embodiment are the reset pulse signal form from each slave station and the processing control after error detection in the master station. Further, in the case of the second embodiment, there is a definition such as the order of being closer to the light receiving portion of the main station, whereas in the case of the third embodiment, there is no particular definition regarding the order.

In FIG. 2, the light emitting portion 14 built in the receiving portion 13 for receiving the synchronizing clock signal is not limited to the communication request signal of the first embodiment, but may be output by the power-on reset circuit 1. The blinking control of the light emitting unit 14 can be executed. The optical communication in the third embodiment is set so that the communication operation is not executed for 5 seconds after the power is turned on as in the second embodiment. That is, in the third embodiment, the state check of the loop-shaped transmission line is executed from the time when the power is turned on until the optical communication operation is executed.

The reset pulse signal form of each slave station is configured to maintain the stop for a preset time by a time constant circuit composed of a resistor and a capacitor immediately after the power is turned on. Further, when the stop time has passed, a reset signal common to each slave station is output. Although the specific circuit configuration is not shown in the figure, a reset circuit composed of a general resistor and a capacitor is connected in two stages in series, and by changing the constant of the time constant circuit configured in the preceding stage. , The phase of the pulse generated in each slave station can be changed.

FIG. 9 is a timing chart showing the reset time of each slave station, and the reset pulse is set to be transmitted to the master station at a different timing for each slave station. Further, the main station detects the synchronizing clock line of the loop transmission line of the optical communication at the preset timing as shown by the arrow. The signal with the synchronization clock transmitted to the master station immediately after the power is turned on is transmitted in order from the slave station 1 to the slave station 4.

In the case of the present embodiment, first, the slave station 1 is turned on in a preset time, in the case of this embodiment, the slave station 1 is turned on in about 2.0 seconds, and similarly, in the present embodiment, the preset time is set. In the case of, it turns off in about 0.3 seconds. The slave station 2 is turned on after a predetermined time from the turn-on timing of the slave station 1, about 0.25 seconds in the case of this embodiment, and is turned off at the same time as the slave station 1. Further, the slave stations 3 and 4 are similarly turned on and off so that the slave stations do not overlap.

On the other hand, the master station can determine whether or not the loop transmission line is normal by checking the signals from the slave stations with the synchronization clock at the timings when the signals from the slave stations do not overlap. If the transmission path is normal, then FIG.
The ON state is continuously detected as in the case of no error shown in. On the other hand, when the slave station 2 and the slave station 4 have an error, the OFF state exists in the ON state as illustrated.
Therefore, unlike the second embodiment, a plurality of transmission path abnormalities can be confirmed.

The third embodiment is largely different from the control of the second embodiment in that the transmission line check is ended when an error is detected, whereas in the third embodiment, an error occurs. Regardless of the presence or absence, the signal check from all slave stations is executed and all error points are stored.

In the flowchart of FIG. 10, the second
Similar to the embodiment of the above, the process proceeds from step 90 to step 96, the input signal of the synchronizing clock signal line is checked in step 96, and if it is in the on state, the process proceeds to step 97. On the other hand, if it is determined in step 96 that the input signal is in the off state, in step 110 the slave count which means the slave station number currently being checked is read and the corresponding bit of the slave station error memory corresponding thereto is set. As a result, the occurrence location of the error slave station is stored and retained.

Then, the process goes to step 97 again to check the next slave station. After checking the error status in the slave station, step 97 to step 11
Moving to 1, all bits of the slave error memory stored in step 110 are checked. If there is no bit set, it is determined that the optical communication loop transmission line is normal,
From step 99, the input signal is returned to the synchronization clock signal output mode again, and optical communication is executed after a predetermined time. On the contrary, if any bit of the slave error memory is set, the process proceeds to step 112, and the same transmission line failure error processing execution flag as in the second embodiment is set,
After step 99, the optical communication task ends. In this case, similar to the second embodiment, the subsequent optical communication is interrupted and the operation of the device is stopped.

On the other hand, unlike the second embodiment, the serviceman call can display all the abnormal slave stations, so that an electric base unit to be replaced can be prepared in advance, and further easier processing can be performed. become.

By the control of the third embodiment, it is possible to easily check the abnormality of the loop transmission line without adding a new optical communication device. In other words, at a specific timing such as after preset power-on, check the loop transmission line of optical communication without executing optical communication,
If there is an error, the error location is stored and held in the memory so that a signal other than the original communication can be transmitted through one line.

[0063]

As described above, according to the optical communication device of the present invention, the slave station is the second station in the receiving section of the slave station itself.
By controlling the flashing of the light emitting element by the self-emission instruction control means, a signal indicating another instruction can be transmitted to the main station through the loop-shaped transmission path. On the other hand, if the master station detects a change in the loop-shaped transmission line when the optical communication originating from the master station itself does not use the loop-shaped transmission line, the master station processes the signal as a signal indicating another instruction from the slave station. To run. As a result, one loop-shaped transmission line can transmit a signal having a plurality of meanings by one line under a predefined condition. Therefore, it is possible for the slave station to interrupt the optical communication loop transmission line from which the master station originates and transmit a signal with a different meaning to the master station at the discretion of the slave station. Optical communication control can be executed with the minimum required number of lines without adding.

Further, the master station receives the optical signal from each slave station at each timing in a predetermined sequence immediately after the power is turned on, for example, so that the loop-shaped transmission line can be checked for abnormality. Since it is also possible for the slave station having an abnormality to easily judge, the processing can be facilitated.

[Brief description of drawings]

FIG. 1 is a block circuit configuration diagram showing a loop transmission line of optical communication.

FIG. 2 is a circuit configuration diagram of a slave station.

FIG. 3 is a configuration diagram of a receiving unit.

FIG. 4 is a timing chart of optical communication control.

FIG. 5 is a timing chart of communication request signal control.

FIG. 6 is a flowchart of optical communication control.

FIG. 7 is a timing chart of the optical communication control of the second embodiment.

FIG. 8 is a flow chart of optical communication control according to the second embodiment.

FIG. 9 is a timing chart of the optical communication control of the third embodiment.

FIG. 10 is a flowchart of optical communication control according to the third embodiment.

[Explanation of symbols]

 1 Central Processing Unit 2-5 Electric Board Unit 11 Power-on Reset Circuit 12 Light Receiving Section 13 Receiving Section 14, 15, 16 Light Emitting Section 17 Shift Register 44-47 Exclusive OR Circuit

Claims (3)

[Claims] 1. An optical communication device for exchanging information between a plurality of electric infrastructure units, the optical communication device having a loop type transmission communication means connected in a loop by a master station and a plurality of slave stations, wherein: In the receiving device of the slave station, a light receiving element for receiving an optical signal emitted from the higher station is provided, and the light receiving element is provided at a position where the light signal can be emitted to the light receiving element separately from the optical signal emitted from the upper station. 2. The optical communication device according to claim 1, wherein the second light emitting element includes a self light emission instruction control unit that controls blinking by a slave station itself that receives an optical signal emitted from the upper station. 2. The self-emission instruction control means included in the slave station has non-communication detecting means for determining whether or not optical communication from the master station is being executed, and the non-communication detecting means forms a loop transmission line. When it is determined that the master station has not been used, the master station has a light emission control signal that causes the second light emitting element to blink with a self-signal content generated by the slave station, which is set in advance, and the master station is configured to transmit the second The optical communication device according to claim 1, further comprising slave station signal transmission determining means for determining whether or not an optical signal from the light emitting element is received. 3. The self-emission instruction control means included in the slave station has a light emission control means for turning on the second light-emitting element at a preset timing and for a predetermined time, and the master station is the plurality of slave stations. It has an optical detection judging means for detecting whether or not an optical signal from the second light emitting element which it has has been received at a preset timing, and the abnormality detection of the loop-shaped transmission line is carried out by the detection result of the optical detection judging means. Run
The optical communication device according to claim 1, further comprising a transmission line self-diagnosis means capable of displaying a warning of an abnormal point.