JPH0323024B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a method of controlling communication between devices disposed in a distributed manner.

Conventional configuration and its problems In order to centrally control multiple devices or monitor the current status of devices, each device is connected through an electrical transmission channel and transmits control signals to each other. Various suitable transmission control methods have been reported.
One example is a method in which a commercial 100V electric light line is used as a transmission communication path to control electrical appliances in a general household. This superimposes a communication signal voltage of a sufficiently higher frequency on top of the 50Hz or 60Hz alternating current voltage of the electric light line to communicate between each device, and since special wiring for control is not required, it is easy to install. It has the advantage of requiring little effort and cost. Here, the equipment refers to the electrical appliance to be controlled, the sensor function that detects whether the electrical appliance is energized (hereinafter referred to as ON state) or de-energized (hereinafter referred to as OFF state), and the electrical appliance that controls ON/OFF of the appliance. A control module that has a control function to transmit and receive control signals to and from other devices and a communication function to send and receive control signals to and from other devices. In addition, as a control device, there is a communication function that sends and receives control signals to and from each device, a control signal generation function that generates ON/OFF control signals that are transmitted to each device, and a control signal generation function that generates ON/OFF control signals to be transmitted to each device.
There is a control terminal that has a monitor display function that displays the status.

The transmission control method using the electric light line will be explained in detail below with reference to the drawings.

FIG. 1 is a block diagram of a conventional transmission control method using electric light lines. 1 is a commercial 100V light line,
It is something that can be found in ordinary households. The devices 2, 3, and 4 are each a combination of electric devices 5, 6, and 7 and control modules 8, 9, and 10, and are connected to the electric light line 1, respectively. As mentioned above, the control modules 8, 9, and 10 have sensor, control, and communication functions, and detect and control the ON/OFF status of the electric appliances 5, 6, and 7 combined with themselves, and also control the electric lights. Communicate with other devices using line 1 as a transmission communication path. The control terminal 11 is a type of equipment, is connected to the electric light line 1, and is used for communication and communication as described above.
Has control signal generation and monitoring functions. Further, each device 2 to 4, 11 has an individual index number to distinguish it from other devices. The index number is a number set in advance for each device, and the index number storage means 12, 1
3, 14, and 15. Now, equipment 2, 3,
It is assumed that the index numbers of 4 are set to 1, 2, and 3 in order, and the index number of the control terminal 11 is set to 0. A control signal sent from one device must indicate which device is to be controlled, and must also request a reply if necessary. Therefore, the control signal is composed of a local station index number indicating the device to which the control signal was transmitted, a partner station index number indicating the device to be controlled, and a command indicating the content of the control. For example, the electrical appliance 5 that is in the OFF state is activated by a control signal from the control terminal 11.
Suppose you want to change it to ON state. Control terminal 11
When a control request occurs, it transmits a control signal on the light line 1 consisting of the local station index number 0, the partner station index number 1, and an ON command. The control signal transmitted on the electric light line 1 is received by any of the devices 2, 3, and 4. When each device receives a control signal, it first compares the other station's index number with its own index number, and if they are different, it ignores this control signal, and if they match, it sends a control signal. Executes control according to instructions. i.e. equipment 2
only follows the command and the appliance 5 is changed to the ON state by the control function of the control module 8. When the control module 8 confirms that the electric appliance 5 has turned on, it then issues a control signal to the control terminal 11 containing a command to notify that the electric appliance 5 has turned on. Control terminal 11
When receiving this control signal, the appliance 5 of device 2
displays on the monitor that it is in the ON state. The above is a series of transmission control processes. In this transmission control method using index numbers, mutual control of a large number of devices can be performed using a single transmission communication path, since the own station and the other station can be identified by index numbers, making installation easy. It has the advantage of being possible.

In the conventional transmission control method described above, control requests may be made simultaneously from a plurality of devices in some cases, and control signals may collide on the transmission communication path. This occurs when there are multiple control terminals on the transmission channel. When control signals collide, data generally collapses, making necessary control impossible and subsequent communication disrupted. There are two possible ways to avoid this. The first method is to immediately stop transmitting control signals and simultaneously cancel the control request when the device detects a collision. Although this method does not cause any confusion in communication thereafter, it has the disadvantage that necessary commands do not reach the other device, resulting in malfunctions for the user, such as non-execution of control or incorrect display on the monitor. The second method is to stop transmission in the same way as the previous method, and then each device calculates a random number, waits for a waiting time corresponding to the random number, and then retransmits the control signal. Although this method can also eliminate communication confusion, it has the disadvantage that the smaller the number of digits in the random number, and the greater the number of devices on the transmission communication path, the higher the possibility of re-collision or repeated collision. If the number of digits is increased, the waiting time becomes longer and the communication speed becomes slower.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a transmission control method that solves the above-mentioned conventional problems and returns to a normal communication state in a short time when a collision of control signals occurs.

Structure of the Invention In order to solve the above conventional problems, the present invention provides a plurality of devices capable of communicating with each other and each having an index number storage means, a clock generation means, an arithmetic means, and a communication means, and a transmission communication path connecting them. When a control signal collides on the transmission channel, the device immediately stops transmitting the control signal, and then, if necessary, resumes transmitting the control signal after a period of the last waiting clock common to the index number. In addition, since the minimum waiting clock period is an integral multiple of the half-cycle period of the electric light line power source, stable collision avoidance processing can be performed without any error in the latest waiting clock period.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. Second
The figure is a configuration diagram of a transmission control method showing an embodiment of the present invention. Electric light line 16 has equipment 17, 18, 19
and a control terminal 20 are connected. The devices 17, 18, 19 are electrical appliances 21, 2, respectively.
2, 23 and control modules 24, 25, 26 are combined. Control module 2
4, 25, and 26 have control, sensor, and communication functions, and the control terminal 20 has communication, control signal generation, and
It has a monitor display function, and each has one electric light line.
They can communicate with each other using 6 as a transmission communication path.
Each device also has a different index number to distinguish it from other devices. The index number is a number set in advance for each device, and the index number storage means 27,
28, 29, and 30. The index number storage means 27, 28, 29, and 30 consist of a combination of a plurality of changeover switches.

FIG. 3 shows the inside of the device 17 as a representative among the devices 17 to 20. The electric light line 16 has a communication means 31
, a control means 32 and a sensor means 33 are connected to each other, and these are also connected to an arithmetic control means 34 . Also connected to the calculation control means 34 are an index number storage means 27 and a clock generation means 35. The clock generating means 35 calculates and controls the period for transmitting the minimum unit of the signals used for communication.
It generates a voltage with regular cycles to notify the power supply voltage.In communication using the electric light line 16 in synchronization with the commercial power supply voltage, the period of one clock is regarded as a half cycle of the power supply voltage (10 moliseconds at 50Hz). There is. With this configuration, when a control command reaches the device 17 from the control terminal 20, the arithmetic control means 34
When the control command is received via the control command and it is confirmed that the index number therein is equal to that of the index number storage means 27, the control means 32 is caused to carry out the necessary control. Further, the calculation control means 34 is connected to the sensor means 33.
Once information on the change in the ON/OFF state is obtained, a notification command to that effect is transmitted to the control terminal 20 via the communication means 31 and the electric light line 16. Here, control modules 24, 25, 26 and control terminal 20
always monitors the transmission signal on the electric light line 16, and when a transmission signal other than that transmitted by itself is present on the electric light line 16, transmission of the transmission signal is prohibited.

FIG. 4 represents the transmitted signal on the light line 16.

Waveform A is a signal voltage superimposed on a power supply voltage, and waveform B is a signal voltage component. The signal voltage of clock C is in the first half of the half cycle of the power supply waveform, and this is set to logic 0. Clock D
The signal voltage is in the second half of the half cycle of the power supply waveform, and this is set to logic 1. In this way, communication can be performed using the clock cycle T as half the cycle of the power supply waveform.
Now, when signals collide, signal voltages are generated in both the first half and the second half of the clock period T, as shown by clock E. At this time, if the device 17 monitors the electric light line 16, the fact of a collision can be easily detected, so the arithmetic control means 34 immediately stops the transmission. Clock E shows no signal.

FIG. 5 shows the transmitted signals before and after the collision. Assume that the control signals transmitted by the device 17 and the control terminal 20 collide at clock _T1 . In this case, the index number storage means 27 of the device 17 is set to number 1,
The index number storage means 30 of the control terminal 20 is 0.
is set to number. Also, each device 17, 18, 1
9 and control terminal 20 are commonly programmed to inhibit transmission for at least three clocks after a collision is detected. These three clocks are called the minimum waiting clocks. Now, after the collision, the calculation control means 34 in each device
First, add the three minimum waiting clocks and the value in its own index number storage means 30, and set this value as its own waiting clock period. That is, in the device 17 this becomes 4 clocks, and in the control terminal 20 this becomes 3 clocks. After the collision occurs, transmission is prohibited during this waiting clock period. That is, the control terminal 20 is prohibited from transmitting during the three clock periods of clock _T2 , and starts transmitting control signals from clock _T3 . Clock T ₃ and clock T ₄ are control signals for a series of control terminals 20 . Now, in one device 17, the waiting clock period is 4 due to the collision of clock _T1 , and transmission is prohibited during the 4 clock period between clock _T2 and clock _T3 . Therefore, device 17 receives the clock immediately after the end of clock _T3 .
Although it is possible to transmit from the beginning of clock T ₄ , the signal from control terminal 20 already exists at clock T ₃ immediately before that, and the transmission signal path is blocked, so the signal sent from the control terminal (clock T ₃ Wait for the completion of +T ₄ ). After confirming that the transmission signal path is not used for four clocks (the waiting clock period of the device 17) indicated by clock _T5 , control signal transmission is started from clock _T6 . If this operation process is applied to all devices not involved in the collision, the wait clock periods of each device will all be different, and no collision will occur again.

Furthermore, if the index number of the control terminal 20, which is the device that performs control, is set to a smaller value than the index numbers of the devices 17, 18, and 19 that are controlled, as in this embodiment, retransmission is possible in the event of a collision. has the highest priority on the control terminal 20. In this way, control commands from the control terminal 20 that need to be given a relatively high priority can be transmitted continuously, and conversely, control commands from the control terminal 20 that need to be given a relatively high priority can be transmitted from the devices 17, 18, and 19 that need to be given a relatively low priority.
The notification command to 0 is postponed, resulting in smooth communication control.

Here, the common lowest waiting clock is set to 3, but the gist of the present invention does not change even if this is an integer of 1 or more. Furthermore, although the waiting clock period is the sum of the lowest waiting clock and the index number, it may be an integral multiple of the minimum waiting clock period or a fixed value may be added to the sum without changing the gist of the present invention.

In addition, here, the transmission communication channel is an electric light line, and the waiting clock period is a half cycle period of the electric light line power supply, or an integral multiple thereof, but it is not necessary to use a clock synchronized with the cycle of the electric light line power supply. The gist of the present invention does not change regardless of whether coaxial lines, parallel lines, optical cables, etc. are used.

As described above, in the present invention, when a signal collision occurs, the waiting clock period corresponding to the sum of the predetermined minimum waiting clock and the index number that takes a unique value for each device is set as the period during which transmission of control signals of each device is prohibited. The waiting clock period is set to a different value for all devices, so that the communication transmission path can be quickly returned to a normal state without causing another collision.

Effects of the Invention The present invention provides different wait clock periods for all devices when a signal collides on a transmission channel, thereby eliminating the re-collision or repeated collision that occurred in the past, and quickly clearing the communication channel. It has the effect of returning to normal state. In addition, by determining the priority of retransmission after a collision using the index number setting method, it is possible to give top priority to the signals of control equipment that require high priority, and also to enable continuous control, making the use of transmission communication channels more efficient. It's also effective.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a conventional transmission control method, Fig. 2 is a block diagram of a transmission control method showing an embodiment of the present invention, Fig. 3 is a block diagram of the equipment configuration in Fig. 2, and Fig. 4 is a block diagram of a transmission control method showing an embodiment of the present invention. Transmission signal diagram on electric light line, No. 5
The figure shows transmission signal diagrams before and after the collision. 16...Light line, 17,18,19...Equipment,
20... Control terminal, 24, 25, 26...
Control module, 27, 28, 29, 30... index number storage means, 31... communication means, 34... arithmetic control means, 35... clock generation means.

Claims (1)

[Claims] 1 Consists of a plurality of devices that can communicate with each other, a control terminal that controls these devices, and an electric light line that serves as a transmission communication path connecting them, and the devices and control terminals are synchronized with the index number storage means and the power supply voltage of the electric light line, respectively. It has a clock generation means that generates a clock, an arithmetic control means, and a communication means, and when control signals collide on the transmission communication path, all devices and control terminals immediately stop transmitting the control signals, and then the index number A transmission control method in which the control signal is transmitted after a waiting clock period corresponding to the sum of the common minimum waiting clock and the minimum waiting clock period, and the minimum waiting clock period is an integral multiple of the half-cycle period of the electric light line power source. .