WO2014141675A1

WO2014141675A1 - Communication system, and communication terminal

Info

Publication number: WO2014141675A1
Application number: PCT/JP2014/001332
Authority: WO
Inventors: 一彦五所野尾; 冉李; 基弘大井; 享伊藤
Original assignee: パナソニック株式会社
Priority date: 2013-03-13
Filing date: 2014-03-10
Publication date: 2014-09-18
Also published as: JP6089274B2; TWI501573B; JP2014176049A; TW201442447A

Abstract

In the present invention, a transmission base unit (base unit) and a plurality of communication terminals (extension units) are connected to a communication line (first communication line), the transmission base unit supplying drive power to the plurality of communication terminals via the communication line. The plurality of communication terminals perform, in synchronism with each other, transmission processing using an electric current signal (first signal) in only a communication period, and perform a state transition accompanying a fluctuation in drive power exceeding a prescribed width in only a load fluctuation period separate from the communication period.

Description

Communication system and communication terminal

The present invention generally relates to a communication system and a communication terminal, and more particularly to a communication system including a parent device and a child device, and a communication terminal used therefor.

Conventionally, as shown in FIG. 18, a transmission parent device 101 constituting a parent device and a plurality of communication terminals 102 constituting a child device are connected to the same communication line L100 to communicate with the transmission parent device 101 and each communication. A communication system for performing communication with the terminal 102 is provided.

As this type of communication system, a transmission parent device 101 and a plurality of communication terminals 102 are connected by a two-wire communication line L101, and communication between the transmission parent device 101 and each communication terminal 102 is performed by a time division multiplex transmission method. A system that realizes the above is known. Such a communication system is described in Japanese Patent Application Publication No. 2012-49638, for example.

In this communication system, when data is transmitted from the transmission master 101 to each communication terminal 102, a voltage signal having a predetermined amplitude for transmitting data by pulse width modulation is used. Further, when data is transmitted from each communication terminal 102 to the transmission base unit 101, a current signal obtained by changing the magnitude of the current is used.

Furthermore, the communication terminal 102 rectifies the transmission signal supplied from the communication line L100 to generate drive power for the communication terminal 102.

In conventional communication systems, as a power supply method to the slave unit, a drive power source is generated by rectifying and stabilizing the transmission signal transmitted from the transmission master unit through the communication line (stabilized power supply). Method).

However, if a terminal with relatively large current consumption such as a monitor terminal having an LCD (Liquid Crystal Display) or an information device having a CPU (Central Processing Unit) operating at a high speed is used as a slave unit, a transmission error occurs. There was a risk of occurrence. Specifically, the fluctuation of the current flowing through the communication line L100 (load fluctuation) increases due to the transition of the operating state of the slave unit (for example, LCD backlight on / off, video processing CPU activation / sleep). In this case, the current signal may be distorted and a transmission error may occur.

Here, for slave units with relatively large current consumption, a configuration in which driving power is supplied via a dedicated power supply wiring may be considered, but a dedicated power supply wiring is installed separately from the communication line. It was necessary and it was disadvantageous in terms of workability.

The present invention has been made in view of the above reasons, and its purpose is to provide driving power from the master unit to the slave unit, and even if the slave unit communicates using a current signal, the workability is improved. An object of the present invention is to provide a communication system and a communication terminal that can suppress transmission errors without deteriorating.

In the communication system of the present invention, a master unit and a plurality of slave units are connected to a first communication line, the master unit supplies drive power to the plurality of slave units via the first communication line, Each of the plurality of slave units sends a first signal, which is a current signal, to the first communication line, and the plurality of slave units perform transmission processing using the first signal only during a communication period in synchronization with each other. The state transition with the fluctuation of the driving power exceeding a predetermined width is performed only during a load fluctuation period different from the communication period.

In the present invention, each of the plurality of slave units includes a communication unit that performs the transmission process in a range in which the fluctuation of the driving power does not exceed the predetermined width, and a functional unit that executes a predetermined operation using the driving power It is preferable that the state transition is performed when the operation state of the functional unit transitions from the first state to the second state.

In the present invention, the master unit sends a second signal to the first communication line, and the second signal is divided into a plurality of time zones including the communication period and the load fluctuation period. The plurality of slave units operate using the second signal as the driving power, respectively, and based on the received second signal, the communication period and the load fluctuation period are respectively It is preferable to set.

In the present invention, there are a plurality of load variation periods, and the plurality of slave units perform the state transition by executing a control sequence, and a time length of the control sequence is a time length of the load variation period. The control sequence is divided into a plurality of control sequences, and at least two of the plurality of sequences are executed in different load fluctuation periods of the plurality of load fluctuation periods. It is preferable that each is assigned to one of the plurality of load fluctuation periods and executed sequentially.

In the present invention, there are a plurality of load fluctuation periods, and at least one of the plurality of slave units is different from the first communication line and the first signal transmitted on the first communication line. A gateway device that performs protocol conversion between a third signal transmitted on a second communication line, and the gateway device includes a plurality of first signals when a data amount of the first signal is greater than a predetermined value. So that at least two of the plurality of third signals that are protocol-converted for each of the plurality of first signals are transmitted in different load fluctuation periods of the plurality of load fluctuation periods. It is preferable that each of the plurality of third signals is assigned to one of the plurality of load fluctuation periods and sequentially transmitted to the second communication line.

In this invention, before performing the state transition, an arbitrary first slave unit among the plurality of slave units requests the parent unit to permit the state transition, and the load designated by the parent unit It is preferable that the state transition is performed during a variation period, and the time length of the load variation period designated by the parent device is set by the parent device according to the contents of the state transition.

In this invention, the base unit holds data of current consumption in the state transition of each of the plurality of slave units in advance, and the load fluctuation is based on the current consumption of each of the plurality of slave units. The period is divided into a plurality of time regions, and each of the plurality of slave devices is assigned to one of the plurality of time regions so that the sum of the consumption currents of the plurality of time regions is equalized. It is preferable that an arbitrary first slave unit among the slave units performs the state transition in a time domain assigned to the first slave unit among the plurality of time domains.

In the present invention, the master unit includes a measurement unit that measures current consumption at the time of the state transition of each of the plurality of slave units, and is based on a measurement value of the current consumption of each of the plurality of slave units. Then, the load variation period is divided into a plurality of time regions, and each of the plurality of slave units is set to any one of the plurality of time regions so that the sum of the consumption currents of the plurality of time regions is equalized. Preferably, any one of the plurality of slave units performs the state transition in a time domain assigned to the first slave unit among the plurality of time domains.

In the present invention, the master unit communicates with each of the plurality of slave units using addresses assigned to the plurality of slave units, and the load variation period corresponds to each of the addresses. Dividing into a plurality of time regions, any one of the plurality of child devices is configured to perform the state transition in a time region corresponding to the address of the first child device among the plurality of time regions. It is preferable to carry out.

The communication terminal of the present invention is a communication terminal that is supplied with driving power via a communication line and sends a current signal to the communication line, and performs transmission processing using the current signal only during a communication period, and The present invention is characterized in that state transition accompanied by fluctuations in the driving power exceeding a predetermined width is performed only during a load fluctuation period different from the period.

1 is a block diagram illustrating a configuration of a communication system according to a first embodiment. FIG. 2 is a block diagram illustrating a configuration of a transmission parent device according to the first embodiment. 3 is a waveform diagram illustrating a format of a transmission signal of the communication system according to the first embodiment. 2 is a block diagram illustrating a configuration of a communication terminal according to Embodiment 1. FIG. It is a wave form diagram which shows the state transition of the communication terminal of Embodiment 1. It is a wave form diagram which shows the state transition of the monitor terminal of Embodiment 1. FIG. 3 is a block diagram illustrating a configuration of a functional unit of the monitor terminal according to Embodiment 1. FIG. It is a block diagram which shows another structure of the function part of the monitor terminal of Embodiment 1. FIG. It is a wave form diagram which shows another state transition of the monitor terminal of Embodiment 1. FIG. It is a wave form diagram which shows the state transition of the gateway apparatus of Embodiment 1. It is a wave form diagram which shows the state transition of the communication terminal of Embodiment 2. It is a sequence diagram which shows the state transition of the communication terminal of Embodiment 2. FIG. 10 is a block diagram illustrating a configuration of a transmission parent device according to a third embodiment. It is a sequence diagram which shows the state transition of the communication terminal of Embodiment 3. FIG. 10 is a block diagram illustrating a configuration of a transmission parent device according to a fourth embodiment. FIG. 10 is a block diagram illustrating a configuration of a communication system according to a fifth embodiment. It is a wave form diagram which shows the state transition of the communication terminal of Embodiment 5. It is a block diagram which shows the structure of the conventional communication system.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the communication system according to the following embodiment includes a transmission parent device 1 that is a parent device, and

communication terminals

2 and 2 that are a plurality of child devices, a monitor terminal 2a, and a gateway device 2b. This is a system connected to a communication line L1 which is one communication line.

The master unit (transmission master unit 1) supplies driving power to a plurality of slave units (

communication terminals

2 and 2, monitor terminal 2a, gateway device 2b) via the first communication line (communication line L1). The plurality of slave units (

communication terminals

2 and 2, monitor terminal 2a, gateway device 2b) each send a first signal, which is a current signal, to the first communication line (communication line L1).

A plurality of slave units (

communication terminals

2, 2, monitor terminal 2a, gateway device 2b) perform transmission processing using the first signal only during a communication period in synchronization with each other, and load fluctuations different from the communication period The state transition accompanied by the fluctuation of the driving power exceeding the predetermined width is performed only during the period.

The communication terminal 2 according to the following embodiment is a communication terminal that is supplied with driving power via the communication line L1 and transmits a current signal to the communication line L1. The communication terminal 2 is configured to perform a transmission process using the current signal only during a communication period, and to perform a state transition with a variation in the driving power exceeding a predetermined width only during a load variation period different from the communication period. Has been.

(Embodiment 1)
FIG. 1 shows a configuration of a communication system according to the present embodiment, in which a transmission parent device 1 constituting a parent device,

communication terminals

2 and 2, a monitor terminal 2a, and a gateway device 2b constituting a child device are in the same communication. It is connected to the line L1 (first communication line). The communication line L1 is a two-wire type having a pair of signal lines. The monitor terminal 2a and the gateway device 2b are a type of the communication terminal 2, and hereinafter, the

communication terminals

2 and 2, the monitor terminal 2a, and the gateway device 2b are collectively referred to as “communication terminal 2”.

As shown in FIG. 2, the transmission base unit 1 includes a communication unit 11 and an address storage unit 12. Information of each address of the communication terminal 2 is stored in the address storage unit 12, and the communication unit 11 performs communication control using each address of the communication terminal 2. And the communication part 11 sends out the transmission signal (2nd signal) which consists of a voltage waveform of the format shown in FIG. 3 with respect to the communication line L1. This transmission signal is a voltage signal, and is a bipolar (± 24V) time-division multiplexed signal having a voltage transmission period T1, a current transmission period T2, and a load fluctuation period T3 obtained by dividing one frame into three.

The voltage transmission period T1 is a time slot in which the transmission master unit 1 generates a voltage signal for transmitting data to the communication terminal 2, and the transmission master unit 1 performs pulse width modulation on a carrier composed of a pulse train of ± 24V. To transmit data. The predetermined pulse train at the start of the voltage transmission period T1 indicates the start of the frame of the transmission signal and constitutes a known synchronization pulse for the communication terminal 2 to synchronize.

The current transmission period T2 is a period in which a voltage of +24 V is generated, and is a time slot in which the transmission master unit 1 receives a superimposed signal described later from the communication terminal 2. That is, the current transmission period T2 is a period during which the communication terminal 2 is permitted to superimpose the superimposed signal on the transmission signal and transmit data to the transmission master unit 1. This current transmission period T2 corresponds to the communication period of the present invention.

The load fluctuation period T3 is a period in which a voltage of −24 V is generated, and is a time slot in which the transmission of the superimposed signal by the communication terminal 2 is prohibited and the state transition of the communication terminal 2 is permitted.

The transmission signal sent from the transmission base unit 1 onto the communication line L1 is a ± 24V bipolar, and is repeatedly sent out on the communication line L1, so that power is always supplied to the communication line L1 by the transmission signal. ing. Therefore, in this system, driving power can be supplied to the communication terminal 2 by using the transmission signal. However, since there is an upper limit to the power supplied by the transmission parent device 1, the power that can be supplied from the transmission parent device 1 to the communication terminal 2 connected to the communication line L1 is limited.

Next, the configuration of the communication terminal 2 will be described. Hereinafter, one communication terminal 2 that is an arbitrary first communication terminal (first slave unit) among the plurality of communication terminals 2 will be described. The configuration is the same as that of the first communication terminal.

As shown in FIG. 4, the communication terminal 2 includes a communication unit 21, an address storage unit 22, a function unit 23, and a power supply unit 24. The communication unit 21 receives a voltage signal from the transmission parent device 1 and further superimposes a superimposed signal (first signal) on the transmission signal, and transmits data to the transmission parent device 1. The function unit 23 has functions (such as a monitor function and a gateway function) unique to the communication terminal 2. Address information of the first communication terminal is stored in the address storage unit 22, and the function unit 23 matches the destination address included in the voltage signal received by the communication unit 21 with the address of the first communication terminal. For example, a predetermined operation corresponding to the voltage signal is executed. The power supply unit 24 rectifies the transmission signal supplied from the communication line L1 to generate driving power for the first communication terminal.

And in this embodiment, each time length of the voltage transmission period T1, the current transmission period T2, and the load fluctuation period T3 is determined in advance.

The communication unit 21 of the communication terminal 2 receives a transmission signal transmitted from the transmission parent device 1 on the communication line L1, and receives a voltage signal transmitted from the transmission parent device 1 in the voltage transmission period T1.

In addition, the communication unit 21 of the communication terminal 2 transmits data to the transmission parent device 1 by superimposing a superimposed signal on a transmission signal in the current transmission period T2. This superimposed signal is a current signal (first signal) for transmitting data by changing the current flowing on the communication line L1, and is a signal obtained by modulating a carrier wave having a frequency higher than that of the voltage signal.

Further, the functional unit 23 of the communication terminal 2 changes the state using the driving power generated by the power supply unit 24 in the load fluctuation period T3. For example, when the communication terminal 2 is the monitor terminal 2a (see FIG. 1), the function unit 23 is configured by an LCD device having a video display function, and the function unit 23 performs state transition such as on / off of the LCD backlight. Is performed in the load fluctuation period T3.

That is, the communication terminal 2 includes a communication unit 21 that performs transmission processing within a range in which fluctuations in driving power do not exceed a predetermined range, and a functional unit 23 that executes predetermined operations using the driving power. The communication terminal 2 performs the state transition by the operation state of the function unit 23 changing from the first state (for example, the LCD backlight is off) to the second state (for example, the LCD backlight is on). It is configured.

The plurality of communication terminals 2 configured in this way each receive a transmission signal that the transmission base unit 1 sends out on the communication line L1, and synchronize with each other by the above-described synchronization pulse of the voltage transmission period T1, and the voltage transmission period T1, current transmission period T2, and load fluctuation period T3 can be set. That is, the plurality of communication terminals 2 can set the voltage transmission period T1, the current transmission period T2, and the load fluctuation period T3 at the same timing.

Next, as an operation example of the state transition of the communication terminal 2, the operation of the monitor terminal 2a will be described with reference to FIG. FIG. 5 shows a waveform of a signal transmitted on the communication line L1.

The monitor terminal 2a receives the voltage signal transmitted by the transmission parent device 1 in the voltage transmission period T1. In the current transmission period T2, the communication terminal 2 superimposes the superimposed signal P on the transmission signal and transmits data to the transmission parent device 1.

Then, when the LCD backlight of the monitor terminal 2a is off, it is assumed that the transmission base unit 1 transmits a backlight on request using a voltage signal in the voltage transmission period T1 (time t1). The monitor terminal 2a changes the state of the LCD backlight from off (first state) to on (second state) in the load variation period T3 within the same frame as the voltage transmission period T1 that has received the backlight on request (time). t2).

That is, the communication terminal 2 such as the monitor terminal 2a sets the current transmission period T2 in which the communication terminal 2 transmits the superimposed signal P as a different period from the load fluctuation period T3 in which the state of the functional unit 23 is changed. Therefore, even if the fluctuation (load fluctuation) of the current flowing on the communication line L1 becomes large due to the state transition of the communication terminal 2 (LCD backlight ON / OFF, etc.), the superimposed signal P composed of the current signal is distorted. Transmission errors can be suppressed without occurring.

Thus, in this embodiment, even if it is the structure which supplies drive power from the transmission main | base station 1 to the communication terminal 2 via the communication line L1, and the communication terminal 2 communicates using an electric current signal, workability | operativity is improved. Transmission errors can be suppressed without deteriorating.

In addition, the communication terminal 2 performs state transition by executing a control sequence. When the time length of one control sequence is longer than the time length of the load fluctuation period T3, the functional unit 23 of the communication terminal 2 divides one control sequence into a plurality of control sequences. The communication terminal 2 executes each of the plurality of control sequences in the plurality of load fluctuation periods T3 so that at least two of the plurality of divided sequences are executed in different load fluctuation periods T3 among the plurality of load fluctuation periods T3. Allocate to either and execute sequentially.

Hereinafter, the state transition of the monitor terminal 2a will be described with reference to FIG. FIG. 6 shows a waveform of a signal transmitted on the communication line L1.

First, as shown in FIG. 7, the function unit 23 of the monitor terminal 2a includes an LCD controller 23a and an LCD backlight 23b. When the LCD controller 23a is off and the LCD backlight 23b is off, it is assumed that the transmission master 1 transmits a backlight on request using a voltage signal in the voltage transmission period T1 (time t11). The control sequence for performing the backlight on operation of the monitor terminal 2a can be divided into a first sequence for switching the LCD controller 23a from off to on and a second sequence for switching the LCD backlight 23b from off to on. Therefore, the monitor terminal 2a changes the state of the LCD controller 23a from off to on in the load variation period T3 in the same frame as the voltage transmission period T1 that has received the backlight on request (time t12). Next, the monitor terminal 2a changes the state of the LCD backlight 23b from off to on in the load fluctuation period T3 in the next frame (time t13).

Therefore, the communication terminal 2 can divide and execute one control sequence over a plurality of load fluctuation periods T3, so there is no need to increase the time length of the load fluctuation period T3, and the load fluctuation period T3 is increased. This can suppress a decrease in transmission efficiency.

Next, when the functional unit 23 of the monitor terminal 2a includes an LCD controller 23a, an LCD backlight 23b, a transmission CPU 23c, a video processing CPU 23d, and an audio processing CPU 23e as shown in FIG. 8, the monitor terminal 2a 9 state transition is performed. FIG. 9 shows a waveform of a signal transmitted on the communication line L1.

In this case, the control sequence for performing the backlight on operation of the monitor terminal 2a can be divided into four sequences. In the first sequence, the transmission CPU 23c is activated from the sleep state, and in the second sequence, the video processing CPU 23d and the audio processing CPU 23e are activated from the sleep state. The third sequence switches the LCD controller 23a from off to on, and the fourth sequence switches the LCD backlight 23b from off to on.

First, when the LCD controller 23a is off, the LCD backlight 23b is off, the transmission CPU 23c is off, the video processing CPU 23d is off, and the audio processing CPU 23e is off, the transmission master unit 1 uses the voltage signal in the voltage transmission period T1. Assume that a backlight on request has been transmitted (time t21). The monitor terminal 2a activates the transmission CPU 23c from the sleep state during the load fluctuation period T3 within the same frame as the voltage transmission period T1 that has received the backlight on request (time t22). Then, the monitor terminal 2a activates the video processing CPU 23d and the audio processing CPU 23e from the sleep state during the load fluctuation period T3 in the next frame (time t23). Next, the monitor terminal 2a changes the state of the LCD controller 23a from off to on in the load fluctuation period T3 in the next frame (time t24). Next, the monitor terminal 2a changes the state of the LCD backlight 23b from off to on in the load fluctuation period T3 in the next frame (time t25).

In this case as well, the communication terminal 2 divides and executes one control sequence over a plurality of load fluctuation periods T3, and can suppress a decrease in transmission efficiency due to an increase in the load fluctuation period T3.

Next, as an operation example of the state transition of the communication terminal 2, the operation of the gateway device 2b (see FIG. 1) will be described with reference to FIG. The functional unit 23 of the gateway device 2b performs signal protocol conversion between the communication line L1 (first communication line) and the communication line L2 (second communication line). Specifically, the functional unit 23 of the gateway device 2b converts the superimposed signal P (first signal) transmitted on the communication line L1 into a signal (third signal) of another communication protocol transmitted on the communication line L2. Converted and sent out on the communication line L2. Further, the functional unit 23 of the gateway device 2b converts a signal of another communication protocol transmitted through the communication line L2 into a superimposed signal P, and sends the signal onto the communication line L1. Then, the functional unit 23 of the gateway device 2b performs a protocol-converted signal transmission operation (state transition operation) in the load fluctuation period T3. The signal transmitted through the communication line L2 is generated using a communication protocol such as RS485, RS422, Ethernet (registered trademark).

FIG. 10 shows a signal waveform on communication line L1 (“on communication line L1”) and a signal waveform (“on communication line L2”) that has been protocol-converted by gateway device 2b and sent onto communication line L2. ing. When the data amount of the superimposed signal P to be protocol-converted is larger than a predetermined value that can be transmitted in one load fluctuation period T3, the functional unit 23 of the gateway device 2b divides the superimposed signal P into a plurality of pieces. To do. The functional unit 23 of the gateway device 2b converts each of the divided superimposed signals (first signals) P into a third signal of another communication protocol. The gateway device 2b transmits each of the plurality of third signals to the plurality of load fluctuation periods T3 so that at least two of the plurality of third signals are transmitted in different load fluctuation periods T3 of the plurality of load fluctuation periods T3. Are sequentially transmitted to the communication line L2. In the example of FIG. 10, the superimposed signal (first signal) P is divided into two, and the two signals (third signal) after the protocol conversion are respectively assigned to the load variation periods T3 of two different frames for communication. Sending to line L2.

Therefore, load fluctuation due to the transmission operation (state transition operation) of the gateway device 2b occurs only in the load fluctuation period T3, so that transmission errors can be suppressed without causing distortion in the superimposed signal P made up of current signals. it can. Further, since the gateway device 2b can divide and transmit a signal over a plurality of load fluctuation periods T3, it is not necessary to lengthen the time length of the load fluctuation period T3, and by extending the load fluctuation period T3. A decrease in transmission efficiency can be suppressed.

(Embodiment 2)
The communication system of the present embodiment has the same configuration as that of the first embodiment, and the same components are denoted by the same reference numerals and description thereof is omitted.

11 and 12, the state transition of an arbitrary first communication terminal (first slave unit) among the plurality of communication terminals 2 will be described. FIG. 11 shows a waveform of a signal transmitted on the communication line L1, and FIG. 12 shows a communication sequence.

First, the communication unit 21 of the communication terminal 2 transmits the load variation request S1 to the transmission parent device 1 using the superimposed signal P in the current transmission period T2 before the function unit 23 performs state transition (time t31). . That is, the communication terminal 2 requests permission of the state transition from the transmission parent device 1 before performing the state transition of the first communication terminal. In addition, the communication unit 21 of the communication terminal 2 adds information on the length of time required for the state transition of the function unit 23 to the load change request S1.

The communication unit 11 of the transmission base unit 1 uses the voltage signal to the communication terminal 2 that is the transmission source of the load variation request S1 in the voltage transmission period T1 of the frame that permits state transition (in this case, the next frame). Is sent (time t32). The transmission base unit 1 adds information on the length of the load fluctuation period T3 to the fluctuation permission notification S2. The time length of the load fluctuation period T3 specified by the fluctuation permission notification S2 is set longer than the time length required for the state transition based on the load fluctuation request S1 received by the transmission parent device 1. Furthermore, the transmission parent device 1 adjusts the time length of the load fluctuation period T3 of the frame that permits state transition to the above-specified time length.

The functional unit 23 of the communication terminal 2 that is the transmission source of the load fluctuation request S1 performs the state transition S3 in the load fluctuation period T3 in the same frame as the voltage transmission period T1 that has received the fluctuation permission notification S2 (t33).

Accordingly, the transmission parent device 1 can dynamically assign the communication terminal 2 the load variation period T3 used for state transition and the time length of the load variation period T3 according to the contents of the state transition. Become. That is, it is possible to efficiently use the load fluctuation period T3 and improve control responsiveness in the load fluctuation period T3.

(Embodiment 3)
In the communication system of the present embodiment, the transmission parent device 1 includes a current data storage unit 13 as shown in FIG. The current data storage unit 13 stores in advance data of current consumption required for each communication terminal 2 at the time of state transition.

Then, the transmission base unit 1 divides the load fluctuation period T3 into a plurality of time regions based on the respective current consumptions of the communication terminals 2, and the sum (maximum value) of the respective current consumptions in the time regions is even. Each communication terminal 2 is assigned to any time region so as to be (grouping). An arbitrary first communication terminal (first slave) among the plurality of communication terminals 2 performs state transition in a time domain assigned to the first communication terminal among the plurality of time domains.

Specifically, the current data storage unit 13 of the transmission parent device 1 stores in advance the current consumption data “communication terminal 2A: 100 mA, communication terminal 2B: 500 mA, communication terminal 2C: 400 mA” of the communication terminal 2 alone shown in Table 1. I remember it. The data of current consumption of the communication terminal 2 alone is data of current consumed inside the communication terminal 2 without considering a loss due to a voltage drop of the communication line L1.

Then, as shown in FIG. 14, the transmission base unit 1 divides the load fluctuation period T3 into two time regions D1 and D2, assigns one communication terminal 2B to the time region D1, and sets two in the time region D2. The communication terminals 2A and 2C are grouped. FIG. 14 shows a waveform of a signal transmitted on the communication line L1.

The communication unit 11 of the transmission base unit 1 transmits the above grouping result to each of the communication terminals 2A to 2C using the voltage signal of the voltage transmission period T1 when it starts up, and the communication terminals 2A to 2C Each can recognize the time domain assigned to each. Then, each of the communication terminals 2A to 2C performs state transition in the time domain assigned to each within the load fluctuation period T3. That is, the sum of current consumption in the time domain D1 (maximum value) is 500 mA, the sum of current consumption in the time domain D2 (maximum value) is 500 mA, and the sum of the current consumption in each of the time domains D1 and D2 Value) are equal to each other.

Therefore, it is possible to evenly allocate the driving power of the communication terminal 2 necessary for the state transition within the load fluctuation period T3, and the power supplied from the transmission parent device 1 can be efficiently used in the load fluctuation period T3. Moreover, since the peak value of the driving power supplied from the transmission parent device 1 to the communication line L1 can be suppressed, the power feeding circuit of the transmission parent device 1 can be configured at low cost.

(Embodiment 4)
In the communication system of the present embodiment, the transmission parent device 1 includes a current measurement unit 14 and a current data storage unit 15 as shown in FIG.

The current measuring unit 14 actually measures the current consumption of each communication terminal 2 by measuring the current supplied from the transmission parent device 1 to the communication line L1. Specifically, after the transmission master unit 1 is activated, the current measurement unit 14 sequentially transmits an operation request to each of the communication terminals 2 using the voltage signal in the voltage transmission period T1. The functional unit 23 of the communication terminal 2 that has received the operation request executes state transition such as sleep and activation in the load fluctuation period T3. The current measuring unit 14 measures the current consumption of the communication terminal 2 when the functional unit 23 of the communication terminal 2 executes state transition. The current measuring unit 14 sequentially transmits an operation request to each of the communication terminals 2 to measure each consumption current supplied at the time of the state transition of the subordinate communication terminal 2 and stores the measurement result in the current data storage unit 15. .

Specifically, the current data storage unit 15 of the transmission base unit 1 stores current consumption measurement data “communication terminal 2A: 150 mA, communication terminal 2B: 550 mA, communication terminal 2C: 700 mA” shown in Table 2. Then, as shown in FIG. 14, the transmission master unit 1 divides the load fluctuation period T3 into two time regions D1 and D2, allocates two communication terminals 2A and 2B to the time region D1, and assigns them to the time region D2. Grouping is performed in which one communication terminal 2C is allocated.

That is, the transmission base unit 1 divides the load variation period T3 into a plurality of time regions based on the actual current consumption of each of the communication terminals 2, and the sum (maximum value) of the current consumptions in the time regions is calculated. The communication terminals 2 are assigned to any time region so as to be even. An arbitrary first communication terminal (first slave) among the plurality of communication terminals 2 performs state transition in a time domain assigned to the first communication terminal among the plurality of time domains.

The communication unit 11 of the transmission base unit 1 transmits the above grouping result to each of the communication terminals 2A to 2C using the voltage signal of the voltage transmission period T1, and each of the communication terminals 2A to 2C The assigned time domain can be recognized. Then, each of the communication terminals 2A to 2C performs state transition in the time domain assigned to each within the load fluctuation period T3. That is, the sum of current consumption in the time domain D1 (maximum value) is 700 mA, the sum of current consumption in the time domain D2 (maximum value) is 700 mA, and the sum of the current consumption in the time domains D1 and D2 is equal to each other. Become.

The actual drive power supplied by the transmission master unit 1 is a combination of the power consumption of the communication terminal 2 alone and the power loss in the communication line L1 from the transmission master unit 1 to the communication terminal 2. Therefore, in the present embodiment, the current supplied from the transmission base unit 1 to the communication line L1 at the time of the state transition of the communication terminal 2 is measured, and either communication terminal 2 is selected based on the actual current consumption of each communication terminal 2. Assigned to the time domain. That is, the grouping can be performed in consideration of the influence of the system configuration such as the loss due to the voltage drop of the communication line L1, and the power (maximum value) supplied from the transmission master unit 1 to the communication line L1 in each time domain. Each communication terminal 2 can be assigned to any time region so as to be even.

Therefore, it is possible to evenly allocate the driving power of the communication terminal 2 necessary for the state transition within the load fluctuation period T3 based on the actual current consumption. In the load fluctuation period T3, the power supplied to the transmission master unit 1 is reduced. It can be used more efficiently. In addition, since the peak value of the driving power supplied from the transmission parent device 1 to the communication line L1 can be more reliably suppressed, the power supply circuit of the transmission parent device 1 can be configured at low cost.

(Embodiment 5)
FIG. 16 shows a configuration of a communication system according to the present embodiment, and the communication terminal 2 includes a transmission terminal 2c and a superimposition terminal 2d. In addition, the same code | symbol is attached | subjected to the structure similar to Embodiment 1, and description is abbreviate | omitted. Hereinafter, when the transmission terminal 2c and the superposition terminal 2d are not distinguished, they are referred to as communication terminals 2.

The communication protocol is different between the communication signal transmitted through the communication line L1 in the communication between the transmission parent device 1 and the communication terminal 2 and the communication signal transmitted through the transmission line L1 in the communication between the overlapping terminals 2d. Yes. The former communication signal is a pulse-width-modulated bipolar signal, and the latter communication signal uses a current signal obtained by modulating a carrier wave having a frequency higher than that of the former communication signal. Hereinafter, the former communication signal is referred to as a “transmission signal”, and the latter communication signal is referred to as a “superimposition signal”.

The communication unit 21 of the transmission terminal 2c has a transmission / reception function for transmission signals, and the communication unit 21 of the superimposition terminal 2d has transmission / reception functions for transmission signals and superimposition signals.

A transmission signal used in communication between the transmission parent device 1 and the communication terminal 2 has a predetermined format, and the transmission parent device 1 repeatedly sends it to the communication line L1. Each communication terminal 2 has an address (identification information). By including the address of the communication terminal 2 in the transmission signal transmitted by the transmission master unit 1, the communication terminal 2 is designated and transmitted from the transmission master unit 1. Instructions to each terminal are given. That is, an instruction can be individually given from the transmission base unit 1 to the communication terminal 2 by time division multiplexing. The transmission signal is provided with a period during which information is notified from the communication terminal 2 to the transmission master unit 1.

The transmission terminal 2 c is connected to a monitoring terminal that receives a monitoring input from a switch or a sensor (not shown) and requests the transmission master 1 to control the load, and a load (not shown) is connected to the transmission terminal 1. There are two types of control terminals that control the load in accordance with instructions from.

The transmission base unit 1 includes a relation table that associates switches or sensors (hereinafter, the switches and sensors are collectively referred to as monitoring means) and loads. By registering the relation between the monitoring means and the load in the relation table in advance, the transmission master unit 1 controls the load associated with the monitoring means in the relation table according to the switch operation or the change in the sensor output. To do. The relation table may include the contents of load control for the monitoring means.

As shown in FIG. 17, the transmission signal (second signal) includes a synchronization pulse period T11, a transmission period T12, a return period T13, an interrupt period T14, a short-circuit detection period T15, and a pause period T16. And a bipolar (± 24V) signal. The transmission master unit 1 repeatedly transmits this transmission signal.

The synchronization pulse period T11 indicates the start of the frame of the transmission signal, and has two periods with different voltage polarities. The voltage polarity changes from + 24V to −24V within the period of the synchronization pulse period T11.

The transmission period T12 is a period in which an instruction is transmitted from the transmission parent device 1 to the communication terminal 2, and is a time slot in which the transmission parent device 1 generates a voltage signal for transmitting data to the communication terminal 2. The transmission base unit 1 transmits data by performing pulse width modulation on a carrier composed of a pulse train of ± 24V. This voltage signal includes mode information indicating the type of transmission signal, an address for individually specifying the communication terminal 2, and control information indicating the content of the instruction.

The return period T13 is a period in which a voltage of + 24V is generated and information is notified from the communication terminal 2 to the transmission parent device 1, and the transmission parent device 1 waits without transmitting a signal.

The interrupt period T14 is a period for generating a voltage of −24V and detecting an interrupt signal output from the communication terminal 2, and the short-circuit detection period T15 is generating a voltage of + 24V and generating a communication line This is a period for detecting a short circuit of L1. The idle period T16 is a period in which a voltage of -24V is generated and data transmission is not performed.

Each communication terminal 2 performs an operation based on the control information included in the transmission period T12 when its own address is included in the address included in the transmission period T12 of the transmission signal received via the communication line L1. . For example, in the case of a control terminal, since the control content for the load is included in the control information of the transmission signal, the load is controlled according to the control content. The switch operation in the monitoring terminal and the load control result in the control terminal are returned to the transmission master unit 1 by a current mode signal (current signal) in synchronization with the return period T13 (corresponding to the communication period of the present invention). The

The current mode signal (first signal) is a binary current signal represented by a state where the communication lines L1 are opened and a state where the communication lines L1 are short-circuited via a low impedance element. . For example, the communication terminal 2 has a return circuit in which a return transistor and a resistor are connected in series, and turns on and off the return transistor in a state where a DC voltage obtained by rectifying a transmission signal is applied to the return circuit. Thereby, the magnitude of the current flowing from the communication line L1 to the communication terminal 2 changes, and the communication terminal 2 can generate a current signal on the communication line L1 and transmit the current signal to the transmission master unit 1. .

The transmission base unit 1 always performs polling for sequentially accessing the communication terminal 2 by cyclically changing the address of the communication terminal 2 included in the transmission signal. In the case of constant polling, the communication terminal 2 whose address included in the transmission signal matches its own address operates if the transmission signal includes control information, and takes control information and returns its operating state. In the period T13, it is returned to the transmission master unit 1.

Incidentally, the communication terminal 2 generates an interrupt signal I on the communication line L1 in synchronization with the transmission signal interrupt period T14 when a monitoring input or the like is generated (see FIG. 17). For example, when the monitoring terminal receives a monitoring input from the switch, the monitoring terminal generates an interrupt signal I in the interrupt period T14. When the transmission base unit 1 detects this interrupt signal I, it searches for the communication terminal 2 that generated the interrupt signal I, and accesses the communication terminal 2 to obtain the address of the communication terminal 2.

When the address of the communication terminal 2 that generated the interrupt signal I is acquired by the transmission base unit 1, the transmission base unit 1 designates the address and causes the communication terminal 2 to return data such as monitoring input. Based on the monitoring input returned from the communication terminal 2, the transmission master unit 1 generates a transmission signal including control information for the communication terminal 2 provided with a load associated with each monitoring input in advance by the relation table. It is sent to the communication line L1. Therefore, the load is controlled in accordance with a request (switch operation or the like) from the communication terminal 2 that has generated the interrupt signal I.

As described above, the transmission base unit 1 always performs polling at all times and sequentially accesses all the communication terminals 2. When receiving the interrupt signal from any one of the communication terminals 2, the transmission master unit 1 accesses the communication terminal 2 that generated the interrupt signal I and receives a request from the communication terminal 2. In this way, polling is always performed, and when an interrupt signal I is generated, an operation for preferentially processing a request from the communication terminal 2 that has generated the interrupt signal I is referred to as interrupt polling.

On the other hand, the superimposing terminal 2d is, for example, a measuring terminal that measures the amount of power consumed by the load, a monitor terminal that displays the measurement result of the measuring device, or the like. The superimposing terminal 2d performs communication using the above-described constant polling and interrupt polling with the transmission master unit 1, and the superimposing terminals 2d communicate with each other using a superimposing signal transmitted on the communication line L1. For example, the monitor terminal collects the measurement results of the measurement terminal.

For the communication between the superimposition terminals 2d, a superimposition signal P that is superimposed on the transmission signal and transmitted through the communication line L1 is used. Specifically, the superimposed signal P is transmitted in a superimposable period (corresponding to the communication period of the present invention) appropriately selected from the synchronization pulse period T11 and the pause period T16 of the transmission signal. The superimposed signal P (first signal) is a current signal for data transmission by changing the current flowing on the communication line L1, and is a signal obtained by modulating a carrier wave having a frequency higher than that of the voltage signal.

Furthermore, since the transmission signal sent from the transmission master unit 1 onto the communication line L1 is multipolar and is always polled, power is constantly supplied to the communication line L1 by the transmission signal. Therefore, in this system, driving power can be supplied to the communication terminal 2 by using the transmission signal. However, since there is an upper limit to the power supplied by the transmission parent device 1, the power that can be supplied from the transmission parent device 1 to the communication terminal 2 connected to the communication line L1 is limited.

The communication terminal 2 is in a state such as activation / sleep of the communication terminal 2 by communication with the transmission master unit 1 using the above-described constant polling and interrupt polling, and communication between the overlapping terminals 2d performed using the superimposed signal P. Transition is indicated. Each functional unit 23 of the communication terminal 2 instructed to change the state changes the state using the driving power generated by the power supply unit 24 in the short circuit detection period T15. That is, the short circuit detection period T15 also serves as the load fluctuation period of the present invention.

For example, when the superimposing terminal 2d is a monitor terminal, the functional unit 23 is configured by an LCD device having a video display function, and the functional unit 23 performs a state transition such as on / off of the LCD backlight in a short circuit detection period T15. To do.

In addition, as shown in FIG. 17, the transmission master unit 1 divides the short-circuit detection period T15 into the same number of time regions D11, D12,..., D1n as the addresses of the

subordinate communication terminals

2, and 1 is assigned to each time region. All communication terminals 2 are assigned. An arbitrary first communication terminal (first slave unit) among the plurality of communication terminals 2 is in a state in the time domain assigned to the first communication terminal among the plurality of time domains D11, D12,. Make a transition.

The process of assigning the time domain to the communication terminal 2 is automatically performed when the transmission master unit 1 performs the address setting process of the communication terminal 2. Therefore, since the address setting process and the time domain allocation process can be performed simultaneously, for example, a communication sequence for allocating the time domain becomes unnecessary. That is, the cost increase due to the addition of a circuit such as a current measurement unit can be suppressed without increasing the number of steps for assigning the time domain.

When the address of the communication terminal 2 is set, the communication unit 11 of the transmission parent device 1 transmits the above time domain assignment result to each of the communication terminals 2 using the voltage signal of the voltage transmission period T1, and the communication terminal 2 Each can recognize the time domain assigned corresponding to each address. And each of the communication terminals 2 performs a state transition in the time area | region allocated to each of the short circuit detection period T15.

Therefore, in the short circuit detection period T15, it is possible to prevent the state transitions of the communication terminals 2 from concentrating at the same timing, and to control the load fluctuation in the load fluctuation period T3 to be substantially constant, thereby efficiently using the load fluctuation period T3. Can do. Moreover, since the peak value of the driving power supplied from the transmission parent device 1 to the communication line L1 can be suppressed, the power feeding circuit of the transmission parent device 1 can be configured at low cost.

Claims

A master unit and a plurality of slave units are connected to a first communication line, the master unit supplies driving power to the plurality of slave units via the first communication line, and the plurality of slave units are respectively Sending a first signal which is a current signal to the first communication line;
The plurality of slave units perform transmission processing using the first signal only during a communication period in synchronization with each other, and the fluctuation of the driving power exceeds a predetermined width only during a load fluctuation period different from the communication period. A communication system characterized by being configured to perform state transition.
Each of the plurality of slave units includes a communication unit that performs the transmission processing within a range in which the fluctuation of the driving power does not exceed the predetermined width, and a functional unit that executes a predetermined operation using the driving power. The communication system according to claim 1, wherein the state transition is performed when the operation state of the functional unit transitions from a first state to a second state.
The base unit sends a second signal to the first communication line, and the second signal is a time-division voltage obtained by dividing one frame into a plurality of time zones including the communication period and the load fluctuation period. Signal,
The plurality of slave units each operate using the second signal as the driving power, and set the communication period and the load variation period based on the received second signal, respectively. Item 3. The communication system according to item 1 or 2.
There are a plurality of load fluctuation periods,
The plurality of slave units perform the state transition by executing a control sequence, and when the time length of the control sequence is longer than the time length of the load fluctuation period, the control sequence is changed to a plurality of control sequences. Dividing, and assigning each of the plurality of control sequences to one of the plurality of load fluctuation periods so that at least two of the plurality of sequences are executed in different load fluctuation periods of the plurality of load fluctuation periods. 4. The communication system according to claim 1, wherein the communication system is sequentially executed.
There are a plurality of load fluctuation periods,
At least one slave unit among the plurality of slave units includes a first signal transmitted on the first communication line and a third signal transmitted on a second communication line different from the first communication line. It is a gateway device that performs protocol conversion between each other,
When the data amount of the first signal is greater than a predetermined value, the gateway device divides the first signal into a plurality of first signals, and a plurality of third signals obtained by performing protocol conversion for each of the plurality of first signals. Each of the plurality of third signals is assigned to one of the plurality of load fluctuation periods so that at least two of the plurality of load fluctuation periods are transmitted in different load fluctuation periods. The communication system according to claim 1, wherein the communication system is sequentially transmitted.
An arbitrary first child machine out of the plurality of child machines requests permission of the state transition from the parent machine before performing the state transition, and the load change period specified by the parent machine The state transition is performed, and the time length of the load variation period designated by the parent device is set by the parent device according to the contents of the state transition. Communication system.
The master unit holds data of current consumption in the state transition of each of the plurality of slave units in advance, and sets the load fluctuation period to a plurality of times based on the current consumption of each of the plurality of slave units. Dividing each of the plurality of slave units into one of the plurality of time regions so that the sum of the current consumption of each of the plurality of time regions is equalized.
The arbitrary first slave unit among the plurality of slave units performs the state transition in a time domain assigned to the first slave unit among the plurality of time domains. The communication system according to any one of 1 to 5.
The master unit includes a measurement unit that measures current consumption at the time of the state transition of each of the plurality of slave units, and the load based on the measurement value of the current consumption of each of the plurality of slave units Dividing the variable period into a plurality of time regions, and assigning each of the plurality of slave units to any of the plurality of time regions so that the sum of the consumption current of each of the plurality of time regions becomes equal,
The arbitrary first slave unit among the plurality of slave units performs the state transition in a time domain assigned to the first slave unit among the plurality of time domains. The communication system according to any one of 1 to 5.
The master unit communicates with each of the plurality of slave units using addresses assigned to the plurality of slave units, and the load variation period is a plurality of time regions corresponding to the respective addresses. Divided into
An arbitrary first slave unit among the plurality of slave units performs the state transition in a time domain corresponding to the address of the first slave unit among the plurality of time domains. Item 6. The communication system according to any one of Items 1 to 5.
A communication terminal that is supplied with drive power via a communication line and sends a current signal to the communication line,
It is configured to perform transmission processing using the current signal only during a communication period, and to perform state transition accompanied by fluctuations in the driving power exceeding a predetermined width only during a load fluctuation period different from the communication period. A characteristic communication terminal.