JPH01261051A - Transmission control method - Google Patents

Abstract

PURPOSE:To obtain the synchronizing signal of a main text with sufficient time accuracy by sending a pre-text with intermittent amplitude modulation to a carrier modulated by a synchronizing signal to receive the main text, allowing a reception means to detect the synchronizing signal from the pre-text sent by a transmission means to receive the main text. CONSTITUTION:In the case of sending a pre-text data 33, every time a synchronizing pulse 34 generated by a synchronizing signal generating means 30 for main text is generated, a carrier 35 whose phase is inverted by 180 deg. is subjected to 100% amplitude modulation intermitting the transmission in the timing based on the time limit of a synchronizing signal 36 obtained from a power supply synchronizing signal generating means 24 and the result is outputted from an amplitude modulation means 32 to a bus 4. Then a main text data 37 is subjected to phase modulation in matching with a synchronizing signal 34 obtained from a main text synchronizing signal generating means 30 to output the result to the bus 4. Then a reception means 23 detects a synchronizing signal 44 from the pre-text sent by the transmission means 20 to receive the main text. Thus, the synchronizing signal 44 with sufficient accuracy is obtained even from the communication of the high speed main text.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a transmission control method for a plurality of terminals that transmit signals to each other via a path.

Conventional technology inventors have proposed a system for transmitting data at high speed by changing the modulation formula of the preamble and main text of a message to avoid collisions, as shown in Figures 4, 6, 6, and 7. We are proposing a method. In the figure, 1, 2, and 3 are terminals each equipped with a transmitting means and a receiving means, and are connected to a path 4 that also serves as an AC power line in a general household. Receiving the sent signal. 1' in Figure 6,
2'.

◎6 is the voltage waveform of the commercial frequency on the bus 4 which also serves as the AC power line in Figure 4. If the carrier wave signal is in the first half of the half cycle of voltage 6 of the commercial frequency, it represents data 0, and if it is in the second half, it represents data 1, and the 3 bits in the preamble and the main sentence represent one unit of message. do. Terminal 1 sends "000" to terminal 2
Terminal 3 attempts to transmit @Oo1# with ``1oO#'' as a preamble. In this case, in order to avoid signal collision on path 4, each terminal transmits @Oo1# on bus 4. If there is already a signal, the terminal is configured to wait until the end of this signal before sending its own signal.In other words, the terminal 3 tried to send a signal "1" using its own transmission means, but Its receiving means receives the signal 1o# transmitted from the terminals 1 and 2 on the bus 4.

Because it is receiving data, it is not possible to send 0. In other words, it can actually be sent only after terminals 1 and 2 have finished transmitting, as shown in 3'.Similarly, terminal 2 is in 0 As shown, the first two bits "Oo" can be transmitted, but since "0#" is received in the third bit, the transmission is stopped. Transmission is restarted only after terminal 1 finishes transmitting. The actually used telegram has the structure shown in Figure 6. 06 is the security signal and other signals of zero,
07 is the priority code that indicates the urgency of the signal and is expressed as 2 bits. 07 is the address that indicates the source and is expressed as 8 bits. 08 is the address that indicates the destination and is 8 bits. 9 is the common code that indicates the data. 1o is a 2-bit control code that indicates whether the control code is unique to the manufacturer or is uniquely defined by the manufacturer, etc. 1o is a 2-bit system code that represents the manufacturer if the control code is unique to the manufacturer, and 11 is the name of your home. 12 is a 2-bit code that represents the length of data 13, 13 is 8 to 32 bits of data, 14
is a frame check code for checking whether there is an error in the message just sent, each expressed in 4 bits. The priority code 6 and sender address code 7 constitute the preamble of the message, and the following codes 8 to 14 constitute the main text of the message.0 Of these, the preamble is as explained using FIG. In order to avoid collisions when multiple terminals start transmitting at the same time, amplitude modulation is used to transmit. In this case, the source address code 7 is set for each terminal 1, 2, and 3. Therefore, collisions can always be detected during preamble transmission.Therefore, there is no need to consider collisions for the main text sent after the preamble has been sent, so modulation methods that can transmit data at high speed, such as frequency modulation and phase modulation, are It is used.

In this case, each terminal 1, 2, and 3 is configured to obtain the synchronization signal used for communication from the commercial frequency of path 4, so that even if the data transmission speed is high or the main text is high, the terminals 1, 2, and 3 receive the synchronization signal in synchronization with the voltage of the commercial frequency. Was. However, in this case, the power waveform was distorted by the inductive load and capacitive load connected to the AC power line, and the synchronization signal used for 1 communication could not have sufficient accuracy. This situation is shown in Figure 7. ◎6 is the voltage waveform of the commercial frequency power supply, and 16 is the synchronization signal obtained from the voltage waveform 6.◎6 and 16'
are a power supply waveform and a synchronization signal whose waveforms are distorted by the load equipment, respectively. As you can understand, the degree of waveform distortion varies depending on the location even within the same house.
．． The time position of the synchronization signal will differ depending on the connection position of step 3. When measured with an actual power supply, this error will be up to 600~e
It will be ooμ seconds. Furthermore, from the terminal that transmits the data,
The delay time for the signal to travel to the receiving terminal is about 60 microseconds at maximum, and this time is added to the error time of the synchronization signal.

These time errors can be ignored when communicating the preamble with a slow data transmission rate (1oO baud), but when communicating the main message with a fast data transmission rate (1200 baud), errors in the synchronization signal due to power signal distortion have a large effect. .

For example, data may be received as one bit from midway through a change point in the data, or data may be decoded with a complete shift of one pit, causing reception errors.◎Data transmission speed of main text If the speed is even faster than 960o baud, the signal transmission delay time cannot be ignored. Problems to be Solved by the Invention In the transmission control device of the above-mentioned type, the accuracy of the synchronization signal of the main message transmitted at high speed is There was a problem to be solved that it was not possible to obtain sufficient amount of water. The present invention solves this problem and provides a transmission control method that can obtain synchronization signals with sufficient accuracy even for high-speed main message communication.

Means for Solving the Problems The present invention comprises a plurality of terminals each having a transmitting means and a receiving means connected to a path, and a message outputted from the transmitting means consists of a preamble and a main message sent after the preamble. , the preamble is a synchronization signal for receiving the main text, and a carrier wave that has been subjected to phase modulation, amplitude phase modulation, frequency modulation, or amplitude frequency modulation is further intermittently subjected to amplitude modulation and transmitted, and the main text is the synchronization signal in the preamble. The transmission control method is such that the receiving means detects a synchronization signal from the preamble transmitted by the transmitting means and receives the main sentence.

Effect: By using the transmission control method described above, the synchronization signal of the main sentence can be obtained with sufficient time accuracy.

Embodiment FIG. 1 is a block diagram showing an embodiment of a device using the transmission control method of the present invention. Terminal IJB to path 4, 1
9 is connected. Each terminal has the same configuration,
Transmission means 20, 21. It consists of receiving means 22.23, power synchronization signal generation means 24.25, data creation means 26.27, and data execution means 28.29. When the transmitting means 2o transmits the preamble data 33 consisting of the main sentence synchronization signal generation means 30, the phase modulation means 31, and the amplitude modulation means 32, a synchronization pulse 34 generated by the main sentence synchronization signal generation means 3o is generated. The carrier wave 36, whose phase is inverted by 180° each time, is transmitted to the power synchronization signal generation means 24 by applying 100% amplitude modulation to intermittent transmission at a timing based on the time limit of the synchronization signal 3e obtained by the power supply synchronization signal generation means 24. The zero-order main sentence data 37 output to path 4 is phase-modulated in accordance with the synchronization signal 34 obtained from the main sentence synchronization signal generation means 30.
The amplitude modulating means 32 keeps the signal on and off while the main text is being transmitted, and cuts it off when the transmission ends. The receiving means 23 of the terminal device 19 that receives the signals sent in this way includes an amplitude modulation demodulation means 38 and a phase modulation demodulation means 39.
and a synchronization signal detection means 4o.

When receiving the preamble data, the amplitude modulation demodulation means 38 demodulates the preamble data 41 in accordance with the timing based on the time limit of the power synchronization signal 42, and at the same time, the phase modulation demodulation means 39
The phase of the carrier wave is detected by the synchronization signal detecting means 4o, and the phase change point is detected by the synchronization signal detection means 4o to obtain the synchronization signal of the main text that is subsequently transmitted.0However, when the carrier wave signal is not sent to the path 4, Since the output of the phase modulation demodulation means 39 is not fixed, the detection signal 43 indicating whether or not a carrier wave is being sent is inputted from the amplitude demodulation means 38, and a synchronization signal is found only when a carrier wave is present. prevents the creation of synchronization signals. The main text data 46 is demodulated by the phase modulation demodulation means 39 in accordance with the synchronization signal 44 obtained by the synchronization signal detection means 40 while receiving the preamble. FIG. 6 is the voltage waveform of the commercial frequency power supply, 16 is the power synchronization signal waveform of the output 36° 42 of the power supply synchronization signal generating means 24.25. 0 Preamble Data 41 is transmitted by amplitude modulation with a time limit based on the power supply synchronization signal 16. and continues with main sentence 45
048 and below are diagrams in which the last bit of the preamble and the main sentence are temporally expanded. 48 is an enlarged version of the power synchronization signal waveform 15. 49 is
3 is a diagram showing a signal waveform superimposed on path 4. FIG.

First, the waveforms of each part when receiving the preamble part will be explained.

The preamble refers to amplitude modulation by transmitting and not transmitting a carrier wave,
The transmitted carrier wave is further phase modulated by the phase modulation means 31 in accordance with the main synchronization signal 34. 060 is the output waveform of the output 43 demodulated by the amplitude modulation demodulation means 38 as amplitude modulation depending on the presence or absence of the carrier wave. When the carrier wave is received in the first half phase of 60 half cycles of the voltage waveform, the data is “
0#, similarly when the carrier wave is received in the latter half of the half cycle'
It is defined and interpreted as 1#. In the example shown in this figure, the output waveform 60 is O during the first half of the power synchronization signal pulse 480 interval.
Since it is N, the 0 amplitude modulation demodulation means 38 which is data Ill Q Jl outputs “0” as preamble demodulation data 41.
Output. 61 is the output waveform of the phase modulation demodulation means 39. In the example shown in this figure, the phase of the output waveform 50 is inverted from 0 to -π to 0 every % of the ON period. The synchronization signal detection means 4o detects the timing of the phase change and continues to output the pulse 62 for each cycle of the phase change. This pulse is for receiving the main text sent later, and the main text is the previous one. In the text, it is promised that one bit will be sent every change period based on the timing at which the phase of the carrier wave changes.When the carrier wave is not sent, that is, the output waveform 60 of the amplitude modulation demodulation means 38 is O
During the FF period, phase information is not sent from the transmitting terminal, so the phase change timing information detected during the ON period is held.

Next, the functions of each part when receiving the main text will be explained. Since the carrier wave is continuously sent while receiving the main text, the output waveform 6o of the amplitude modulation demodulation means 38 remains ON.

The output waveform 51 of the phase modulation demodulation means is detected by the synchronization signal detection means 4.
The main sentence data is read as one break every 62 pulses of 0. For example, when receiving the main text, such as 0 or more where phase -π is defined as "1" and phase 0 as "0", the power supply synchronization signal 48, which causes errors due to distortion of the power supply waveform, is used to separate each bit. Instead, since the synchronization signal extracted from the signal transmitted from the transmitting terminal is used, highly accurate reception is possible without being affected by power waveform distortion. Furthermore, since the delay time for a signal to travel from the transmitting terminal to the receiving terminal is the same for both the preamble and the main text, the error in signal delay time is canceled out.

Next, using FIG. 3, we will describe a state in which a plurality of terminals start transmitting at the same time. ◎63 is the power supply voltage of the commercial frequency. The two terminals 1.2 shown in Figure 4 are now each trying to send data as 64.55.
The data consists of a preamble and a main text, and the preamble is commercial power supply 6
“0-” and “1” depending on whether the carrier wave is sent out in the first half or the second half of the 30 half cycle.
′ is defined. Terminal 2 that received the first half of “0”6e
does not transmit the latter half "1" 67. In other words, the actual transmission by each terminal is as shown in 68.59. Terminal 2, which tried to transmit "001" in the preamble, sends data "001".
When it receives ``66, it stops transmitting, waits for the other terminal 1 to complete its transmission, and then starts transmitting again from the beginning.In the end, the signal actually sent to the signal transmission line is 60.
become that way. Here, the carrier wave in the preamble is modulated by the synchronization signal in the main text, so the receiving terminal detects the synchronization signal from there, but the first two terminals (61.62) are the two terminals (1.2). Since the transmitted signals from the terminals are overlapped and cross-modulated, it is impossible to separate and detect only the synchronization signal of terminal 1. However, the last bit 6 of the preamble
3 is transmitted only by terminal 1, so if you obtain a synchronization signal from this, you can correctly receive the main text 64 transmitted by terminal 1. 0 A different value is always assigned to each terminal. For example, "000", the signals will not overlap with all the bits in the preamble.

With "1oo" and "1oo", the terminal that tries to output "1" from the first bit does not transmit, so there is no bit where the signals overlap, and with "000" and "010", there is no overlapping signal from the second bit. It disappears. In this way, in any combination, there is no overlapping signal at least in the last bit of the preamble, and if the synchronization signal of the main sentence is obtained from the last bit of the preamble, a correct synchronization signal can always be obtained. Although phase modulation has been described in the above embodiments, frequency modulation, amplitude phase modulation, or amplitude frequency modulation may also be used.

Effects of the Invention As described above, the present invention is provided with a plurality of terminals each having a transmitting means and a receiving means connected to a path, and the message outputted by the transmitting means is the main message transmitted following the preamble. Toyo configuration 9, the preamble is a synchronization signal for receiving the main text, and the carrier wave that has been subjected to phase modulation, amplitude phase modulation, frequency modulation, or amplitude frequency modulation is further intermittently subjected to amplitude modulation, and sent out. The main sentence is transmitted in synchronization with the synchronizing signal in the preamble by amplitude phase modulation, frequency modulation, or amplitude frequency modulation, and the receiving means detects the synchronizing signal from the preamble transmitted by the transmitting means to receive the main sentence. This is a transmission control method that allows synchronization signals to be obtained with sufficient time accuracy.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the configuration of a device using the transmission control method of the present invention, FIG. 2 is a conceptual diagram showing an embodiment of the transmission control method of the present invention, and FIG. A diagram explaining the operation when the terminals start transmitting at the same time, FIG. 4 is a diagram showing the connection of the transmission control device, FIG. 6 is a diagram showing the data transmission status, FIG. 6 is a diagram of the structure of the message, FIG. 7 is a diagram illustrating a time shift in a power synchronization signal due to waveform distortion of a commercial power source. 1.2.3...terminal, 4...bus,
5... Voltage waveform of commercial frequency power supply, 16...
...power synchronization signal, 20.21...receiving means, 22.23...transmission means, 31...
Phase modulation means, 32... Amplitude modulation means, 38.
... Amplitude modulation demodulation means, 39 ... Phase modulation demodulation means, 4o ... Synchronization signal detection means O-th
2nd part 3rd figure 4rgI 5th figure 7th diagram'

Claims (2)

[Claims] (1) Equipped with a plurality of terminals having transmitting means and receiving means connected to a path, the message outputted from the transmitting means consists of a preamble and a main text that is transmitted following the preamble, and the preamble is the main text. A carrier wave that has been subjected to phase modulation, amplitude phase modulation, frequency modulation, or amplitude frequency modulation is further intermittently subjected to amplitude modulation with a synchronization signal for receiving. A transmission control method in which the synchronization signal in the preamble is transmitted by amplitude frequency modulation in synchronization with the synchronization signal in the preamble, and the receiving means detects the synchronization signal from the preamble transmitted by the transmitting means and receives the main sentence. (2) The transmission control method according to claim 1, wherein the main sentence is received using a synchronization signal obtained from the last bit of the intermittent amplitude modulation signal of the preamble.