JPH0628353B2 - Transport data transmission / reception method using distribution line - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a data transmission / reception system using a distribution line as a carrier transmission line.

(Problems of Prior Art) When using a distribution line as a carrier transmission line for transmitting and receiving a control signal, for example, there are the following problems.

(B) Depending on the location, there is a frequency band (for example, 5 to 10 kHz) including a frequency at which the line loss becomes infinite, and there is a possibility that reception may be impossible if that frequency band is used.

(B) Strong noise may enter the specific frequency, and the reception rate (ratio of normal received data to transmitted data) decreases.

However, conventionally known distribution line conveying techniques cannot overcome these problems. Therefore, an object of the present invention is to provide a carrier data transmission / reception system that solves these problems.

(Means and Actions for Solving Problems) A carrier data transmission / reception system using a distribution line of the present invention is composed of a synchronization signal and a data signal from the transmission side, as an example thereof is shown in FIG. F format data signal
The S signal modulates two different frequencies at the same time, converts it to a transmission frequency, and transmits it to the distribution line. At the receiving side, either or both of the received two data signals are subjected to double transmission verification and parity check. The above-mentioned object is achieved by selecting from the logic section such that if the detected output after detection is normal data that is correct, these normal data are output, and if they are both normal data, they are not output. Less than,
The present invention will be specifically described with reference to the illustrated embodiments.

(Embodiment) FIG. 1 is a diagram showing an example of a transmission format used in the present invention. In the present invention, for example, a well-known 1: N polling format that allows individual calling is used as a transmission signal. This format consists of a sync signal and a data signal. The sync signal is a bit sync signal (22 bits 1010 …… 1) used to detect the arrival of the signal.
0) and a frame synchronization signal (22 bits 100 ... 01) used to detect the arrangement of address and information signals, and the data signal includes address and information (control or display) signals and these signals. Contains a signal used to check whether an error has occurred. Therefore, if such a format is used, error detection, 1-bit correction, 2-transmission matching and parity check by the CRC method can be performed.

FIG. 2 is a block diagram showing an example of a carrier data transmitting / receiving apparatus used in the present invention, and FIG. 3 is an explanatory diagram showing a frequency conversion method according to the present invention.

The carrier data transmitting / receiving apparatus according to the present invention is divided into a logic A and a carrier section B as shown in FIG. In logic part A,
(1) is a data processing device, (2) is a parallel-serial conversion circuit, and (11) is a serial-parallel conversion circuit. In carrier section B, (3) is a transmission circuit, (4) is a modulation circuit, (5) is a transmission amplifier, (6) a coupling filter, (7) input / output terminals, (8) reception amplifier, and (9) is demodulation. vessel,
(10) is a receiving circuit. A microcomputer can be used for the logic unit A.

The transmission signal generated by the data processing device (1) includes an address (destination) signal, which is converted into a transmission data string by the parallel-serial conversion circuit (2) and is FSK-converted by the data signal in the transmission circuit (3) to generate a frequency. It is converted into a shift (FS) signal. The FS signal has a frequency f as shown in FIG.
_{It is} a modulated wave (for example, 4.06 and 3.86 KHz) centered on ₀ (for example, 3.96 kHz) and shifted by a constant frequency (for example, ± 100 Hz) according to a "1" or "0" signal. This FS signal is frequency-converted by two different frequencies in the modulation circuit (4). For example, SSB is performed with the FS signal. That is, as shown in FIG. 3, the low frequency f ₁ in the modulator (4 _1), the modulator due to the high frequency f ₂ in (4 _2), low group transmission frequency respectively centered on frequencies F ₁ And a high group transmission frequency centered on frequency F ₂ . The transmission frequencies of these two high and low groups are
It is sent to the distribution line via the transmission amplifier (5), the coupling filter (6) and the input / output terminal (7).

A transmission / reception device having the same configuration as the transmission data transmission / reception device of FIG. 2 or a reception device having only a reception system is connected to this distribution line, and this reception device receives the transmission frequencies of the two transmitted groups. Input / output terminal (7) and receiving amplifier (8)
The two groups of frequencies received via the are demodulated at the same frequency as the transmission in the demodulation circuit (9). That is, the demodulator (9 ₁ ) demodulates into the FS signal with the frequency f ₁ and the demodulator (9 ₂ ) into the frequency f ₂ respectively. The two demodulated FS signals are received by the receiving circuits (10 ₁ ), (1
0 ₂ ) is converted into a received data string. The two received data strings are converted into parallel received data by serial-parallel conversion circuits (11 ₁ ) and (11 ₂ ), respectively, and the data processing device
Sent to (1).

In the data processing device (1), the two reception data obtained from the frequencies of the two groups captured by the transport section B are separated by C respectively.
Error detection by RC, 1-bit correction, double-transmission matching and parity check are performed. Judge whether this detection result is correct or not.
And However, error detection and correction may be omitted. Based on the result, the received data is selected and adopted according to Table 1.

In this table, the first case is when both the high and low groups pass each check, and in this case, the data processing device (1) outputs the first-come-first-served basis, outputs the low group with priority, or outputs the high group. It is determined in advance whether to output with priority, and the output is performed according to that. In the second case, the low group passes and the high group fails. In this case, the low group is naturally selected and adopted. In the third case, the low group fails and the high group passes. In this case, the high group is selectively adopted. In the fourth case, both groups are unsuccessful, and no output is given in this case.

By doing so, even when using a distribution line having a frequency at which the line loss becomes infinite or a distribution line having strong noise at a specific frequency, the two frequencies f ₁ and f ₂ are selected at appropriate intervals. If this is done, the situation in which both the high and low groups cannot receive will be avoided, and a reception rate close to 100% can be obtained. Table 2 is a table showing an example of combinations of the center frequencies (F ₁ and F _{2 in} FIG. 3) of the low group and the high group that can be used in the frequency band of 5 to 10 kHz.

Both group frequencies in each set in this table are 2400
It's about Hz apart. With such a combination,
As many transmission lines as there are combinations are obtained.

FIG. 4 is a block diagram showing an application example of the present invention. In this figure, the left side of the one-dot chain line is the substation, the right side is the distribution line, (12) is the parent device installed in the substation, (13) is the three-phase type distribution line (14), for example, the installation of switches. The child device connected to the location is shown. Both the parent device (12) and the child device (13) may be transmission / reception devices having the same configuration as shown in FIG. When it is necessary to control a specific switch, the parent device (12) frequency-converts as described above and sends a two-wave switch control signal to the distribution line (14). This switch control signal includes switch number (address) information, and the child device (13) checks whether the destination of the received control signal is its own and then selects and adopts the received signal as described above. , Control its own switch. In the case of a large distribution line network including a plurality of substations, different combinations of frequencies shown in Table 2 are assigned to each substation. In the past, workers had to go to the site one by one when it was necessary to turn off scattered switches at various places in the distribution line due to construction work, etc. Remarkably improved.

Although it was mentioned earlier that the parent device (12) suddenly sends a switch control signal, in order to ensure accuracy, first call the desired child device (13) and wait for the response from the child device. The slave device sends a control signal, and the child device notifies the parent device of this by turning off the switch.

Further, when used only for one-way transmission, one may be only the transmitting device and the other may be only the receiving device.

(Effects of the Invention) As described above, according to the present invention, in a carrier data transmission / reception device using a distribution line, there is a frequency at which the line loss becomes infinite or a strong noise occurs at a specific frequency in the distribution line. Even if it does, there is an effect that a reception rate close to 100% can be obtained. Therefore, it becomes possible to accurately remotely control devices such as switches connected to various parts of the distribution line at a substation or the like, and work efficiency can be significantly improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a transmission format used in the present invention, FIG. 2 is a block diagram showing an example of a carrier data transmitting / receiving apparatus that can be used in the present invention, and FIG. 3 is an explanation showing a frequency conversion method according to the present invention. 4 and 5 are block diagrams showing an application example of the present invention.

Front page continuation (71) Applicant 999999999 Oi Electric Co., Ltd. 3-3-16 Kikuna, Kohoku-ku, Yokohama-shi, Kanagawa (71) Applicant 999999999 Fuji Denso Co., Ltd. 237, Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa (72) Invention Shiba Kubota 1-1-3 Uchisaiwaicho, Chiyoda-ku, Tokyo Tokyo Electric Power Co., Inc. (72) Masahiro Noda 1-1-3 Uchisaiwaicho, Chiyoda-ku, Tokyo Tokyo Electric Power Co., Ltd. (72) Inventor Shigeru Haga Narita, Kanagawa Prefecture, Yokohama City, Kohoku Ward, 7-3-16, Kikuna Oi Electric Co., Ltd. (72) Inventor, Hiroshi Ishida 515 Kamiganaka, Numazu City, Shizuoka Prefecture (72) Inventor, Akira Ishida, Nishibiwajima-cho, Nishikasugai-gun, Aichi Prefecture 3 of Yoshinocho (72) Inventor Makoto Sakai 237 Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa Fuji Denso Co., Ltd. (56) References JP-A-55-156442 (JP, A) JP-A-54-161815 (JP) , A)

Claims (1)

[Claims] 1. A FS signal obtained according to a data signal of a format consisting of a synchronization signal and a data signal from a transmitting side, simultaneously modulates two different frequencies, converts into a transmission frequency and transmits to a distribution line, and receives. On the side, if the received two data signals are normal data such that the detection output after the detection of the double-transmission collation and the parity check is correct, either of these two data signals, these normal data are output and both must be normal data. A carrier data transmission / reception method using a distribution line, which is characterized in that it is configured to be selected by the logic unit so that it will not be output.