JPH0241959B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transmitting unit of a signal transmission system such as a power line carrier system, and its purpose is to be able to repeatedly perform transmission until the transmission is performed correctly; In addition, if there is a change in input data while there is a carrier signal from another transmitting unit on the transmission line, there is an input that stores the change in input data and stores it even when there is no carrier signal on the transmission line. An object of the present invention is to provide a transmitting unit for a signal transmission system that can reliably transmit changes in data.

Figure 1 shows the overall circuit of the transmitting unit T, in which the pulsating current wave obtained by double-wave rectification of the commercial power input to the power input terminals Ia and Ib connected to the power line 1 is shaped into a commercial power source. A synchronization generation circuit 1 that outputs a synchronization signal CL corresponding to a half cycle of , a dedicated LSI that generates transmission data based on this synchronization signal CL
A transmission control circuit 2 consisting of a transmission control circuit 2, a carrier signal generation circuit 3 controlled by a signal from a transmission data output terminal S of this transmission control circuit 2, and this carrier signal generation circuit 3.
An oscillation circuit 4 creates a carrier frequency signal RF of the carrier signal FD outputted from the carrier signal FD, a coupling circuit 5 superimposes the carrier signal FD on the power line l, and a stable direct current is obtained from the full-wave rectified pulsating current to power each circuit. a DC stabilized power supply section 6 for separating the signal superimposed on the power line l in a coupling circuit 5, shaping the waveform and outputting the waveform to the reception input terminal SN of the transmission control circuit 2; It is comprised of an input circuit section to be described later, an address setting section 8 consisting of a dip switch, and the like.

The transmission control circuit 2 determines whether or not data is currently being transmitted from another transmitting unit T or an operation confirmation signal from the receiving unit R is being transmitted to the power line L, which is a transmission line, depending on whether there is an input to the receiving input terminal SN. a reception monitoring determination function that determines whether the strobe signal is rising, a strobe signal determination function that determines whether there is a rising edge of the strobe signal at the strobe signal input terminal ST, and an address determination function that determines the address setting contents of the address setting section 8. In addition, the data input terminal i ₀
~i Reads the input data of ₃ , creates address data AD and device control data DT, and generates bit serial transmission data DS for turning on and off the carrier signal generation circuit 3 based on these data signals and synchronization signal CL. or a set of carrier signal FD
When the output ends, a transmission end signal is generated from the output terminal ES, and when the transmission is performed correctly, a signal matching the input data is generated at the data output terminals _O0 to _O3 , which are provided corresponding to the data input terminals _i0 to _i3 , respectively. These operating programs are stored in the dedicated LSI in advance, and the transmission control circuit 2 performs control operations in accordance with the operating programs. As shown in the figure, the input circuit section is provided with an external operation signal input circuit 9 consisting of photo couplers PH ₀ to PH ₃ corresponding to data input terminals i ₀ to i ₃ , respectively, and corresponding to each photo coupler PH ₀ to RH ₃ , The signals of the photo couplers RH ₀ to PH ₃ are latched at the rising edge of the clock and the latched outputs are sent to the data input terminals i ₀ to ^{i 3} of the transmission control circuit 2.
Latch circuits _{10 0} to 10 ₁ are respectively input to _the
Consists of EOR ₁₀ ~ EOR ₁₃ , photocoupler PH ₀
~PH ₃ signal and transmission control circuit 2 data output terminal
O ₀ ~ O ₃ signals and exclusive OR EOR ₁₀ ~
A first comparator circuit 11 compares each gate output with EOR ₁₃ and uses it as the clock of the corresponding latch circuit 10 ₁ to 10 ₃ , and an exclusive OR corresponding to the latch output of each latch circuit 10 ₀ to 10 ₃ . Consists of EOR ₂₀ to _{EOR 23} , data output terminal of transmission control circuit 2
Each output of O ₀ to O ₃ and the latch output of latch circuits 10 ₀ to 10 ₃ are compared by exclusive OR EOR ₂₀ to EOR ₂₃ , respectively, and each gate output is connected to a diode OR circuit consisting of diodes D ₀ to D ₃ . A second comparator circuit 13 connected to the strobe signal input terminal ST of the transmission control circuit 2 via 12 and a second comparison circuit 13 connected to the strobe signal input terminal ST of the transmission control circuit 2, and a second comparison circuit 13 connected to the strobe signal input terminal ST of the transmission control circuit 2, and a It consists of a transistor Tr whose output is grounded.

Next, the operation of the transmitting unit T will be explained. First, in the state shown in FIG. 2A, in which no carrier signal from another unit is transmitted to the power line 1, which is a transmission line, the transmission control circuit 2 is in a transmittable state. Operation switches SW ₀ to _{SW 3} of the external operation signal input circuit 9
For example, when SW ₀ is turned on, a current flows through the light emitting diode LED of the photocoupler PH ₀ to emit light, and the corresponding phototransistor PT is turned on, causing the "H" level signal shown in FIG. 2b to be activated in the corresponding latch circuit 1.
0 ₀ and also to the exclusive OR EOR ₁₀ of the first comparator circuit 11 . At this time, since the data output terminal _O0 of the transmission control circuit 2 is at the "L" level, a gate signal rises at the exclusive OR EOR ₁₀ as shown in FIG. 2c. At the rise of this gate signal, the latch circuit ₁₀₀ latches the input data,
A latch output is generated as shown in FIG. 2d. When the latch output is input to the corresponding exclusive OR EOR ₂₀ of the second comparison circuit 13, the output of the exclusive OR EOR ₂₀ becomes "H" level as shown in FIG. It is input to the strobe signal input terminal ST of the transmission control circuit 2. FIG. 2h shows a strobe signal. When the strobe signal changes from "L" to "H" level, the transmission control circuit 2 enters the transmission operation, and first the data input terminals i ₀ to _{i 3}
reads the data from the latch circuits 10 ₀ to 10 ₃ and changes the signal state of the data input terminal i ₀ to "H" level according to the signal state of the data input terminals i ₀ to i ₃ . Equipment control data according to
At the same time as creating DT, address data AD is created based on the address set in the address setting section 8, and bit serial transmission data DS is formed by adding these data and a start mark.
The carrier signal generation circuit 3 is turned on and off based on the transmission data DS and the synchronization signal CL, and the carrier signal FD consisting of the carrier frequency signal RF of the oscillation circuit 4 is sent out to the power line l via the coupling circuit 5. Figure 3 shows carrier signal FD
This figure shows an example of the configuration of STR in Figure a, where STR is a start signal that transmits a start mark, AD is an address signal that transmits address data, DT is equipment control data that transmits input data, and the bit data of each signal is is transmitted in synchronization with each cycle of the commercial power supply voltage V _AC , and the sub-bits are transmitted in sub-bit data transmission sections SB ₁ to _{SB 4} obtained by dividing each half cycle into four. Here the sub bit data is the third
As shown in Figure b, "1" and "0" are set depending on whether or not there is a carrier frequency signal RF in the transmission sections _SB1 to _SB4 , and the sub-bit configuration of the "start mark" is "0101", and the data " The sub-bit configuration for data "1" is "0111", and the sub-bit configuration for data "0" is "0100".

Now, when the transmitting unit T transmits the carrier signal FD via the power line l, the receiving unit R at the corresponding address connected to the power line l as shown in FIG.
Then, while receiving the carrier signal FD, load control is performed using the device control data DT. On the other hand, on the transmitting unit T side, the operation confirmation signal from the receiving unit R or the transmission carrier signal FD on the transmission side is transmitted.
When it is detected that the data has been correctly transmitted by determining whether the data matches the input data, etc., the transmission control circuit 2 sends a signal matching the input data of each data input terminal i ₀ to _{i 3} to the data output terminal O. It will output from ₀ to _O3 . Here, as mentioned above, “H”
Since the level data input terminal is _i0 , an "H" level signal as _shown in _FIG. becomes the "L" level as shown in FIG. 2g. At the same time, comparison circuit 11
The output of exclusive EOR ₁₀ is “L” as shown in Figure 2c.
level. Next, the operation switch SW ₀ of the external operation signal input circuit 9 is turned off, and the phototransistor
PH ₀ is turned off, and therefore the output of the exclusive OR EOR ₁₀ of the comparator circuit 11 becomes "H" level as shown in FIG _.
The latch output of is inverted to "L" level. Therefore, the output of the exclusive OR EOR ₂₀ of the second comparison circuit 13 becomes "H" level as shown in FIG. 2g. This “H” level causes the strobe signal input terminal ST to
becomes “H” level, and the data input terminal O ₀
When the signal output from the comparator circuit 13 goes to "L" level, the output of the exclusive OR EOR ₂₀ of the comparator circuit 13 goes to "L" level, causing the strobe signal input terminal ST to go "L".
level. Further, when the second transmission is completed, a transmission end signal is output as shown in FIG. 2(f).

Now, while the carrier signal FD is being transmitted to the power line l as shown in Figure 5a, the transmission control circuit 2 is configured not to perform any transmission operation even if there is a change in the input data at the data input terminals _i0 to _i3 . I'm getting used to it, but the 5th
While detecting this transmission state as shown in Figure b, for example, the operation switch of the external operation signal input circuit 9 is activated.
SW ₀ is turned on and the phototransistor of the photocoupler
When an "H" level signal is output from PH ₀ , the output of the exclusive OR EOR ₁₀ of the comparator circuit 11 is inverted from "L" level to "H" level as shown in FIG. 5c.
At the time of rising, the latch output of the latch circuit ₁₀₀ is set to "H" level. When the latch output of the latch circuit ₁₀₀ becomes "H" level, the output of the exclusive EOR ₂₀ of the comparator circuit 13 also becomes "H" level as shown in FIG. 8g, and the strobe signal input terminal ST becomes "H" level.
It is set to "H" level as shown in FIG. At this time, since the carrier signal FD of another transmitting unit T is being transmitted on the power line 1, the transmission control circuit 2 does not transmit the input data. Now, when the transmitting state changes to the non-transmitting state, the transmission control circuit 2 uses the latch output of the latch circuit ₁₀₀ as input data and inputs it to the data input terminal _i0.
The data is then read and transmitted. When this transmission is completed, a transmission end signal is outputted as shown in FIG. 5f, and the instantaneous transistor Tr is turned on. Therefore, as shown in FIG. 5h, the strobe signal input terminal ST momentarily goes to the "L" level and then rises to the "H" level again. Therefore, the strobe signal is input to the transmission control circuit 2, and transmission is performed again. On the other hand, since the "H" level signal is output from _the data output terminal _O0 at the same time as the end of the first transmission as _shown in FIG. It rises to the "H" level, latches the input signal of the latch circuit ₁₀₀ which is already at the "L" level, and inverts the latch output from the "H" level to the "L" level as shown in FIG. 5d. Therefore, the signal from the end of the transmission until the latch output changes to the "L" level is output from the data output terminal _O0 as shown in FIG. 5e. On the other hand, the exclusive OR of the second comparison circuit 13
The output of EOR ₂₀ is that during the "H" level period of the latch circuit ₁₀₀ , the output of the data output terminal _O0 is "L" level, and during the "L" level period of the latch circuit ₁₀₀ , the output of the data output terminal _O0 is "L" level. Since it is at the "H" level, the "H" level is maintained during that period as shown in FIG. 5g. However, as described above, the transmission end signal momentarily turns on the transistor Tr and momentarily brings the strobe signal input terminal ST to the "L" level, so that a trigger for starting transmission can be given to the transmission control circuit 2. Now, when the output of the data output terminal _O0 goes to the "L" level, the outputs of the exclusive ORs _EOR10 and _EOR20 of the comparison circuits 11 and 13 go from the "H" level to the "L" level. Then, the transmission end signal at which the second transmission ends is the fifth one.
The signal is output as shown in FIG. 5F, and the input to the strobe signal input terminal ST becomes "L" level as shown in FIG. 5H. Further, the clock input of the latch circuit ₁₀₀ also becomes "L" level. In this way, if there is a change in input data while the carrier signal FD from another transmitting unit T is superimposed on the power line L, the change in input data can be transmitted at the same time as the non-signal state ends. .

Figures 6 and 7 show time charts of each part when the input data is normally at "H" level and changes to "L" level when operating switches SW ₀ to _{SW 3} are operated. This is the case where the carrier signal FD of another transmitting unit T is not superimposed on the power line l, and FIG. Figure 7 also shows the power line l.
In this case, the carrier signal FD of another transmitting unit T is superimposed on
The waveform of the circuit section corresponding to ~h is shown.

By the way, in the case of the above embodiment, the level of the strobe signal input terminal ST is momentarily forced to the "L" level using the transmission end signal to provide the strobe signal, but due to noise etc., the transmission may not be carried out correctly. If the data output terminals O ₀ to O ₃ do not output, or if the transmission control circuit 2 stops operating, the exclusive OR of the comparison circuit 13 becomes
There is a problem in that the outputs of EOR ₂₀ to EOR ₂₃ remain at the "H" level and retransmission cannot be performed even though the input data and the transmission result are different.

By the way, instead of the transmission end signal, the transmission control circuit 1
Transistor Tr outputs pulses that are constantly output during operation.
Alternatively, as shown in FIG. 8, by providing a counter circuit 14 that counts constantly output pulses and adding the output of the counter circuit 14 to the base of the transistor Tr, the transmission control circuit 2 can be If it is functioning normally, the strobe signal will always be input when there is a difference between the input and the transmission result, and even if it is not done correctly due to noise etc., the transmission control circuit will continue to input the strobe signal until the input and transmission result match. Two strobe signals can be input.

Since the present invention includes the transmission control circuit configured as described above, the latch circuit, the first comparison circuit, the second comparison circuit, and the transistor, if the transmission is not performed correctly, A strobe signal can be given to the transmission control circuit simply by turning on a transistor, and the signal transmission can be repeated until the correct transmission is performed, and if the transmission is not performed correctly due to noise etc. This has the effect of ensuring reliable transmission even before.

If the transmission end signal is used as a pulse to drive the transistor, the change in input data received while the transmission line is in a signal transmission state is stored in a latch circuit, and the input data is input when the transmission line is in a non-signal transmission state. It is possible to correctly transmit signals based on changes in data.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of an embodiment of the present invention, Fig. 2a
- h are time charts for explaining the operation of the same as above, Fig. 3 a - b are diagrams for explaining the structure of the carrier signal as above, Fig. 4 is a schematic configuration diagram of the system used in the above, and 5 a - h are time charts for explaining the operation of the same as above. 6a to 7h are time charts for explaining the operation of other usage examples of the same, and FIG. 8 is a main part circuit diagram of another embodiment of the present invention. 9 is an external operation signal input circuit, 10 ₀ to 10 ₃ are latch circuits,
11 is a first comparison circuit, 13 is a second comparison circuit,
l is the power line, ST is the strobe signal input terminal, i ₀
~ i ₃ is the data input terminal, FD is the carrier signal, Tr is the transistor, ES is the transmission end signal terminal, EOR ₁₀ ~
EOR ₁₃ , EOR ₂₀ to _{EOR 23} are exclusive ORs.

Claims (1)

[Claims] 1. A function to determine whether or not the transmission line is in a signal transmission state, and if the transmission line is in a non-signal transmission state and a strobe signal rises, input data is read from the data input terminal and a signal is generated based on the input data. It has a function of sending out the data onto the transmission line, a function of determining whether the transmission has been performed correctly and generating an output that matches the input data from the data output terminal, and a function of generating a transmission end signal at the end of the transmission. a latch circuit that latches an input data signal from the outside at the rising edge of a clock and outputs the latch output to the data input terminal of the transmission control circuit; A first comparison circuit has an exclusive OR that compares the output of the data output terminal with the latch output of the latch circuit, and uses the gate output of the exclusive OR as the clock of the latch circuit, and an exclusive OR that compares the output of the data output terminal with the latch output of the latch circuit and a second comparator circuit which has an exclusive OR and outputs the output of this exclusive OR to a strobe signal input terminal of a transmission control circuit and is grounded via a transistor, and turns on the transistor with the transmission end signal. A transmitting unit of a signal transmission system characterized by comprising: 2. Claim 1, characterized in that the pulse is constantly output during the operation of the transmission control circuit.
Transmission unit of the signal transmission system described in Section 1. 3. The transmitting unit of the signal transmission system according to claim 1, wherein the pulse is configured as a transmission end signal outputted from a transmission control circuit when transmission is completed.