JP2009130500A - Multi-drop communication adapter, and multi-drop communicating system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a multi-drop communication adapter which can select and set a mode between a mode to carry out impedance matching at a branching point and a mode to carry out the impedance matching of a transmission route and a communication device, according to kinds and locating positions of a master unit and slave units of a communication device. <P>SOLUTION: Ports 10, 11, 12 are ports for transmission route connection, and a port 13 is a port for communication device connection. A hybrid circuit 2 distributes an input signal of a port 14 to ports 15, 16, etc. equally, and respective input signals of the ports 15, 16 are transmitted only to the port 14. A mode switching circuit 6 selects and sets a mode between the mode to connect the port 16 and a port 19, and carry out impedance matching at the branching point, and the mode to connect the port 16 and a port 18, and carry out impedance matching of the transmission route and the communication device, according to the kinds and the locating positions of the master unit and the slave units of the communication device. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a multidrop communication adapter and a multidrop communication system to which the multidrop communication adapter is applied.

  A multi-drop communication system is a 1-to-N communication system in which a parent communication device and a plurality of slave communication devices communicate via a common transmission path. Matching with the same value as the characteristic impedance of the line (for example, Patent Document 1), or a communication device connected to the end of the transmission line is terminated, and each communication connected to the transmission line by the multidrop method The apparatus has an impedance sufficiently larger than the characteristic impedance of the transmission line to prevent signal reflection due to impedance mismatch at each branch point in the transmission line.

JP 2001-223115 A

  In other words, in the conventional multi-drop communication system, the impedance of each communication device connected to the transmission line by the multi-drop method is not sufficiently larger than the characteristic impedance of the transmission line, but the characteristic impedance of the transmission line. When the impedance is considerably low, such as a value close to, specifically, when each communication device arranged at each branch point has a termination resistor, the impedance at each branch point is Matching is not achieved and signal reflection occurs.

  Similarly, when the distance from the branch point to the communication device is so long that it is not negligible compared to the wavelength of the frequency of the signal used by the communication device, impedance matching cannot be achieved at each branch point. Signal reflection occurs.

  The present invention has been made in view of the above, and according to the type and location of the base unit / slave unit of the communication device, impedance matching at the branch point, and the impedance between the transmission line and the communication device It is an object of the present invention to obtain a multi-drop communication adapter capable of selecting and setting a mode for matching.

  In addition, the present invention applies the multidrop communication adapter according to the present invention, and each communication device has a termination, or when the distance from the branch point to the communication device cannot be ignored. However, it is an object of the present invention to provide a multi-drop communication system that can suppress signal reflection by matching impedances at branch points and can minimize signal loss at the end of a transmission line.

  In order to achieve the above-described object, the adapter for multidrop communication according to the present invention includes a first cable, a second port, a third port to which a pair cable as a transmission path is connected, and a communication device via the pair cable. Among the three input / output ports A, B, and C that are connected or directly connected to the transmission / reception unit of the communication device, the input to the input / output port A is input to the input / output ports B and C. And a hybrid circuit for transmitting the input to the input / output port B and the input / output port C only to the input / output port A, and the input / output port among the three input / output ports D, E, and F. The port D is connected to the third port, the input / output port E is connected to the input / output port C, the input / output port F is connected to the fourth port, the input / output port F and the input Output port E Between the first port and the input / output port A, the mode switching circuit realizing the hybrid mode connecting the input / output port F and the single mode connecting the input / output port F and the input / output port D, And a transformer interposed between the second port and the input / output port B and between the fourth port and the input / output port F as necessary for impedance conversion or the like. It is characterized by.

  According to the present invention, the hybrid mode and the single mode can be set in advance by the mode switching circuit. In the multidrop communication system, the hybrid mode is a mode for impedance matching at a branch point, and is set when a communication device arranged at each branch point of the transmission path is a slave unit. The single mode is a mode for impedance matching between the transmission line and the communication device. When the communication device is a parent device and when the communication device arranged at the end of the transmission line is a child device. Is set. In this way, depending on the type and location of whether the communication device is a parent device or a child device, a mode for impedance matching at a branch point and a mode for impedance matching between the transmission line and the communication device are provided. There is an effect that it can be selected and set.

  Exemplary embodiments of a multidrop communication adapter and a multidrop communication system according to the present invention will be explained below in detail with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of a multidrop communication adapter according to Embodiment 1 of the present invention. As shown in FIG. 1, a multidrop communication adapter (hereinafter simply abbreviated as “adapter”) 1 includes a hybrid circuit 2, transformers 3, 4, 5 and a mode switching circuit 6 as circuit elements. ing. And as a connection part with the outside, 4 ports of ports 10, 11, 12, and 13 are provided.

  Of these four ports, ports 10, 11, and 12 are connection portions for pair cables that are transmission paths, and port 13 is a connection portion for transmission / reception portions of the communication apparatus. As a connection relationship between the port 13 and the transmission / reception unit of the communication device, in this embodiment, the port 13 is described as being connected to the transmission / reception unit of the communication device via a pair cable. In this case, the port 13 is directly connected to the transmission / reception unit of the communication device. That is, the ports 10, 11, 12, and 13 correspond to the first, second, third, and fourth ports in claim 1, respectively.

  The hybrid circuit 2 includes three ports 14, 15, and 16 as signal input / output ports that perform 2-wire / 4-wire conversion. Of these three ports, port 14 is connected to port 10 via transformer 3, port 15 is connected to port 11 via transformer 4, and port 16 is connected to port 17 of mode switching circuit 6. ing. The ports 14, 15, and 16 correspond to the input / output ports A, B, and C in claim 1, respectively.

  The mode switching circuit 6 is a circuit that can select and set the hybrid mode and the single mode, and includes three ports 18 and 19 in addition to the port 17 described above as signal input / output ports. . The port 18 is connected to the port 12, and the port 19 is connected to the port 13 through the transformer 5. The ports 17, 18, and 19 correspond to the input / output ports D, E, and F in claim 1, respectively.

  Here, in the hybrid circuit 2, the signal input to the port 14 is equally distributed to the port 15 and the port 16. Since high isolation processing is performed between the port 15 and the port 16, each signal input to the ports 15 and 16 is transmitted only to the port 14.

  Impedance is defined for each of the ports 14, 15 and 16 in the hybrid circuit 2. The transformers 3, 4, 5 are provided as means for performing impedance conversion for matching those impedances with the characteristic impedance of the pair cable connected to the ports 10, 11, 13 or the impedance of the communication device.

  Further, when the hybrid circuit 2 is composed of a single-ended unbalanced circuit, the pair cables or communication devices connected to the ports 10, 11, and 13 perform differential balanced transmission. , 5 are provided as means for performing such a balanced / unbalanced conversion operation.

  In other words, when no impedance conversion is required between the hybrid circuit 2 and the ports 10, 11, 13 or the communication device, or when a balanced / unbalanced conversion operation is not required, the transformers 3, 4, All or part of 5 need not be provided. In short, in this embodiment, it will be described that all of the transformers 3, 4 and 5 exist, but all or part of the transformers 3, 4, and 5 are provided as necessary.

  Next, the hybrid mode and the single mode realized by the adapter 1 configured as described above will be described.

  The hybrid mode is realized by setting the mode switching circuit 6 to block between the port 18 and the port 19 and connect the port 17 and the port 19. In this case, the port 16 of the hybrid circuit 2 is connected to the transformer 5 via the mode switching circuit 6. That is, in the hybrid mode, among the four external connection portions, the ports 10, 11, and 13 are used, and the port 12 is not used.

  The signal path in the hybrid mode will be described. The signal input from the port 10 connected to the transmission line is impedance-converted by the transformer 3 to match the impedance of the port 14 of the hybrid circuit 2 and input to the port 14. The The signal input to the port 14 is equally distributed to the port 15 and the port 16. The signal input to the port 15 is impedance-transformed by the transformer 4 so as to match the characteristic impedance of the transmission line connected to the port 11 and sent to the port 11. The signal input to the port 16 is converted to the transformer 5. The impedance is converted to match the impedance of the communication device connected to the port 13 and sent to the port 13.

  Further, the signal input from the port 11 connected to the transmission line is impedance-converted by the transformer 4 to match the impedance of the port 15 of the hybrid circuit 2 and input to the port 15. A signal input to the port 15 is transmitted only to the port 14. Further, the signal input from the port 13 to which the communication device is connected is impedance-converted by the transformer 5 to match the impedance of the port 16 of the hybrid circuit 2 and input to the port 16. A signal input to the port 16 is transmitted only to the port 14. Signals input to the port 14 from the ports 15 and 16 are respectively converted by the transformer 3 to match the characteristic impedance of the transmission line connected to the port 10 and sent to the port 10.

  As described above, in the adapter 1 set to the hybrid mode, a processing operation is performed so that impedance mismatch does not occur at the connection point (branch point) of the transmission line to which the ports 10 and 11 are connected. That is, since there are two ports 10 and 11 connected to the transmission path, the hybrid mode is set for the slave unit arranged at the branch point of the transmission path. In the hybrid circuit 2, a signal passing loss occurs. Therefore, when the hybrid mode is used, a loss occurs in the input / output signal.

  The single mode is realized by setting the mode switching circuit 6 so that the port 17 and the port 19 are disconnected and the port 18 and the port 19 are connected. In this case, the port 12 and the port 13 are connected via the mode switching circuit 6 and the transformer 5. That is, in the hybrid mode, the hybrid circuit 2 is not used. Of the four external connections, the ports 10 and 11 are not used.

  The signal path in the single mode will be described. The signal input from the port 12 connected to the transmission path is impedance-converted by the transformer 5 to match the impedance of the communication device connected to the port 13 and then to the port 13. Sent out. Further, the signal input from the port 13 to which the communication device is connected is impedance-converted by the transformer 5 so as to match the characteristic impedance of the transmission line connected to the port 12 and sent to the port 12.

  As described above, in the adapter 1 set to the single mode, a processing operation is performed so as not to cause impedance mismatch between the transmission line and the communication device. Since the connection part with the transmission line is one of the ports 12, the single mode is set for the master unit arranged at the end of the transmission line or in the middle, and the slave unit arranged at the end of the transmission line Set for. In this single mode, since the hybrid circuit 2 is not used, no loss occurs in the input / output signals.

  As described above, according to the first embodiment, a mode for impedance matching at a branch point and a transmission line according to a function type or an arrangement location of whether a communication device is a parent device or a child device And a multidrop communication adapter capable of selecting and setting a mode for impedance matching between the communication device and the communication device.

  Hereinafter, as Embodiments 2 and 3, configuration examples of a multi-drop communication system to which the adapter 1 shown in FIG. 1 is applied will be shown. In the multi-drop communication system targeted by the present invention, each communication device has a termination in its transmission / reception unit.

Embodiment 2. FIG.
FIG. 2 is a system diagram showing a configuration of a multi-drop communication system according to Embodiment 2 of the present invention. In the second embodiment, a case is shown in which the master unit is arranged on one end side of the transmission path and each slave unit is arranged up to the other end side of the transmission path.

  In FIG. 1, adapters 10-1, 10-2, 10-3,..., 10- (n-1), 10-n each have the configuration shown in FIG. Among them, the adapter 10-1 is arranged at the leftmost end portion of the transmission line, the adapter 10-n is arranged at the rightmost end portion of the transmission line, and the adapters 10-2, 10-3, ..., 10- (n- 1) is arranged at a branch point on the way.

  Since there is no signal branching at the end of the transmission path, the adapters 10-1 and 10-n arranged at both ends of the transmission path are set to the single mode. Therefore, the port for transmission line connection is only port 12. Since there is a signal branch at a branch point in the middle of the transmission path, the adapters 10-2, 10-3, ..., 10- (n-1) are set to the hybrid mode. Therefore, there are two ports 10 and 11 for connection of transmission lines.

  That is, in the adapter 10-1, the port 12 is connected to the port 10 of the next-stage adapter 10-2 via the pair cable 30-1, and in the adapter 10-n, the port 12 is connected to the pair cable 30-n. To the port 11 of the adapter 10- (n-1) at the preceding stage. And between the adapters 10-2, 10-3,..., 10- (n-1), in terms of the connection form from the left end side, the port 11 of the own device and the port 10 of the counterpart device are paired. The cables 30-2, 30-3, ..., 30- (n-1) are connected.

  In the illustrated example, the communication device 20-1 connected to the port 13 of the adapter 10-1 arranged at the leftmost end of the transmission line is the master unit, and the adapter 10-n arranged at the rightmost end of the transmission line. The communication device 20-1 connected to the port 13 is a slave unit. Then, the communication devices 20-2, 20-3, ..., 20- () connected to the respective ports 13 of the adapters 10-2, 10-3, ..., 10- (n-1) arranged in the transmission path. n-1) is a slave.

  In the above configuration, a signal flow in communication between the parent device communication device 20-1 and the child device communication device 20-3 will be described.

  In FIG. 2, the transmission signal of base unit communication device 20-1 is input to port 13 of single-mode adapter 10-1, and is output from port 12 to pair cable 30-1. The base unit transmission signal on the pair cable 30-1 is input to the port 10 of the adapter 10-2 in the hybrid mode, and is output from the port 11 to the pair cable 30-2. The parent device transmission signal on the pair cable 30-2 is input to the port 10 of the adapter 10-3 in the hybrid mode, and is output from the port 13 to the child device communication device 20-3.

  Conversely, the transmission signal of the slave unit communication device 20-3 is input to the port 13 of the hybrid mode adapter 10-3 and output from the port 10 to the pair cable 30-2. The slave unit transmission signal on the pair cable 30-2 is input to the port 11 of the adapter 10-2 in the hybrid mode and output from the port 10 to the pair cable 30-1. And the subunit | mobile_unit transmission signal on the pair cable 30-1 is input into the port 12 of the adapter 10-1 of a single mode, and is output from the port 13 to the main | base station communication apparatus 20-1.

  In this case, since adapter 10-1 to which base unit communication device 20-1 is connected is set to the single mode, loss of signals transmitted to and received from the transmission path can be reduced. The same applies to the adapter 10-n to which the handset communication device 20-n disposed at the rightmost end of the transmission path is connected. Since the adapter 10-3 to which the slave unit communication device 20-3 in the middle of the transmission path is connected is set to the hybrid mode, the master unit communication device is in a state where there is no signal reflection due to impedance mismatch at the branch point. 20-1 can be communicated.

  As described above, according to the second embodiment, in the multi-drop communication system in which the master unit is arranged on one end side of the transmission line and each slave unit is arranged up to the other end side of the transmission line. Since the adapter shown in FIG. 1 is applied, even if the communication device has a terminating resistor, the adapter at the branch point in the middle of the transmission path can be set to the hybrid mode to match the impedance. Signal reflection due to can be suppressed. In addition, the adapters at both ends can be set to a single mode with little loss, and signal loss can be minimized.

Embodiment 3 FIG.
FIG. 3 is a system diagram showing a configuration of a multi-drop communication system according to Embodiment 3 of the present invention. In the third embodiment, a case is shown in which the parent device is arranged in the middle of the transmission line, and each child device is arranged from both ends of the transmission line to the arrangement position of the parent device. For convenience of explanation, the same reference numerals as in FIG. 2 are used in FIG.

  In FIG. 3, the communication device 20-3 is a parent device. The adapter 10-3 to which this is connected is in a single mode, and a pair cable 30-2 directed to the transmission line left end side and a pair cable 30-3 directed to the transmission line right end side are connected to the port 12 thereof. Also, the communication devices 20-2 and 20-1 connected to the adapters 10-2 and 10-1 up to the leftmost end of the transmission line are each a slave unit, and the adapter 10- (n-1) up to the rightmost end of the transmission line. , 10-n are communication devices 20- (n-1) and 20-n, respectively. The adapters 10-1 and 10-n at both ends of the transmission path are each set to the single mode, and each adapter from here to the adapter 10-3 and the adapter 10-2 are respectively set to the hybrid mode.

  Here, in the hybrid mode adapter, signals are good between the ports 11 and 13 and the port 10, but there is a direction that the signal is difficult to pass between the port 13 and the port 11 because the isolation is large. Therefore, when the adapter 10-3 to which the parent communication device 20-3 is connected is set to the hybrid mode, the pair cable 30-2 is connected to the port 10, and the pair cable 30-3 is connected to the port 11, the parent device communication is performed. Communication between the device 20-3 and the slave device communication devices 20- (n-1) and 20-n arranged on the right end side of the transmission line becomes difficult.

  On the other hand, the adapter 10-3 is set to the single mode, and the port 12 is configured to connect the left end side transmission path and the right end side transmission path in parallel, at the transmission path left end side and the transmission path right end side. If the ports 10 and 11 of the hybrid mode adapter are in a bilaterally symmetric relationship, multidrop communication can be performed without any problem between each slave unit and the master unit in both transmission paths.

  As described above, since the adapter shown in the first embodiment can select and set the hybrid mode and the single mode, a system capable of performing multidrop communication regardless of the position of the master unit in the multidrop transmission path. It becomes possible to build.

Embodiment 4 FIG.
FIG. 4 is a block diagram showing a configuration of a multidrop communication adapter according to Embodiment 4 of the present invention. In the fourth embodiment, a multidrop communication adapter that connects a power line communication device instead of a communication device will be described. In FIG. 4, the same or similar components as those shown in FIG. 1 (Embodiment 1) are denoted by the same reference numerals. Here, the description will be focused on the portion related to the fourth embodiment.

  In the power line communication device, it is necessary to supply commercial power to the transmission / reception unit. Therefore, as shown in FIG. 4, in the multidrop communication adapter 20 according to the fourth embodiment, a port 21 to which a commercial power line is connected is added, and an LPF (low pass) is connected between the port 21 and the port 13. A filter: a low-pass filter) 22 is inserted. In addition, an HPF (high pass filter: high pass filter) 23 is interposed between the transformer 5 and the port 13. And the port 13 is connected to the transmission / reception part of a power line communication apparatus via a power line or directly. The port 21 corresponds to the fifth port in claim 2.

  Next, the operation will be described. In the transmission / reception unit of the power line communication apparatus (not shown) connected to the port 13, commercial power input from the port 21 is supplied from the port 13 via the LPF 22, and is ready for transmission / reception. In this case, since the HPF 23 is interposed between the port 13 and the transformer 5, the commercial power supplied to the transformer 5 via the LPF 22 is blocked by the HPF 23 and is not input to the transformer 5.

  A transmission / reception unit of a power line communication device (not shown) superimposes the transmission signal on the commercial power supply and sends it to the port 13. The HPF 22 takes out the signal component superimposed on the commercial power supply and supplies it to the transformer 5. In the reverse path, the signal output from the mode switching circuit 6 to the transformer 5 is output from the HPF 23 toward the port 13, but since the commercial power is supplied from the LPF 22 toward the port 13, the HPF 23 is connected to the port 13. The signal output toward 13 is superimposed on the commercial power supply and input to the transmission / reception unit of the power line communication device (not shown).

  Here, the LPF 22 blocks transmission of a communication signal at the port 13 to the port 21. That is, it is difficult for a communication signal to be output to the commercial power line connected to the port 21. Further, the LPF 22 makes it difficult for the external noise having the same frequency as the signal used for communication to enter the port 13 side even if it is superimposed on the commercial power supply. That is, the LPF 22 is less susceptible to the transmission line characteristics of commercial power lines and noise.

  As described above, according to the fourth embodiment, the adapter is configured so that the power line communication device can be connected, and the adapter is configured not to be affected by the transmission line characteristics and noise of the commercial power line. In the multi-drop communication system shown in FIG. 3, the adapter according to the fourth embodiment is used instead of the adapters 10-1 to 10-n, and the power line communication device is used instead of the communication devices 20-1 to 20-n. It is possible to obtain the same action and effect.

Embodiment 5 FIG.
In the first embodiment (FIG. 1) and the fourth embodiment (FIG. 4), as a preferred configuration of the adapter, the case of having two modes of a hybrid mode and a single mode has been shown. In this fifth embodiment, As a modification, an adapter having only the hybrid mode will be described. An adapter having only the hybrid mode has a signal loss. Therefore, when applied to a multi-drop communication system, the transmission characteristics are slightly inferior, but the adapter can be similarly applied.

(1) In the first configuration, the mode switching circuit 6 and the port 12 are deleted in the configuration shown in FIGS. 1 and 4, and the port 16 of the hybrid circuit 2 is connected to the port 13 via the transformer 5. This is the configuration. In this configuration, the ports 10, 11, and 13 in FIGS. 1 and 4 correspond to the first, second, and third ports in claims 5 and 6, respectively, and the port 21 in FIG. Corresponds to 4 ports.

  In the multi-drop communication system to which the adapter according to the first configuration is applied, the 4-wire-side ports 15 and 16 of the hybrid circuit 2 are separated from each other with high isolation, and signal exchange between them is impossible. As shown in Item 9, one communication device or one power line communication device that is a parent device is arranged on one end side of a transmission path constituted by a pair cable, and a plurality of communication devices or a plurality that are child devices. The power line communication devices of the stand are each arranged up to the other end side of the transmission path. This corresponds to the configuration shown in FIG.

(2) The second configuration is a configuration shown in FIGS. 5 and 6 in which the mode switching circuit 6 is deleted and the relationship between the ports of the hybrid circuit 2 and the external connection ports is changed. FIG. 5 corresponds to FIG. 1 and is a block diagram showing the configuration (part 1) of the multidrop communication adapter according to the fifth embodiment of the present invention. FIG. 6 corresponds to FIG. 4 and is a block diagram showing the configuration (part 2) of the multidrop communication adapter according to the fifth embodiment of the present invention.

  The communication device adapter 30 shown in FIG. 5 has the configuration shown in FIG. 1 except that the mode switching circuit 6 and the port 12 are deleted and the port 16 of the hybrid circuit 2 is connected to the transformer 5. A configuration in which the ports 15 and 16 are connected to the connection ports 31 and 32 of the transmission path via the transformers 4 and 5, and the port 14 of the hybrid circuit 2 is connected to the connection port 33 of the communication device via the transformer 3 It has become. In this configuration, the ports 31, 32, and 33 correspond to the first, second, and third ports in claim 7, respectively.

  Further, the power line communication device adapter 40 shown in FIG. 6 has the configuration shown in FIG. 4 with the mode switching circuit 6 and the port 12 removed, and the port 16 of the hybrid circuit 2 connected to the transformer 5 and the hybrid. The ports 15 and 16 of the circuit 2 are connected to the connection ports 31 and 32 of the transmission line via the transformers 4 and 5, and the port 14 of the hybrid circuit 2 is the port for connecting the power line communication device via the transformer 3 and the HPF 23. The port 41 to which the commercial electric wire is connected is connected to the port 33 via the LPF 22. In this configuration, the ports 31, 32, 33, and 41 correspond to the first, second, third, and fourth ports in claim 8, respectively.

  5 and 6, a signal input to the port 33 from a communication device or power line communication device (not shown) is equally distributed from the port 14 of the hybrid circuit 2 to the ports 15 and 16. The signal distributed to 15 is sent from the port 31 to one transmission line, and the signal distributed to the port 16 is sent from the port 32 to the other transmission line.

  Since high isolation processing is performed between the port 15 and the port 16, signals input from the ports 31 and 32 to the ports 15 and 16 via the transformers 4 and 5 are transmitted only to the port 14. Communicated. A signal exiting the port 14 is transmitted to a communication device (not shown) or a power line communication device connected to the port 33 via the transformer 3.

  The adapters 30 and 40 are configured so that communication is possible between the parent device and the child devices arranged on one side thereof, or communication between the parent device and the child devices arranged on both sides thereof. Therefore, a multidrop communication system cannot be constructed alone, but can be used in the form of (3) described later.

(3) As a configuration of the multi-drop communication system, in addition to the configuration of (9) in which the adapter of the above-described (1) first configuration is applied, as shown in claim 10, the parent device includes the above (2) It is also possible to adopt a configuration in which the adapter of the second configuration is applied and the adapter of the above (1) first configuration is applied to the slave unit. This corresponds to the configuration shown in FIGS.

  As described above, the adapter for multidrop communication according to the present invention can be used even when each communication device has a termination resistor or when the distance from the branch point to the communication device is not long enough to be ignored. Therefore, it is useful for constructing a multi-drop communication system which can suppress signal reflection by matching impedances at branch points and can minimize signal loss at the end of the transmission path.

It is a block diagram which shows the structure of the adapter for multidrop communication by Embodiment 1 of this invention. It is a system diagram which shows the structure of the multidrop communication system by Embodiment 2 of this invention. It is a system diagram which shows the structure of the multidrop communication system by Embodiment 3 of this invention. It is a block diagram which shows the structure of the adapter for multidrop communication by Embodiment 4 of this invention. It is a block diagram which shows the structure (the 1) of the adapter for multidrop communication by Embodiment 5 of this invention. It is a block diagram which shows the structure (the 2) of the adapter for multidrop communication by Embodiment 5 of this invention.

Explanation of symbols

1,20 Multidrop communication adapter (adapter)
2 Hybrid circuit 3, 4, 5 Transformer 6 Mode switching circuit 10, 11, 12 Port for transmission line connection 13 Port for connecting communication device / power line communication device 21 Port for connecting commercial power line 22 LPF
23 HPF
30, 40 Multi-drop communication adapter (adapter)
31, 32 Transmission path connection port 33 Communication device / power line communication device connection port 41 Commercial power supply line connection port

Claims (10)

A first port, a second port, a third port to which a pair cable as a transmission path is connected, and a fourth port to which the communication device is connected via a pair cable or directly connected to the transmission / reception unit of the communication device; ,
Of the three input / output ports A, B, and C, the input to the input / output port A is distributed and transmitted to the input / output ports B and C. A hybrid circuit that transmits only to the input / output port A;
Of the three input / output ports D, E, and F, the input / output port D is connected to the third port, the input / output port E is connected to the input / output port C, and the input / output port F is connected to the input / output port F. Mode switching connected to a fourth port to realize a hybrid mode in which the input / output port F and the input / output port E are connected and a single mode in which the input / output port F and the input / output port D are connected Circuit,
All or one between the first port and the input / output port A, between the second port and the input / output port B, and between the fourth port and the input / output port F. Transformer inserted into the part as necessary for impedance conversion, etc.,
A multi-drop communication adapter characterized by comprising: First, second and third ports to which a pair cable as a transmission path is connected, a fourth port to which a power line communication device is connected via a power line or directly connected to a transmission / reception unit of the power line communication device, And a fifth port to which a commercial power supply is connected;
Of the three input / output ports A, B, and C, the input to the input / output port A is distributed and transmitted to the input / output ports B and C. A hybrid circuit that transmits only to the input / output port A;
Of the three input / output ports D, E, and F, the input / output port D is connected to the third port, the input / output port E is connected to the input / output port C, and the input / output port F is connected to the input / output port F. A mode connected to a fourth port and realizing a hybrid mode in which the input / output port F and the input / output port E are connected and a single mode in which the input / output port F and the input / output port D are connected A switching circuit;
A low pass filter interposed between the fifth port and the fourth port;
A high-pass filter having one end connected to the fourth port;
Between the first port and the input / output port A, between the second port and the input / output port B, and between the other end of the high-pass filter and the input / output port F. A transformer that is inserted as necessary, such as impedance conversion, in whole or in part,
A multi-drop communication adapter characterized by comprising: One transmission device or one power line communication device which is a master unit and a plurality of communication devices or a plurality of power line communication devices which are slave units are provided on a transmission path constituted by a pair cable. Or a multi-drop communication system connected via the multi-drop communication adapter according to 2,
When the master unit is arranged on one end side of the transmission path and each slave unit is arranged up to the other end side of the transmission path, the adapters for multidrop communication at the both end positions of the transmission path are respectively The multi-drop communication adapter that is set to single mode and located at each branch point in the middle is set to the hybrid mode,
A multi-drop communication system. One transmission device or one power line communication device as a master unit and a plurality of communication devices or a plurality of power line communication devices as slave units are respectively connected to a transmission path constituted by a pair cable. A multi-drop communication system connected via the multi-drop communication adapter according to 1 or 2,
When the master unit is arranged in the middle of the transmission line and each slave unit is arranged from both ends of the transmission line to the arrangement position of the master unit, the multi-drop communication at the both end positions of the transmission line The adapter and the multi-drop communication adapter for the parent device are each set to the single mode, and the multi-drop communication adapter for each other child device is set to the hybrid mode, respectively.
A multi-drop communication system. First and second ports to which a pair cable as a transmission path is connected, and a third port to which a communication device is connected via a pair cable or directly connected to a transmission / reception unit of the communication device;
Of the three input / output ports A, B, and C, the input to the input / output port A is distributed and transmitted to the input / output ports B and C. A hybrid circuit that transmits only to the input / output port A;
All or one between the first port and the input / output port A, between the second port and the input / output port B, and between the third port and the input / output port C. Transformer inserted into the part as necessary for impedance conversion, etc.,
A multi-drop communication adapter characterized by comprising: First and second ports to which a pair cable as a transmission path is connected, a third port to which a power line communication device is connected via a power line or directly connected to a transmission / reception unit of the power line communication device, and a commercial power source A fourth port to which the line is connected;
Of the three input / output ports A, B, and C, the input to the input / output port A is distributed and transmitted to the input / output ports B and C. A hybrid circuit that transmits only to the input / output port A;
A low-pass filter interposed between the fourth port and the third port;
A high-pass filter having one end connected to the third port;
Between the first port and the input / output port A, between the second port and the input / output port B, and between the other end of the high-pass filter and the input / output port C. A transformer that is inserted as necessary, such as impedance conversion, in whole or in part,
A multi-drop communication adapter characterized by comprising: First and second ports to which a pair cable as a transmission path is connected, and a third port to which a communication device is connected via a pair cable or directly connected to a transmission / reception unit of the communication device;
Of the three input / output ports A, B, and C, the input to the input / output port A is distributed and transmitted to the input / output ports B and C. A hybrid circuit that transmits only to the input / output port A;
All or one between the first port and the input / output port B, between the second port and the input / output port C, and between the third port and the input / output port A. Transformer inserted into the part as necessary for impedance conversion, etc.,
A multi-drop communication adapter characterized by comprising: First and second ports to which a pair cable as a transmission path is connected, a third port to which a power line communication device is connected via a power line or directly connected to a transmission / reception unit of the power line communication device, and a commercial power source A fourth port to which the line is connected;
Of the three input / output ports A, B, and C, the input to the input / output port A is distributed and transmitted to the input / output ports B and C. A hybrid circuit that transmits only to the input / output port A;
A low-pass filter interposed between the fourth port and the third port;
A high-pass filter having one end connected to the third port;
Between the first port and the input / output port B, between the second port and the input / output port C, and between the other end of the high-pass filter and the input / output port A. A transformer that is inserted as necessary, such as impedance conversion, in whole or in part,
A multi-drop communication adapter characterized by comprising: One communication device or one power line communication device that is a parent device is arranged on one end side of a transmission path constituted by a pair cable, and a plurality of communication devices or a plurality of power line communication devices that are slave devices are A multi-drop communication system arranged up to the other end of the transmission line,
The multi-drop communication system, wherein the master unit and each slave unit are connected to the transmission path via the multi-drop communication adapter according to claim 5 or 6, respectively. One communication device or one power line communication device which is a parent device is arranged in the middle of a transmission path constituted by a pair cable, and a plurality of communication devices or a plurality of power line communication devices which are slave devices are A multi-drop communication system that is arranged from both ends of a transmission path to the arrangement position of the master unit,
The base unit is connected to the transmission line via the multidrop communication adapter according to claim 7 or 8,
Each said subunit | mobile_unit is connected to the said transmission line via the adapter for multidrop communication of Claim 5 or 6, respectively. The multidrop communication system characterized by the above-mentioned.

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