JP6521436B2 - Path branching device and voltage branching circuit - Google Patents

Description

  The present invention relates to a communication system technology, and in particular, a node that performs current data communication using current signals and a node that performs voltage data communication using voltage signals are connected by two wire routes consisting of a two-core cable shared during data communication. Relates to a route branching technique for branching into two.

  Conventionally, in an equipment management system for managing building equipment and industrial equipment, for example, an Ethernet (registered trademark) communication system is used as a high-order network responsible for data communication between various servers and controllers, for example, between the controller and each node A current loop communication system is used as a lower layer network that is responsible for data communication (see, for example, Patent Document 1).

JP 2005-348549 A

  Such a conventional technology is a system for switching the current value, and the communication speed is very slow at about 4800 bps. In particular, along with the intelligentization of the facility management system, it is not possible to cope with the speedup of the lower network. As one of the solutions for speeding up such lower network, there is a method of replacing the current loop communication system with an Ethernet communication system. At this time, it is necessary to change the existing transmission cable for current loop (2 cores) to a LAN cable (4 cores), but in practice, considerable time and cost are generated, and in some cases cable change is difficult in some cases In some cases.

  As a technology for performing digital communication with a two-core cable, there is a PLC (Power Line Communication) method. The PLC method is a technology for realizing various digital communications such as Ethernet communication with a two-core power line, and a method of coexistence of a current loop communication system and an Ethernet communication system using this PLC method is conceivable. .

  FIG. 2 is a configuration example of a communication system using the PLC method. That is, when the C node 11 performing current loop communication with the two-core communication cable 40 and the E node 12 performing Ethernet communication with the communication cable 40 via the PLC modem 22 coexist, the communication cable 40 and the C node 11 The CP filter 31 is connected between them to block the PLC signal from the communication cable 40 to pass the current loop signal, and the PP filter 32 is connected between the communication cable 40 and the PLC modem 22 to connect the communication cable. The current loop signal from 40 is cut off to pass the PLC signal.

On the other hand, when the communication system is actually arranged, the communication cable may be branched halfway in order to efficiently wire according to the arrangement position of the node.
FIG. 3 is an explanatory view showing a branching example of the communication cable. In the case of the communication system of FIG. 2, since the signal form of the current loop communication is a current signal, according to the branch example of FIG. 3, the values of the current signals Im, Ia and Ib in the main path M and the branch example paths A and B. Therefore, even if the communication cable 40 is branched halfway, current loop communication is maintained.

  However, since the signal form of Ethernet communication using the PLC modem 22 is a voltage signal, according to the branch example of FIG. 3, the values of the voltage signals Vm, Va, Vb in the main path M and the branch example paths A and B are Since the voltage signals Vm are not equal to each other and the voltage signal Vm is actually divided into Va and Vb, there is a problem that Ethernet communication can not be performed when the communication cable 40 is branched halfway.

  The present invention is intended to solve such problems. Even when a node performing current data communication using a current signal and a node performing voltage data communication using a voltage signal coexist, the wiring path can be The purpose is to provide a route branching technique that can be branched into two on the way.

  In order to achieve such an object, in the path branching device according to the present invention, a node performing current data communication using a current signal and a node performing voltage data communication using a voltage signal are shared during data communication. A path branching unit for branching a wiring path consisting of a two-core cable into two, wherein the voltage data of the main voltage signal used for the voltage data communication separated from the main path is transmitted via the first branch path A voltage branch circuit that branches into a first branch voltage signal used for communication and a second branch voltage signal used for the voltage data communication via a second branch path, and the current data communication separated from the main path A first branch current signal used for the current data communication via the first branch path, and a second current signal used for the current data communication via the second branch path. As a branch current signal, and a current loop circuit which sequentially loop.

  Further, according to one configuration example of the above-described path branching device according to the present invention, the voltage branching circuit is paired with an impedance conversion transformer connected to the main path via a main capacitor of which primary side is paired. A first transmission line transformer connected to the first branch path via a first capacitor, and a second transmission path connected to the second branch path via a second capacitor having a secondary side as a pair. The primary side of the first and second transmission line transformers are connected in parallel to the secondary side of the impedance transformation transformer.

  Further, according to one configuration example of the above-described path branching device according to the present invention, the current loop circuit connects a first line of the main path and one line of the first branch path; A second coil connecting the other line of the first branch path and one line of the second branch path, the other line of the second branch path, and the other line of the main path And a second coil connecting the

  The voltage branch circuit according to the present invention is a voltage branch circuit that branches a voltage signal used for data communication from the main path to the first and second transmission paths, and the impedance conversion in which the primary side is connected to the main path A transformer, a first transmission line transformer whose secondary side is connected to the first branch path, and a second transmission line transformer whose secondary side is connected to the second branch path; The primary side of the second transmission line transformer is connected in parallel to the secondary side of the impedance conversion transformer.

  In one configuration example of the voltage branch circuit according to the present invention, the impedance conversion transformer is a half of the characteristic impedance of the primary side of the first and second transmission line transformers as the characteristic impedance of the secondary side. Have a characteristic impedance of

  According to the present invention, even when a node performing current data communication using a current signal and a node performing voltage data communication using a voltage signal coexist, the wiring path can be branched into two along the way It becomes. Therefore, by arranging the route branching unit according to the present invention in the middle of the wiring route, the installation position of the node can be selected without being limited to the arrangement position of the wiring route, and the communication system and further the facility management system As a result, it is possible to construct a flexible system with a high degree of freedom.

It is a circuit diagram showing composition of a path branching device concerning the present invention. It is a structural example of the communication system using a PLC system. It is explanatory drawing which shows the example of a branch of a communication cable.

Next, an embodiment of the present invention will be described with reference to the drawings.
[Path branching device]
First, with reference to FIG. 1, the path branching device 1 according to the embodiment of the present invention will be described. FIG. 1 is a circuit diagram showing the configuration of a path branching device according to the present invention.

  The path branching unit 1 has two wiring paths including a two-core cable shared by the node performing current data communication using current signals and the node performing voltage data communication using voltage signals during data communication. It has a branching function. Here, the main path M connected to port Pm is divided into a branch path (first branch path) A connected to port Pa and a branch path (second branch path) B connected to port Pb. The case of branching into two will be described as an example.

  As a communication system to which the route branching device 1 is applied, for example, a node that is used in a facility management system that manages a building facility or an industrial facility and performs current loop communication using current signals by a wiring route composed of a two-core cable And a node that performs Ethernet communication via a PLC modem using voltage signals.

The route branching unit 1 is provided with a voltage branching circuit 2 and a current loop circuit 3 as main circuit units.
Voltage branch circuit 2 divides a main voltage signal Vm used for voltage data communication separated from main path M, a branch voltage signal (first branch voltage signal) Va used for voltage data communication via branch path A, and a branch path It has a function of branching into a branch voltage signal (second branch voltage signal) Vb used for voltage data communication via B.

  Specifically, voltage branch circuit 2 includes an impedance conversion transformer Tm connected to main path M via capacitors (main capacitors) Cm1 and Cm2 having a pair on the primary side, and a capacitor having a pair on the secondary side (first Capacitors) a transmission line transformer (first transmission line transformer) Ta connected to the branch path A via Ca1 and Ca2 and a branch via capacitors (first capacitors) Cb1 and Cb2 whose secondary side forms a pair A transmission line transformer (second transmission line transformer) Tb connected to the path B is provided, and the primary sides of the transmission line transformers Ta and Tb are connected in parallel to the secondary side of the impedance conversion transformer Tm.

The impedance conversion transformer Tm is a general conventional transformer that performs impedance conversion by electromagnetically coupling the primary side and the secondary side, and the windings on the primary side and the secondary side are electrically separated.
On the other hand, the transmission line transformers Ta and Tb are transformers having a configuration in which the primary side and the secondary side are electromagnetically coupled in an alternating current, and the primary side and a secondary side are connected in a direct current. .

  Capacitors Cm1 and Cm2 have a function of separating main voltage signal Vm from main current signal Im from main path M connected to port Pm and inputting it to the primary side of impedance conversion transformer Tm, and the primary side of impedance conversion transformer Tm And a function of superposing the main voltage signal Vm output from the main path M on the main path M.

  The capacitors Ca1 and Ca2 have a function of superposing the branch voltage signal Va output from the secondary side of the transmission line transformer Ta on the branch path A connected to the port Pa, and the branch voltage signal Va from the branch path A is a branch current It has a function to be separated from the signal Ia and to be input to the secondary side of the transmission line transformer Ta.

  Capacitors Cb1 and Cb2 have a function of superposing branch voltage signal Vb output from the secondary side of transmission line transformer Tb on branch path B connected to port Pb, and branch current from branch path B to branch current of branch voltage signal Vb It has a function to be separated from the signal Ib and to be input to the secondary side of the transmission line transformer Tb.

  The current loop circuit 3 divides a main current signal Im used for current data communication separated from the main path M, a branch current signal (first branch current signal) Ia used for current data communication via the branch path A, and a branch A branch current signal (second branch current signal) Ib used for current data communication via the path B has a function of sequentially looping.

  Specifically, current loop circuit 3 includes a coil (first coil) L1 connecting one of lines Lm1 of main path M and one of lines La1 of branch path A, and a path of branch path A A coil (second coil) L2 connecting the other line La2 of the two and the one line Lb1 of the branch path B, and the other of the other line Lb2 of the branch path B and the main path M It is comprised from the coil (3rd coil) L3 which connects track | line Lm2.

[Operation of this embodiment]
Next, with reference to FIG. 1, the operation of the route branching device 1 according to the present embodiment will be described.

[Division operation of voltage signal]
First, the branching operation regarding the voltage signal in the path branching device 1 will be described.
Main voltage signal Vm used for voltage data communication input from main path M is input to path splitter 1 through port Pm, and main current signal for current data communication flowing through main path M by capacitors Cm1 and Cm2. It is separated from Im and input to the voltage branch circuit 2.

After that, the main voltage signal Vm is input to the primary side of the impedance conversion transformer Tm, impedance converted, output from the secondary side, branched into two, and input to the primary sides of the transmission line transformers Ta and Tb respectively. .
At this time, the primary side and the secondary side of the transmission line transformers Ta and Tb have characteristic impedances equal to that of the branch paths A and B, for example, Zo = 120 Ω, in order to impedance match the branch paths A and B. There is.

Similarly, the primary side of the impedance conversion transformer Tm also has a characteristic impedance equal to that of the main path M, for example, Zo = 120Ω, in order to perform impedance matching with the main path M.
On the other hand, the secondary side of the impedance conversion transformer Tm has a characteristic impedance which is 1/2 of the characteristic impedance of the primary side of the transmission line transformers Ta and Tb.

Therefore, in the connection section between the secondary side of the impedance conversion transformer Tm and the primary side of the transmission line transformers Ta and Tb, the characteristic impedance is matched, and the main voltage signal Vm output from the secondary side of the impedance conversion transformer Tm. Decays by 1 / √2.
As a result, from the secondary side of the transmission line transformer Ta, a branch voltage signal Va having an amplitude voltage corresponding to Vm / √2 is output.
Similarly, from the secondary side of the transmission line transformer Tb, a branch voltage signal Vb having an amplitude voltage corresponding to Vm / √2 is output.

Thereafter, the branch voltage signal Va is combined with the branch current signal Ia for current data communication via the branch path A by the capacitors Ca1 and Ca2 and output to the branch path A connected to the port Pa.
Further, the branch voltage signal Va input from the branch path A passes through the signal path in the reverse order to that described above, and is then used as the main voltage signal Vm by the capacitors Cm1 and Cm2 for mains for current data communication via the main path M. The current signal Im is combined with the current signal Im and output to the main path M connected to the port Pm.

On the other hand, branch voltage signal Vb is combined with branch current signal Ib for current data communication via branch path B by capacitors Cb1 and Cb2, and is output to branch path B connected to port Pb.
Further, the branch voltage signal Vb input from the branch path B passes through the signal path in the reverse order to that described above, and is then used as the main voltage signal Vm by the capacitors Cm1 and Cm2 for mains for current data communication via the main path M. The current signal Im is combined with the current signal Im and output to the main path M connected to the port Pm.

[Division operation of current signal]
Next, the branching operation regarding the current signal in the path branching device 1 will be described.
The main current signal Im used for current data communication input from the line Lm1 of the main path M is input to the current loop circuit 3 of the path branching device 1 through the port Pm. Here, after being separated from the main voltage signal Vm for voltage data communication flowing on the main path M by the coil L1, it is synthesized with the branch voltage signal Va for voltage data communication flowing on the branch path A, and is taken as the branch current signal Ia. , And the line La1 of the branch path A connected to the port Pa.

  The branch current signal Ia returned to the line La2 via a node (not shown) connected to the branch path A is input to the current loop circuit 3 of the path branch 1 via the port Pa. Here, after being separated from the branch voltage signal Va of the branch path A by the coil L2, it is combined with the branch voltage signal Vb for voltage data communication flowing through the branch path B and is connected to the port Pb as a branch current signal Ib. It is supplied to the line Lb1 of the branch path B.

  The branch current signal Ib returned to the line Lb2 via a node (not shown) connected to the branch path B is input to the current loop circuit 3 of the path branch 1 via the port Pb. Here, after being separated from the branch voltage signal Vb of the branch path B by the coil L3, the line of the main path M is combined with the main voltage signal Vm of the main path M and connected to the port Pm as the main current signal Im. It is supplied to Lm2.

[Effect of this embodiment]
As described above, according to the present embodiment, the main voltage signal Vm used for voltage data communication separated by the voltage branch circuit 2 from the main path M is a branch voltage signal Va used for voltage data communication via the branch path A; The main current signal Im used for current data communication which is branched to the branch voltage signal Vb used for voltage data communication via the branch path B and the current loop circuit 3 is separated from the main path M is a current via the branch path A The branch current signal Ia used for data communication and the branch current signal Ib used for current data communication via the branch path B are looped in order.

  Further, as a specific configuration of the voltage branch circuit 2, an impedance conversion transformer Tm connected to the main path M via the main capacitors Cm1 and Cm2 having a pair on the primary side and a capacitor Ca1 and Ca2 having a pair on the secondary side Transmission line transformer Ta connected to the branch path A, and a transmission line transformer Tb connected to the branch path B via the capacitors Cb1 and Cb2 on the secondary side, and these transmission line transformers Ta and Tb The primary side is connected in parallel to the secondary side of the impedance conversion transformer Tm.

  Thus, even when a node performing current data communication using a current signal and a node performing voltage data communication using a voltage signal coexist, the wiring path can be branched into two along the way. Therefore, by arranging the route branching unit according to the present invention in the middle of the wiring route, the installation position of the node can be selected without being limited to the arrangement position of the wiring route, and the communication system and further the facility management system As a result, it is possible to construct a flexible system with a high degree of freedom.

  Further, in the voltage branch circuit 2, the impedance conversion transformer Tm has a characteristic impedance which is 1/2 of the characteristic impedance of the primary side of the transmission line transformers Ta and Tb as the characteristic impedance on the secondary side. The characteristic impedance is matched in the connection section between the secondary side of the transformer Tm and the primary side of the transmission line transformers Ta and Tb, and the reflection of the main voltage signal Vm output from the secondary side of the impedance conversion transformer Tm is suppressed be able to.

[Extension of the embodiment]
As mentioned above, although this invention was demonstrated with reference to embodiment, this invention is not limited to the said embodiment. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention. Moreover, about each embodiment, it can combine arbitrarily and can be implemented in the not conflicting range.

  DESCRIPTION OF SYMBOLS 1 ... Path branching device, 2 ... Voltage branch circuit, 3 ... Current loop circuit, Tm ... Impedance conversion transformer, Ta, Tb ... Transmission line transformer, L1, L2, L3 ... Coil, Cm1, Cm2, Ca1, Ca2, Cb1, Cb2 ... capacitor, M ... main path, A, B ... branch path, Lm1, Lm2, La1, La2, Lb1, Lb2 ... line, Pm, Pa, Pb ... port, Vm ... main voltage signal, Va, Vb ... branch voltage Signal, Im: main current signal, Ia, Ib: branch current signal.

Claims (3)

A path brancher for branching a wiring path consisting of a two-core cable shared by a node performing current data communication using current signals and a node performing voltage data communication using voltage signals into two And
A first branch voltage signal using the main voltage signal used for the voltage data communication separated from the main path for the voltage data communication via the first branch path, and the voltage data communication via the second branch path A voltage branch circuit that branches into a second branch voltage signal used for
A main current signal used for the current data communication separated from the main path is a first branch current signal used for the current data communication via the first branch path, and a second current path via the second branch path And a current loop circuit configured to loop sequentially as the second branch current signal used for the current data communication. In the path branching unit according to claim 1,
The voltage branch circuit is connected to the first branch path via an impedance conversion transformer connected to the main path via a primary capacitor forming a pair on the primary side, and a first capacitor forming a pair on the secondary side. A first transmission line transformer, and a second transmission line transformer connected to the second branch path via a second capacitor forming a pair on the secondary side, and these first and second transmissions A path branching unit characterized in that a primary side of a line transformer is connected in parallel to a secondary side of the impedance conversion transformer. In the path branching unit according to claim 1 or 2,
The current loop circuit includes a first coil connecting one line of the main path and one line of the first branch path, the other line of the first branch path, and the second branch. A path comprising a second coil connecting one of the paths of the path, and a second coil connecting the other path of the second branch path and the other path of the main path. Brancher.

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