CN207408939U - Bus impedance coalignment, node device and bus system - Google Patents
Bus impedance coalignment, node device and bus system Download PDFInfo
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- CN207408939U CN207408939U CN201721166312.5U CN201721166312U CN207408939U CN 207408939 U CN207408939 U CN 207408939U CN 201721166312 U CN201721166312 U CN 201721166312U CN 207408939 U CN207408939 U CN 207408939U
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Abstract
The utility model provides a kind of bus impedance coalignment, node device and bus system, is related to bussing technique field.Bus impedance coalignment includes switch module and current detection module.Switch module is connected between the build-out resistor and bus.Current detection module be connected to the node device output port and the switch module between connection.It can realize the Auto-matching of the matching impedance to bus system interior joint equipment, without manually determining whether node device is endpoint node, when node device is to access the endpoint node of bus, switch module can control build-out resistor to be linked into bus.When node device is not endpoint node, build-out resistor will not be linked into bus.So that the configuration of matching impedance is faster accurate in bus, manual operation is reduced, ensures the correct matching of bus widening impedance.Intermediate node damage is avoided to cause the situation without matching impedance in bus.
Description
Technical field
The utility model is related to bussing technique field, in particular to a kind of bus impedance coalignment, node device
And bus system.
Background technology
Some common buses design when, in order to ensure the reliability of bus data transfer, it is necessary to consider due to
Bus impedance mismatches the situation for causing signal reflex.In communication process, impedance discontinuity and impedance mismatch can cause letter
Number reflection.Impedance discontinuity refers to that signal suddenly encounters cable resistance very little even without signal is here in line end
Reflection will be caused.The method of this reflection is eliminated, it is necessary to similary with the characteristic impedance of cable in the end of cable bridging one
The terminal resistance of size, the impedance for making cable are continuous.Due to transmission of the signal on cable be it is two-way, communication electricity
The other end of cable can bridge an an equal amount of terminal resistance.
Cause another of signal reflex the reason is that impedance mismatch between data collector and transmission cable.It is this
Reflection caused by reason, when being mainly manifested in communication line and being in idle mode, whole network data corruption.In order to improve network
The topological ability of node, CAN bus both ends need to access the terminal resistance of specific resistance value, it plays very matching bus impedance
Important role if ignoring this resistance, can make the anti-interference of digital communication and reliability substantially reduce or even can not lead to
Letter.During existing progress impedance matching, the position of manually definite impedance matching is needed mostly, easily because maloperation
The matched position of mistake is selected, the impedance matching performance of bus is caused to be deteriorated.
Utility model content
In view of this, the utility model provides a kind of bus impedance coalignment, node device and bus system, can be with
It solves the above problems.
The technical scheme that the utility model is provided is as follows：
A kind of bus impedance coalignment, for carrying out impedance matching to bus system, the bus system includes serial
Multiple node devices of connection, each node device include an impedance-matching device and for accessing the matching of bus electricity
Resistance, the bus impedance coalignment include：
The switch module being connected between the build-out resistor and bus；And
Be connected to the node device output port and the switch module between current detection module, the electric current
Detection module controls the switch module to turn on according to the output current of the output port, makes described in the build-out resistor access
Bus or the control switch module shut-off, make the build-out resistor not access the bus.
Optionally, the current detection module include detection resistance and control chip, described detection resistance one end with it is described
Output port connects, other end ground connection, and the control chip is connected with the detection resistance, to detect the defeated of the output port
Go out electric current；Wherein：
When the control chip detects that the detection resistance both ends do not have pressure drop, the output of the node device is determined
Port does not have electric current, sends first control signal to the switch module, the switch module is controlled to turn on, makes the matching electricity
Resistance accesses the bus；
When the control chip detects that there is pressure drop at the detection resistance both ends, the output terminal of the node device is determined
Mouth has electric current, sends second control signal to the switch module, the switch module is controlled to turn off, makes the build-out resistor not
Access the bus.
Optionally, the current detection module includes current sense amplifier and control chip, the current detecting amplification
Device is connected with the output port, and for detecting whether the output port has electric current, the control chip is examined with the electric current
Amplifier connects, wherein：
The control chip sends first when the current sense amplifier detects that the output port does not have electric current
Control signal gives the switch module, and the switch module is controlled to turn on, and the build-out resistor is made to access the bus；
The control chip sends the second control when the current sense amplifier detects that the output port has electric current
Signal processed gives the switch module, and the switch module is controlled to turn off, the build-out resistor is made not access the bus.
Optionally, the switch module is triode, transistor, field-effect tube or relay switch.
Optionally, the switch module be triode, the triode include base stage, collector and emitter-base bandgap grading, the base stage with
The current detection module connection, the grounded collector, the emitter-base bandgap grading are connected with the build-out resistor, wherein：
When the current detection module detects that the output port does not have electric current, output first control signal is described in
Base stage controls triode ON, and the build-out resistor is accessed the bus；
When the current detection module detects that the output port has electric current output, output second control signal to institute
Base stage is stated, control triode shut-off makes the build-out resistor not access the bus.
Optionally, the model MAX44284 current sense amplifiers of the current sense amplifier or LTC6102 electric currents
Detect amplifier.
Optionally, which further includes：
It is connected with the current detection module, for whether there is the indicative instruction mould of electric current to the output port
Block.
Optionally, the indicating module is light emitting diode.
The utility model additionally provides a kind of node device, and applied to bus system, the bus system includes series connection and connects
The multiple node devices connect, each node device include above-mentioned impedance-matching device and the matching impedance for accessing bus.
The utility model additionally provides a kind of bus system, the above-mentioned node device being connected in series including at least two.
Impedance-matching device provided by the embodiments of the present application can realize the matching impedance to bus system interior joint equipment
Auto-matching, without manually determine node device whether be endpoint node, node device access bus endpoint node when,
Switch module can control build-out resistor to be linked into bus.When node device is not endpoint node, build-out resistor will not be connect
Enter into bus.So that the configuration of matching impedance is faster accurate in bus, manual operation is reduced, ensures bus widening impedance
Correct matching.Intermediate node damage is avoided to cause the situation without matching impedance in bus.
For the above-mentioned purpose of the utility model, feature and advantage is enable to be clearer and more comprehensible, preferred embodiment cited below particularly, and
Attached drawing appended by cooperation, is described in detail below.
Description of the drawings
It, below will be to required use in embodiment in order to illustrate more clearly of the technical solution of the utility model embodiment
Attached drawing be briefly described, it should be understood that the following drawings illustrates only some embodiments of the utility model, therefore should not be by
Regard the restriction to scope as, for those of ordinary skill in the art, without creative efforts, may be used also
To obtain other relevant attached drawings according to these attached drawings.
Fig. 1 is that a kind of bus impedance coalignment that the utility model embodiment provides applies signal in bus system
Figure.
Fig. 2 is a kind of schematic diagram for bus impedance coalignment that the utility model embodiment provides.
Fig. 3 is the schematic diagram for another bus impedance coalignment that the utility model embodiment provides.
Fig. 4 is a kind of schematic diagram for node device that the utility model embodiment provides.
Fig. 5 is a kind of schematic diagram for bus system that the utility model embodiment provides.
Icon：100- bus impedance coalignments；101- switch modules；102- current detection modules；1021- detection electricity
Resistance；1022- controls chip；1023- current sense amplifiers；1024- indicating modules；200- node devices；201- build-out resistors；
202- input ports；203- output ports.
Specific embodiment
Below in conjunction with attached drawing in the utility model embodiment, the technical scheme in the embodiment of the utility model is carried out clear
Chu is fully described by, it is clear that the described embodiments are only a part of the embodiments of the utility model rather than whole realities
Apply example.The component of the utility model embodiment being usually described and illustrated herein in the accompanying drawings can be come with a variety of configurations
Arrangement and design.Therefore, the detailed description of the embodiment of the utility model provided in the accompanying drawings is not intended to limit below
Claimed the scope of the utility model, but it is merely representative of the selected embodiment of the utility model.Based on the utility model
Embodiment, those skilled in the art's all other embodiments obtained on the premise of creative work is not made, all
Belong to the scope of the utility model protection.
It should be noted that：Similar label and letter represents similar terms in following attached drawing, therefore, once a certain Xiang Yi
It is defined, then it further need not be defined and explained in subsequent attached drawing in a attached drawing.It is meanwhile new in this practicality
In the description of type, term " first ", " second " etc. are only used for distinguishing description, and it is not intended that indicating or implying relatively important
Property.
The utility model embodiment provides a kind of bus impedance coalignment 100, as shown in Figure 1, for total linear system
System carries out impedance matching, and the bus system includes multiple node devices 200 of serial connection.Multiple node devices 200 can be with
By connecting with power supply unit, the power supply to each node device 200 is realized.In detail, in bus system, each node is set
Standby 200 can include input port (IN) 202 and output port (OUT) 203.The input port 202 of each node device 200 with
Power supply unit or the output port of adjacent node equipment 200 203 connect, meanwhile, the output port 203 of the node device 200 with
The input port 202 of another adjacent node device 200 connects.It is understood that the last one node in bus system
The output port 203 of equipment 200 can keep idle.The mode being connected in series in this way is realized to every in bus system
The series-fed of a node device 200.Each node device 200 includes an impedance-matching device and for accessing bus
Build-out resistor 201.The impedance-matching device includes switch module 101 and current detection module 102.
Switch module 101 is connected between the build-out resistor 201 and bus.Bus in bus system can include two
The communications cable, the both ends of the build-out resistor 201 of each node device 200 are connected respectively with one in two communications cables.
Switch module 101 can realize that build-out resistor 201 accesses or do not access bus by the control of switch.
Current detection module 102 is connected to the output port 203 of the node device 200 and the switch module 101
Between.The current detection module 102 controls the switch module 101 to turn on according to the output current of the output port 203, makes
The build-out resistor 201 accesses the bus or the control switch module 101 turns off, and the build-out resistor 201 is made not access
The bus.Detailed, current detection module 102 is not when the output port 203 for detecting node device 200 has electric current, table
The bright node device 200 is the end-equipment in bus system, and the end-equipment needs to access build-out resistor in the bus at this time
201,102 controllable switch module 101 of current detection module turns on so that build-out resistor 201 is linked into bus.
In bus system, since multiple node devices 200 of access bus are connected in series with power supply unit, if
The output port 203 of a certain node device 200 is connected to another node device 200, and it is not bus to show previous node equipment 200
End-equipment in system, previous node equipment 200 need not access build-out resistor 201 in the bus.And if a certain node
The output port 203 of equipment 200 does not connect other node devices 200, and it is exactly in bus system to show the node device 200
End-equipment, it is necessary to access build-out resistor 201 in the bus.Node device 200 is not when being end-equipment, output port
203 due to being connected with miscellaneous equipment as load, and output port 203 has electric current.Therefore, it is total in node device 200
In linear system system when connecting the last one node, 203 non-loaded connection of output port, the node device 200 in end it is defeated
Exit port 203 does not just have electric current.Current detection module 102 determines the node by the way that whether detection output mouth 203 has electric current
Whether equipment 200 is end-equipment, so as to control 101 on or off of switch module so that build-out resistor 201 access or
It is not linked into bus.
Detailed, as shown in Fig. 2, the current detection module 102 includes detection resistance 1021 and control chip 1022, institute
It states 1021 one end of detection resistance to be connected with the output port 203, other end ground connection, the control chip 1022 and the detection
Resistance 1021 connects, to detect the output current of the output port 203.Current detection module 102 is by detecting detection electricity
Hinder whether 1021 both ends have pressure drop to determine whether output port 203 has electric current.When the output port of a certain node device 200
203 when being connected to another node device 200, and the output port 203 of previous node equipment 200 just has output current.It can manage
Solution, when the output port 203 of a certain node device 200 is without connecting another node device 200, previous node equipment
200 output port 203 does not just have output current.
When the control chip 1022 detects that 1021 both ends of detection resistance do not have pressure drop, determine that the node is set
Standby 200 output port 203 is turned on without electric current, transmission first control signal to switch module 101, control switch module 101,
The build-out resistor 201 is made to access bus.The node device 200 is the most end end equipment in bus system at this time, passes through access
Build-out resistor 201 can eliminate the signal reflex in bus, improve the anti-interference of bus communication and the reliability of communication.
When the control chip 1022 detects that there is pressure drop at 1021 both ends of detection resistance, the node device is determined
200 output port 203 has electric current, sends second control signal to the switch module 101, controls the switch module 101
Shut-off, makes the build-out resistor 201 not access bus.At this point, the node device 200 is not the section of the least significant end in bus system
Point device 200, also there is no need to access build-out resistor 201.
In the utility model embodiment, the resistance value of build-out resistor 201 can according to the communication of bus it needs to be determined that, it is optional
, build-out resistor 201 can be 120 ohm, and the utility model does not make limitation to the specific resistance value of build-out resistor 201.
In a kind of specific embodiment, as shown in figure 3, the current detection module 102 can also include current detecting
Amplifier 1023 and control chip 1022, the current sense amplifier 1023 is connected with the output port 203, for detecting
Whether the output port 203 has electric current, and the control chip 1022 is connected with the current sense amplifier 1023.
The control chip 1022 detects that the output port 203 does not have electric current in the current sense amplifier 1023
When, first control signal is sent to the switch module 101, and the switch module 101 is controlled to turn on, makes the build-out resistor
The 201 access buses.
The control chip 1022 detects that the output port 203 has electric current in the current sense amplifier 1023
When, second control signal is sent to the switch module 101, and the switch module 101 is controlled to turn off, makes the build-out resistor
201 do not access the bus.
Current sense amplifier 1023 can be that MAX44284 current sense amplifiers or LTC6102 current detectings are amplified
Device, it is to be understood that current sense amplifier 1023 can not be repeated with other peripheral elements, the application.
The switch module 101 can be triode, transistor or relay switch etc..Certainly, switch module 101 also may be used
Think the device of other forms, control chip 1022 can be received or control the control signal of chip 1022, realize opening for circuit
Pass.
In one embodiment, then as shown in Fig. 2, the switch module 101 be triode, triode include base stage,
Collector and emitter-base bandgap grading, the base stage are connected with control chip 1022 or control chip 1022, the grounded collector, the emitter-base bandgap grading
It is connected with the build-out resistor 201, when the control chip 1022 exports first control signal (such as high level signal, depending on three poles
Depending on the model of pipe) to base stage when, which accesses the bus by the build-out resistor 201.It is appreciated that
It is, when the control chip 1022 exports second control signal (such as low level signal), triode shut-off, so that matching electricity
Resistance 201 does not access bus.
In one embodiment, switch module 101 can also be relay switch, under the control of control chip 1022
Open or close is switched, so that build-out resistor 201 does not access or access bus.
In one embodiment, switch module 101 can also be the on-off circuit of other forms, can realize to matching
The switch control of 201 place circuit of resistance.
Again as shown in Fig. 2, in one embodiment, which can also include indicating module 1024, should
Indicating module 1024 is connected with current detection module 102, when current detection module 102 detects that output port 203 does not have electric current
When, which can emit beam or the standby signal of other forms, to indicate the output terminal of the node device 200
Mouth 203 has prompted staff further to check whether the node device for needing to access matching impedance normally accesses without electric current
Matching impedance, convenient confirmation and verification to endpoint node equipment 200 in bus system.
In conclusion impedance-matching device provided by the embodiments of the present application can be realized to bus system interior joint equipment
The Auto-matching of 200 matching impedance, without manually determining whether node device 200 is endpoint node, is in node device 200
When accessing the endpoint node of bus, switch module 101 can control build-out resistor 201 to be linked into bus.Node device 200 is not
When being endpoint node, build-out resistor 201 will not be linked into bus.So that the faster standard of the configuration of matching impedance in bus
Really, manual operation is reduced, ensures the correct matching of bus widening impedance.Intermediate node damage is avoided to cause to hinder without matching in bus
Anti- situation.
The embodiment of the present application additionally provides a kind of node device 200, as shown in figure 4, applied to bus system, the bus
System includes multiple node devices 200 of serial connection, and each node device 200 includes a bus impedance coalignment 100
And the build-out resistor 201 for accessing bus, the structure of bus impedance coalignment 100 are shown in above-mentioned, which is not described herein again.
The embodiment of the present application additionally provides a kind of bus system, as shown in figure 5, including the node device of at least two series connection
200, wherein, each node device 200 includes an impedance-matching device and the build-out resistor 201 for accessing bus, should
The structure of bus impedance coalignment 100 is shown in above-mentioned, and which is not described herein again.
The above is only the preferred embodiment of the utility model only, is not intended to limit the utility model, for this
For the technical staff in field, various modifications and changes may be made to the present invention.It is all in the spirit and principles of the utility model
Within, any modifications, equivalent replacements and improvements are made should be included within the scope of protection of this utility model.It should be noted that
It arrives：Similar label and letter represents similar terms in following attached drawing, therefore, once determined in a certain Xiang Yi attached drawing
Justice further need not then be defined and explained to it in subsequent attached drawing.
The above is only specific embodiment of the present utility model, but the scope of protection of the utility model is not limited to
In this, in the technical scope that any one skilled in the art discloses in the utility model, variation can be readily occurred in
Or replace, it should be covered within the scope of the utility model.Therefore, the scope of protection of the utility model should be described with power
Subject to the protection domain of profit requirement.
Claims (10)
1. a kind of bus impedance coalignment, which is characterized in that for carrying out impedance matching, the bus system to bus system
Multiple node devices including serial connection, each node device include an impedance-matching device and for accessing bus
Build-out resistor, the bus impedance coalignment include：
The switch module being connected between the build-out resistor and bus；And
Be connected to the node device output port and the switch module between current detection module, the current detecting
Module controls the switch module to turn on according to the output current of the output port, makes the build-out resistor access described total
Line or the control switch module shut-off, make the build-out resistor not access the bus.
2. bus impedance coalignment according to claim 1, which is characterized in that the current detection module includes detection
Resistance and control chip, described detection resistance one end are connected with the output port, other end ground connection, the control chip and institute
Detection resistance connection is stated, to detect the output current of the output port；Wherein：
When the control chip detects that the detection resistance both ends do not have pressure drop, the output port of the node device is determined
There is no electric current, send first control signal to the switch module, the switch module is controlled to turn on, connects the build-out resistor
Enter the bus；
When the control chip detects that there is pressure drop at the detection resistance both ends, determining the output port of the node device has
Electric current sends second control signal to the switch module, the switch module is controlled to turn off, the build-out resistor is made not access
The bus.
3. bus impedance coalignment according to claim 1, which is characterized in that the current detection module includes electric current
Amplifier and control chip are detected, the current sense amplifier is connected with the output port, for detecting the output terminal
Whether mouth has electric current, and the control chip is connected with the current sense amplifier, wherein：
The control chip sends the first control when the current sense amplifier detects that the output port does not have electric current
Signal gives the switch module, and the switch module is controlled to turn on, and the build-out resistor is made to access the bus；
The control chip sends the second control letter when the current sense amplifier detects that the output port has electric current
Number to the switch module, the switch module is controlled to turn off, the build-out resistor is made not access the bus.
4. the bus impedance coalignment according to claims 1 to 3 any one, which is characterized in that the switch module
For triode, transistor, field-effect tube or relay switch.
5. bus impedance coalignment according to claim 4, which is characterized in that the switch module is triode, should
Triode includes base stage, collector and emitter-base bandgap grading, and the base stage is connected with the current detection module, the grounded collector, institute
Emitter-base bandgap grading is stated to be connected with the build-out resistor, wherein：
When the current detection module detects that the output port does not have electric current, output first control signal to the base
Pole controls triode ON, and the build-out resistor is accessed the bus；
When the current detection module detects that the output port has electric current output, output second control signal to the base
Pole, control triode shut-off, makes the build-out resistor not access the bus.
6. bus impedance coalignment according to claim 3, which is characterized in that the model of the current sense amplifier
For MAX44284 current sense amplifiers or LTC6102 current sense amplifiers.
7. bus impedance coalignment according to claim 1, which is characterized in that the device further includes：
It is connected with the current detection module, for whether there is the indicative indicating module of electric current to the output port.
8. bus impedance coalignment according to claim 7, which is characterized in that the indicating module is light-emitting diodes
Pipe.
9. a kind of node device, which is characterized in that applied to bus system, the bus system includes the multiple sections being connected in series
Point device, each node device is including the impedance-matching device described in claim 1-8 any one and for accessing bus
Matching impedance.
10. a kind of bus system, which is characterized in that including at least two be connected in series such as claim 1-8 any one institute
The node device stated.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN201721166312.5U CN207408939U (en) | 2017-09-12 | 2017-09-12 | Bus impedance coalignment, node device and bus system |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721166312.5U CN207408939U (en) | 2017-09-12 | 2017-09-12 | Bus impedance coalignment, node device and bus system |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110519142A (en) * | 2019-08-27 | 2019-11-29 | 江苏沃姆克科技有限公司 | A kind of SF-CAN BUS filter |
| CN112559416A (en) * | 2020-12-07 | 2021-03-26 | 珠海格力电器股份有限公司 | Bus communication control method and device and industrial touch screen |
| CN114253887A (en) * | 2021-12-20 | 2022-03-29 | 上海同星智能科技有限公司 | Impedance matching adapter, impedance matching system and method |
| CN115996156A (en) * | 2023-03-21 | 2023-04-21 | 国仪量子(合肥)技术有限公司 | Bus network system and impedance matching method thereof |
-
2017
- 2017-09-12 CN CN201721166312.5U patent/CN207408939U/en active Active
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110519142A (en) * | 2019-08-27 | 2019-11-29 | 江苏沃姆克科技有限公司 | A kind of SF-CAN BUS filter |
| CN112559416A (en) * | 2020-12-07 | 2021-03-26 | 珠海格力电器股份有限公司 | Bus communication control method and device and industrial touch screen |
| CN112559416B (en) * | 2020-12-07 | 2024-06-14 | 珠海格力电器股份有限公司 | Bus communication control method and device and industrial touch screen |
| CN114253887A (en) * | 2021-12-20 | 2022-03-29 | 上海同星智能科技有限公司 | Impedance matching adapter, impedance matching system and method |
| WO2023116052A1 (en) * | 2021-12-20 | 2023-06-29 | 上海同星智能科技有限公司 | Impedance matching adapter, and impedance matching system and method |
| CN115996156A (en) * | 2023-03-21 | 2023-04-21 | 国仪量子(合肥)技术有限公司 | Bus network system and impedance matching method thereof |
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