CN202600690U - Circuit for RS232 and RS485 communication modes - Google Patents
Circuit for RS232 and RS485 communication modes Download PDFInfo
- Publication number
- CN202600690U CN202600690U CN 201220206905 CN201220206905U CN202600690U CN 202600690 U CN202600690 U CN 202600690U CN 201220206905 CN201220206905 CN 201220206905 CN 201220206905 U CN201220206905 U CN 201220206905U CN 202600690 U CN202600690 U CN 202600690U
- Authority
- CN
- China
- Prior art keywords
- interface
- diode
- module
- comparer
- relay
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Mobile Radio Communication Systems (AREA)
Abstract
The utility model discloses a circuit for RS232 and RS485 communication modes. The circuit comprises a master control module, an RS232 interface, an RS485 interface, a detection module and a switching module, wherein the detection module is used for detecting the interface voltage of the RS232 interface; and the switching module is respectively connected with the master control module, the RS232 interface, the RS485 interface and the detection module. When the RS232 interface is not connected with external communication equipment, the switching module carries out circuit switching, so that the master control module and the RS485 interface establish communication; and when the RS232 interface is connected with the external communication equipment, the switching module carries out circuit switching, so that the master control module and the RS232 interface establish communication. By the circuit, the problem in the prior art that the RS232 and RS485 communication modes cannot be switched is solved, and the switching accuracy and reliability of the RS232 and RS485 communication modes are improved.
Description
Technical field
The utility model relates to circuit field, in particular to a kind of circuit that is used for RS232 and RS485 communication modes.
Background technology
At present; Technology of serial communication has been widely used in the middle of communication, computing machine networking and the industrial control field, is used to realize the data transmission between microcontroller and computing machine, the microcontroller, and serial communication mode commonly used is RS232; RS485, so often provide two kinds of interfaces to be used for communication in the equipment.But in practical application, because the number of ports quantitative limitation, the serial communication transmission mode trends towards requiring RS232 and the RS485 interface can compatibility gradually, and two kinds of transmission modes can realize freely switching.At present, RS232 that uses always in the prior art and the changing method of RS485 are following:
1. adopt the mode of wire jumper or toggle switch to realize switching;
2. adopt the software detection mode, promptly pass through the switching of software programming interface;
3. adopt line and mode, for example the receiving end of hybrid interface is realized line and function through diode;
4. realize the automatic switchover of two kinds of patterns through detecting the RS485 signal;
5. use special-purpose UART Universal Asynchronous Receiver Transmitter (Universal Asynchronous Receiver Transmitter is called for short UART) controller, realize the automatic switchover of RS232 and RS485 interface.
Though prior art can realize the switching of two kinds of transmission modes, also comes with some shortcomings:
1, adopt the mode of wire jumper or toggle switch: this method control trouble, need select artificially, operational error appears easily.
2, adopt the software detection mode: though this method can realize switching, portability is poor, and can take the I/O of system resource.
3, adopt line and mode: get involved though this method need not manpower, simple line and mode can make RS232 and RS485 signal when communication, interact, and the phenomenon of loss of data when the high bit rate, occurs.
4, switch two kinds of patterns through detecting the RS485 signal: this method can realize automaticallying switch, because RS485 belongs to differential signal, so reliability is relatively poor.
5. use special-purpose UART controller: the method dirigibility is high, good reliability, but need use professional chip, cost is too high, and RS485 full duplex interface in most cases can not be provided, and is also inapplicable in general occasion.
Problem to can not be well in the correlation technique RS232 and RS485 communication modes being switched does not propose effective solution at present as yet.
The utility model content
The fundamental purpose of the utility model is to provide the circuit of a kind of RS232 of being used for and RS485 communication modes, to solve in the prior art problem of can not be well RS232 and RS485 communication modes being switched.
To achieve these goals,, the circuit of a kind of RS232 of being used for and RS485 communication modes is provided, has comprised: main control module according to the utility model; The RS232 interface; The RS485 interface; Detection module, the input end is connected with the RS232 interface; And handover module, first end is connected with main control module, and second end is connected with the RS232 interface; The 3rd end is connected with the RS485 interface, and the 4th end is connected with the signal output part of detection module, and first end of handover module is connected with second end or the 3rd end; When the voltage of RS232 interface is zero; First end is connected with the 3rd end, and when the voltage of RS232 interface was non-zero, first end was connected with second end.
Further, detection module comprises window comparator.
Further, window comparator comprises: first comparer, and the electrode input end of first comparer is connected in first reference voltage; Second comparer; The negative input of second comparer is connected in second reference voltage; The electrode input end of second comparer is connected in the negative input of first comparer, and the node between the negative input of the electrode input end of second comparer and first comparer is the input end; First diode, the anode of first diode is connected in the output terminal of first comparer; And second diode, the anode of second diode is connected in the output terminal of second comparer, and the negative electrode of second diode is connected in the negative electrode of first diode, and the node between the negative electrode of the negative electrode of second diode and first diode is a signal output part.
Further, handover module comprises: direct voltage source; Relay, the moving contact of relay is connected with first end, and first stationary contact of relay is connected with second end, and second stationary contact of relay is connected with the 3rd end, and first end of the control coil of relay is connected with direct voltage source; The 3rd diode, the negative electrode of the 3rd diode is connected in first node, and the anode of the 3rd diode is connected in second end of the control coil of relay, and wherein, first node is first end and the node between the direct voltage source of the control coil of relay; Triode, the collector of triode is connected with Section Point, and the base stage of triode is connected with the 4th end, the grounded emitter of triode, wherein, Section Point is second end and the node between the 3rd diode of the control coil of relay; And current-limiting resistance, be connected between the base stage and the 4th end of triode.
Further, the circuit that is used for RS232 and RS485 communication modes also comprises: the RS232 modular converter is connected between second end of RS232 interface and handover module; The RS485 modular converter is connected between the 3rd end of RS485 interface and handover module; And isolation module, be connected between first end and main control module of handover module, and be connected with the RS485 modular converter.
Further, the enable signal of main control module is through the enable signal input end that is connected to the RS485 modular converter of isolation module.
Further, the RS232 modular converter comprises the MAX232 chip.
Further, the RS485 modular converter comprises the MAX485 chip.
The circuit that provides through the utility model; Be employed between main control module and the communication interface handover module be set, and with the detection module that handover module is connected with the RS232 interface, can make when the RS232 interface does not connect external communications equipment; The interface voltage that detection module detects the RS232 interface is zero; This moment, first end of handover module was connected with its 3rd end, that is, main control module is set up communication with the RS485 interface and is connected; When the RS232 interface connected external communications equipment, detection module detected the interface voltage non-zero of RS232 interface, and this moment, first end of handover module was connected with its second end; That is, main control module is set up communication with the RS232 interface and is connected, and has realized need not wire jumper or toggle switch; Through adopting the hardware switching mode; Need not software control, reached and switched the effect timely, accurate, that reliability is high, and data transmission is stable; Solved in the prior art problem of can not be well RS232 and RS485 communication modes being switched, and then reached and improve RS232 and the switching accuracy of RS485 communication modes and the effect of reliability.
Description of drawings
The accompanying drawing that constitutes the application's a part is used to provide the further understanding to the utility model, and illustrative examples of the utility model and explanation thereof are used to explain the utility model, do not constitute the improper qualification to the utility model.In the accompanying drawings:
Fig. 1 is the synoptic diagram according to the circuit of the utility model embodiment;
Fig. 2 is the circuit diagram according to the detection module of the circuit of the utility model embodiment;
Fig. 3 is the circuit diagram according to the handover module of the circuit of the utility model embodiment;
Fig. 4 is the synoptic diagram according to the circuit of the utility model preferred embodiment;
Fig. 5 is the circuit diagram according to the isolation module of the circuit of the utility model preferred embodiment;
Fig. 6 is the circuit diagram according to the RS232 modular converter of the circuit of the utility model preferred embodiment; And
Fig. 7 is the circuit diagram according to the RS485 modular converter of the circuit of the utility model preferred embodiment.
Embodiment
Need to prove that under the situation of not conflicting, embodiment and the characteristic among the embodiment among the application can make up each other.Below with reference to accompanying drawing and combine embodiment to specify the utility model.
The utility model embodiment provides the circuit of a kind of RS232 of being used for and RS485 communication modes, below the circuit that is used for RS232 and RS485 communication modes that the utility model embodiment is provided introduce.
Fig. 1 is the synoptic diagram according to the circuit of the utility model embodiment.
As shown in Figure 1, the circuit that is used for RS232 and RS485 communication modes of this embodiment comprises main control module 10, RS232 interface 20, RS485 interface 30, detection module 40 and handover module 50.Main control module 10 is connected with first end of handover module 50; Second end of handover module 50 is connected with RS485 interface 30 with RS232 interface 20 respectively with the 3rd end; The input end of detection module 40 is connected with RS232 interface 20, is used to detect the interface voltage of RS232 interface 20, and the signal output part of detection module 40 is connected with the 4th end of handover module 50; So that detected interface voltage is sent to handover module 50; First end of handover module 50 is connected with second end or the 3rd end, and when interface voltage was zero, first end and the 3rd end of handover module 50 connected; When the interface voltage non-zero, first end and second end of handover module 50 connect.
Through between main control module and communication interface, handover module being set; And the detection module that is connected with the RS232 interface with handover module; When the RS232 interface did not connect external communications equipment, the interface voltage that detection module detects the RS232 interface was zero, and this moment, first end of handover module was connected with its 3rd end; That is, main control module is set up communication with the RS485 interface and is connected; When the RS232 interface connected external communications equipment, detection module detected the interface voltage non-zero of RS232 interface, and this moment, first end of handover module was connected with its second end; That is, main control module is set up communication with the RS232 interface and is connected, and has realized need not wire jumper or toggle switch; Through adopting the hardware switching mode; Need not software control, reached and switched the effect timely, accurate, that reliability is high, and data transmission is stable; Solved in the prior art problem of can not be well RS232 and RS485 communication modes being switched, and then reached and improve RS232 and the switching accuracy of RS485 communication modes and the effect of reliability.
Particularly, the circuit diagram of detection module 40 and handover module 50 is respectively shown in Fig. 2 and Fig. 3.
As shown in Figure 2, detection module 40 comprises by comparer U2, the window comparator that U3 and diode D1, D2 etc. form; Wherein, the electrode input end of U2 meets voltage U ref1, and negative input is connected with the electrode input end of U3; And be connected in the RXD signal, and the RXD signal is the interface voltage signal of RS232 interface, the negative input of U3 meets voltage U ref2; The output out port of U2, U3 connects the anode of diode D1, D2 respectively, and the negative electrode of D1, D2 links to each other, and joins with the RXD_OUT signal.Uref1, Uref2 are the threshold voltage of comparer, and Uref1＜0, Uref2＞0.Its transport property is: when RXD＜Uref1, U1 exports high level, the D1 conducting, and D2 ends; Output signal RXD_OUT is ' 1 ', when Uref1＜RXD＜Uref2, and U1, the equal output low level of U2, D1, D2 end; Output signal RXD_OUT is ' 0 ', and when RXD＞Uref2, U2 exports high level; The D2 conducting, D1 ends, and output signal RXD_OUT is ' 1 '.Hence one can see that; When the RS232 interface is in idle state; When promptly this mouth was not connected with outside RS232 interface, the signal condition of RXD was 0V, sent into testing circuit and Uref1, Uref2 compares; Obtaining testing circuit output signal RXD_OUT is ' 0 ', and the current RS232 of employing communication pattern is described; When the RS232 interface docks with peripheral hardware RS232 interface, the signal condition of RXD is ± 3V～± 15V, be admitted to testing circuit and threshold value compares, obtaining testing circuit output signal RXD_OUT is ' 1 ', and current employing RS232 communication pattern is described.
As shown in Figure 3, handover module is by relay U4, triode Q1; Diode D3 and related device are formed, and wherein the RXD_OUT of R1 one termination signal detection module holds, the base stage of another termination Q1; The grounded emitter of Q1, the collector of Q1 connects the anode of diode D3, succeeds the V-end of electrical equipment U4 simultaneously; The V+ end of U4 links to each other with the negative electrode of D3, and joins with direct voltage source+VCC.The RXD signal of CPU links to each other with the moving contact pin of U4 (O1 pin), and the stationary contact pin (B1 pin) of U4 is connected to the RS232 interface, and another stationary contact pin (A1 pin) of U4 is connected to the RS485 interface.
RXD_OUT is ' 0 ' when testing circuit output signal, and promptly the RS232 interface does not connect external communications equipment, when not adopting the RS232 communication pattern; Triode Q1 can not conducting; And then relay U4 akinesia, relay still keeps virgin state, and the moving contact of relay U4 closes on the stationary contact A1; Make ISO_RXD link to each other with 485_RXD and the 232_RXD disconnection, connect CPU and RS485 circuit; RXD_OUT is ' 1 ' when testing circuit output signal, and promptly the RS232 interface connects external communications equipment, when adopting the RS232 communication pattern; Triode Q1 conducting; And then relay U4 action, the moving contact of relay U4 closes on the stationary contact B1, makes ISO_RXD and 485_RXD break off; Link to each other with 232_RXD, state is switched to CPU link to each other with the RS232 circuit.Therefore, synchronization has only a kind of communication pattern, the reliability when having guaranteed data transmission.
Fig. 4 is the synoptic diagram according to the circuit of the utility model preferred embodiment; As shown in Figure 4; The preferred embodiment be used for RS232 compares the utility model the foregoing description with the circuit of RS485 communication modes circuit; The two difference is that in the utility model preferred embodiment, the circuit that is used for RS232 and RS485 communication modes also comprises isolation module, RS232 level switch module and RS485 level switch module.
Particularly, the circuit diagram of isolation module is as shown in Figure 5, is made up of isolating chip U1 and related device, in the main control module 10 CPU " TXD "; " RXD ", " RTS " signal after buffer circuit is isolated respectively corresponding conversion be ISO_TXD, ISO_RXD; The ISO_RTS signal, wherein, ISO_TXD is used to be connected RS232 with ISO_RXD; The enable signal end that the receiving and transmitting signal circuit of RS485, ISO_RTS are used to connect RS485 realizes that with control RS485 number of collection of letters or signalling transmitting-receiving is switched fast.
The circuit diagram of the circuit diagram of RS232 level switch module and RS485 level switch module is respectively shown in Fig. 6 and Fig. 7; As shown in Figure 6; The RS232 level switch module comprises MAX232 chip U5 and relevant capacitor, and wherein, the R1OUT pin of MAX232 chip is connected with the B1 pin of handover module; The T1IN pin is connected with the ISO_TXD signal output pin of isolation module; The T1OUT pin and the R1IN pin of MAX232 chip are connected to the RS232 interface, and MAX232 chip U5 carries out communication through pin R1OUT and T1IN and main control module 10, and MAX232 chip U5 carries out communication through pin T1OUT and R1IN and external communications equipment; As shown in Figure 7; The RS485 level switch module comprises MAX485 chip U6 and relevant capacitor; Wherein, The RO pin of MAX485 chip is connected with the A1 pin of handover module; The A pin and the B pin of MAX485 chip are connected to the RS485 interface; The DE of MAX485 chip is connected with the output terminal ISO_RTS of isolating chip with
pin so that main control module adopts the RTS signal that the RS485 interface is controlled, and realizes that transmitting-receiving is switched fast, and the DI pin of MAX485 chip is connected with the ISO_TXD signal output pin of isolation module; MAX485 chip U6 carries out communication through pin RO and DI and main control module 10, and MAX485 chip U6 carries out communication through pin A and B and external communications equipment.
From above description, can find out, through the circuit of the utility model embodiment; When external communications equipment connected the RS232 interface, commutation circuit can automatically switch to according to the testing result of testing circuit on the RS232 communication pattern, and the RS485 circuit is broken off; Otherwise, then break off RS232, connect RS485; Stable, interference-free during with the assurance data transmission.In addition, this automatic switch-over circuit need not wire jumper or toggle switch, and the user uses very convenient.The 3rd, this programme adopts the hardware switching mode, need not software control, and switching is timely, accurate, reliability is high.
The preferred embodiment that the above is merely the utility model is not limited to the utility model, and for a person skilled in the art, the utility model can have various changes and variation.All within the spirit and principle of the utility model, any modification of being done, be equal to replacement, improvement etc., all should be included within the protection domain of the utility model.
Claims (8)
1. a circuit that is used for RS232 and RS485 communication modes is characterized in that, comprising:
Main control module;
The RS232 interface;
The RS485 interface;
Detection module, the input end is connected with said RS232 interface; And
Handover module, first end is connected with said main control module, and second end is connected with said RS232 interface; The 3rd end is connected with said RS485 interface, and the 4th end is connected with the signal output part of said detection module, wherein; When the voltage of said RS232 interface is zero; Said first end is connected with said the 3rd end, and when the voltage of the RS232 of institute interface was non-zero, said first end was connected with said second end.
2. circuit according to claim 1 is characterized in that said detection module comprises window comparator.
3. circuit according to claim 2 is characterized in that, said window comparator comprises:
First comparer, the electrode input end of said first comparer is connected in first reference voltage;
Second comparer; The negative input of said second comparer is connected in second reference voltage; The electrode input end of said second comparer is connected in the negative input of said first comparer, and the node between the negative input of the electrode input end of said second comparer and said first comparer is said input end;
First diode, the anode of said first diode is connected in the output terminal of said first comparer; And
Second diode; The anode of said second diode is connected in the output terminal of said second comparer; The negative electrode of said second diode is connected in the negative electrode of said first diode, and the node between the negative electrode of the negative electrode of said second diode and said first diode is said signal output part.
4. circuit according to claim 1 is characterized in that, said handover module comprises:
Direct voltage source;
Relay; The moving contact of said relay is connected with said first end; First stationary contact of said relay is connected with said second end, and second stationary contact of said relay is connected with said the 3rd end, and first end of the control coil of said relay is connected with said direct voltage source;
The 3rd diode; The negative electrode of said the 3rd diode is connected in first node; The anode of said the 3rd diode is connected in second end of the control coil of said relay, and wherein, said first node is first end and the node between the said direct voltage source of the control coil of said relay;
Triode; The collector of said triode is connected with Section Point, and the base stage of said triode is connected the grounded emitter of said triode with said the 4th end; Wherein, said Section Point is second end and the node between said the 3rd diode of the control coil of said relay; And
Current-limiting resistance is connected between the base stage and said the 4th end of said triode.
5. circuit according to claim 1 is characterized in that, also comprises:
The RS232 modular converter is connected between second end of said RS232 interface and said handover module;
The RS485 modular converter is connected between the 3rd end of said RS485 interface and said handover module; And
Isolation module is connected between first end and said main control module of said handover module, and is connected with said RS485 modular converter.
6. circuit according to claim 5 is characterized in that, the enable signal of said main control module is connected to the enable signal input end of said RS485 modular converter through said isolation module.
7. circuit according to claim 5 is characterized in that, said RS232 modular converter comprises the MAX232 chip.
8. circuit according to claim 5 is characterized in that, said RS485 modular converter comprises the MAX485 chip.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220206905 CN202600690U (en) | 2012-05-09 | 2012-05-09 | Circuit for RS232 and RS485 communication modes |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220206905 CN202600690U (en) | 2012-05-09 | 2012-05-09 | Circuit for RS232 and RS485 communication modes |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202600690U true CN202600690U (en) | 2012-12-12 |
Family
ID=47318214
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201220206905 Expired - Fee Related CN202600690U (en) | 2012-05-09 | 2012-05-09 | Circuit for RS232 and RS485 communication modes |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202600690U (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104298212A (en) * | 2014-10-31 | 2015-01-21 | 上海斐讯数据通信技术有限公司 | RS232 and RS485 compatible system |
| CN105045740A (en) * | 2015-05-27 | 2015-11-11 | 北京立华莱康平台科技有限公司 | Conversion method and circuit for communication interfaces |
| CN107273320A (en) * | 2016-04-08 | 2017-10-20 | 中兴通讯股份有限公司 | A kind of adaptive multiplexer of communication interface hardware and method |
| CN108182166A (en) * | 2018-01-25 | 2018-06-19 | 深圳市朗仁科技有限公司 | Serial ports channel selection circuit and with its vehicular data acquisition box |
| CN109117400A (en) * | 2018-08-09 | 2019-01-01 | 深圳市宏电技术股份有限公司 | A kind of interface automatic switching control equipment and method |
| CN109698710A (en) * | 2017-10-20 | 2019-04-30 | 中国航天科工飞航技术研究院动力供应站 | Data transmission terminal based on LoRa and the communication system with it |
| CN111413906A (en) * | 2020-04-10 | 2020-07-14 | 广州保得威尔电子科技股份有限公司 | Multi-channel interface card |
| CN111694779A (en) * | 2020-06-18 | 2020-09-22 | 京东方科技集团股份有限公司 | Interface switching device, communication equipment and interface switching method |
| CN112865984A (en) * | 2020-12-31 | 2021-05-28 | 深圳市共济科技股份有限公司 | Communication interface switching circuit and switching method thereof |
| CN114063506A (en) * | 2021-11-12 | 2022-02-18 | 罗森伯格技术有限公司 | Device for switching communication modes |
-
2012
- 2012-05-09 CN CN 201220206905 patent/CN202600690U/en not_active Expired - Fee Related
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104298212A (en) * | 2014-10-31 | 2015-01-21 | 上海斐讯数据通信技术有限公司 | RS232 and RS485 compatible system |
| CN105045740A (en) * | 2015-05-27 | 2015-11-11 | 北京立华莱康平台科技有限公司 | Conversion method and circuit for communication interfaces |
| CN107273320A (en) * | 2016-04-08 | 2017-10-20 | 中兴通讯股份有限公司 | A kind of adaptive multiplexer of communication interface hardware and method |
| CN109698710A (en) * | 2017-10-20 | 2019-04-30 | 中国航天科工飞航技术研究院动力供应站 | Data transmission terminal based on LoRa and the communication system with it |
| CN108182166A (en) * | 2018-01-25 | 2018-06-19 | 深圳市朗仁科技有限公司 | Serial ports channel selection circuit and with its vehicular data acquisition box |
| CN109117400A (en) * | 2018-08-09 | 2019-01-01 | 深圳市宏电技术股份有限公司 | A kind of interface automatic switching control equipment and method |
| CN109117400B (en) * | 2018-08-09 | 2021-01-05 | 深圳市宏电技术股份有限公司 | Automatic interface switching device and method |
| CN111413906A (en) * | 2020-04-10 | 2020-07-14 | 广州保得威尔电子科技股份有限公司 | Multi-channel interface card |
| CN111694779A (en) * | 2020-06-18 | 2020-09-22 | 京东方科技集团股份有限公司 | Interface switching device, communication equipment and interface switching method |
| US11853247B2 (en) | 2020-06-18 | 2023-12-26 | Boe Technology Group Co., Ltd. | Interface switching apparatus, communication device, and interface switching method |
| CN112865984A (en) * | 2020-12-31 | 2021-05-28 | 深圳市共济科技股份有限公司 | Communication interface switching circuit and switching method thereof |
| CN114063506A (en) * | 2021-11-12 | 2022-02-18 | 罗森伯格技术有限公司 | Device for switching communication modes |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN202600690U (en) | Circuit for RS232 and RS485 communication modes | |
| CN101860288B (en) | Intelligent controller for three-phase motor | |
| CN109714235B (en) | Non-polar RS485 communication interface and method for realizing non-polar RS485 communication | |
| CN207926616U (en) | A kind of meter bus communication circuit device | |
| CN204929366U (en) | DALI interface circuit | |
| CN203933666U (en) | A kind of CAN bus repeater | |
| CN103532541A (en) | Light module power supply control method and system | |
| CN107273320A (en) | A kind of adaptive multiplexer of communication interface hardware and method | |
| CN100565230C (en) | CAN bus broken circuit detection circuit and method thereof | |
| CN111092739B (en) | Dynamic adjusting method for power consumption of switch | |
| CN209526733U (en) | A kind of nonpolarity RS485 communication interface | |
| CN203275994U (en) | Energy-saving control system based on power carrier wave and ZIGBEE network technologies | |
| CN109376109A (en) | Multiple serial communication switching device | |
| CN204009870U (en) | A kind of RS485 serial ports automatic transceiving is controlled and indicating circuit | |
| CN101360050B (en) | Method and apparatus setting flow control mode | |
| CN201345392Y (en) | Network system used in electric automobile battery charger | |
| CN109687863A (en) | The driving circuit of RS485 chip | |
| CN109800201A (en) | The driving method of RS485 real-time tranception control based on linux | |
| CN109117400A (en) | A kind of interface automatic switching control equipment and method | |
| CN109194322A (en) | RS485 high speed communication condenser type isolation circuit and its performance test methods | |
| CN201072433Y (en) | CAN bus open circuit detection circuit | |
| CN213957869U (en) | Internet gateway circuit | |
| CN205059304U (en) | Detection apparatus for battery charging outfit connection status and electric automobile | |
| CN203164750U (en) | M-BUS bus monitoring circuit | |
| CN213843820U (en) | Controller network device of breaker operating mechanism detection system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20121212 Termination date: 20170509 |