CN204256410U - A kind of communication interface circuit and communication apparatus - Google Patents
A kind of communication interface circuit and communication apparatus Download PDFInfo
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- CN204256410U CN204256410U CN201420810442.8U CN201420810442U CN204256410U CN 204256410 U CN204256410 U CN 204256410U CN 201420810442 U CN201420810442 U CN 201420810442U CN 204256410 U CN204256410 U CN 204256410U
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Abstract
The utility model provides a kind of communication interface circuit and communication apparatus, by arranging the first resistance and the second resistance between the Enable Pin and the signal input/output end of MAX232 integrated circuit of MAX485 integrated circuit, thus the level signal avoided between MAX485 integrated circuit and described MAX232 integrated circuit is disturbed, and then make the communication apparatus with this communication interface circuit can be according to actual needs, with RS232 equipment or RS485 equipment connection, thus expand the usable range that this has the communication apparatus of this communication interface circuit.
Description
Technical field
The utility model relates generally to communication data transfer technical field, more particularly relates to a kind of communication interface circuit and communication apparatus.
Background technology
Communication interface is the interface circuit that microcomputer system and other equipment carry out digital communication, and serial communication interface is as a kind of conventional interface circuit, it is mainly used in a low-speed peripheral and is connected with microcomputer, realizes the transmission of of information.
In actual applications, RS232 interface and RS485 interface are two kinds of the most frequently used at present communication interfaces, and be the standard configuration interface that various sensor signal data exports, but, by the restriction of these two kinds of interface own characteristics, the communication apparatus of existing each manufacturer production can only support RS232 interface or RS485 interface, greatly limit the usable range of this communication apparatus.
Utility model content
In view of this, the utility model provides a kind of communication interface circuit and communication apparatus, solves existing equipment and can only support RS232 interface or RS485 interface, and the technical matters making this equipment use range limited.
In order to solve the problems of the technologies described above, the utility model proposes following technical scheme:
A kind of communication interface circuit, comprising: controller, MAX485 integrated circuit, MAX232 integrated circuit, the first resistance and the second resistance, wherein:
Described controller is connected with the enable port of described MAX485 integrated circuit and the signal input port of described MAX232 integrated circuit and signal output port respectively;
One end of described first resistance is connected with the receiver output port of described MAX485 integrated circuit, and the other end is connected with the signal output port of described MAX232 integrated circuit;
One end of described second resistance is connected with the driver input end mouth of described MAX485 integrated circuit, and the other end is connected with the signal input port of described MAX232 integrated circuit.
Preferably, described first resistance and described second resistance are specially the resistance that resistance is 51 ohm.
Preferably, described MAX485 integrated circuit comprises MAX485 interface chip and peripheral circuit thereof;
Then the enable port of described MAX485 integrated circuit comprises: the receiver output enable pin of described MAX485 interface chip and driver output enable pin.
Preferably, described MAX232 integrated circuit comprises MAX3232 interface chip and peripheral circuit thereof;
Then the signal input port of described MAX232 integrated circuit is specially the Transistor-Transistor Logic level input pin of described MAX3232 interface chip, and the signal output port of described MAX232 integrated circuit is specially the Transistor-Transistor Logic level output pin of MAX3232 interface chip.
Preferably, described controller is specially MCU;
Then the 485DIR pin of described MCU is connected with the enable port of described MAX485 integrated circuit, the TxD pin of described MCU is connected with the signal input port of described MAX232 integrated circuit, and the RxD pin of described MCU is connected with the signal output port of described MAX232 integrated circuit.
Preferably, also comprise: the 3rd resistance and the 4th resistance, wherein:
One end of described 3rd resistance is connected with the tie point of the receiver output port of described MAX485 integrated circuit and described first resistance, and the other end is connected with 3.3V power supply;
One end of described 4th resistance is connected with described second ohmic connection points with the driver input end mouth of described MAX485 integrated circuit, and the other end is connected with described 3.3V power supply.
Preferably, described 3rd resistance and described 4th resistance to be resistance the be resistance of 4.7 kilohms.
Preferably, also comprise:
Be used to indicate the first indicating circuit of the connection status of described MAX485 integrated circuit and RS485 equipment;
Be used to indicate the second indicating circuit of the connection status of described MAX232 integrated circuit and RS232 equipment.
Preferably, described first indicating circuit and described second indicating circuit are specially pilot lamp.
A kind of communication apparatus, comprises communication interface circuit as above.
As can be seen here, the utility model provides a kind of communication interface circuit and communication apparatus, by arranging the first resistance and the second resistance between the Enable Pin and the signal input/output end of MAX232 integrated circuit of MAX485 integrated circuit, thus the level signal avoided between MAX485 integrated circuit and described MAX232 integrated circuit is disturbed, and then make the communication apparatus with this communication interface circuit can be according to actual needs, with RS232 equipment or RS485 equipment connection, thus expand the usable range that this has the communication apparatus of this communication interface circuit.
Accompanying drawing explanation
In order to be illustrated more clearly in the utility model embodiment or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is only embodiment of the present utility model, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to the accompanying drawing provided.
Fig. 1 is the structural representation of a kind of communication interface circuit embodiment of the utility model;
Fig. 2 is the circuit connection diagram of a kind of communication interface circuit specific embodiment of the utility model.
Embodiment
Below in conjunction with the accompanying drawing in the utility model embodiment, be clearly and completely described the technical scheme in the utility model embodiment, obviously, described embodiment is only the utility model part embodiment, instead of whole embodiments.Based on the embodiment in the utility model, those of ordinary skill in the art are not making the every other embodiment obtained under creative work prerequisite, all belong to the scope of the utility model protection.
The utility model provides a kind of communication interface circuit and communication apparatus, by arranging the first resistance and the second resistance between the Enable Pin and the signal input/output end of MAX232 integrated circuit of MAX485 integrated circuit, thus the level signal avoided between MAX485 integrated circuit and described MAX232 integrated circuit is disturbed, and then make the communication apparatus with this communication interface circuit can be according to actual needs, with RS232 equipment or RS485 equipment connection, thus expand the usable range that this has the communication apparatus of this communication interface circuit.
With reference to the structural representation of a kind of communication interface circuit of the utility model shown in Fig. 1, this communication interface circuit can be applicable in communication apparatus, with RS232 equipment or RS485 equipment connection, realize Signal transmissions, the communication interface circuit that the present embodiment provides specifically can comprise: controller 100, MAX485 integrated circuit 200, MAX232 integrated circuit 300, first resistance R1 and the second resistance R2, wherein:
Described controller 100 is connected with the enable port of described MAX485 integrated circuit 200 and the signal input port of described MAX232 integrated circuit 200 and signal output port respectively.
One end of described first resistance R1 is connected with the receiver output port of described MAX485 integrated circuit 200, and the other end is connected with the signal output port of described MAX232 integrated circuit 300;
One end of described second resistance R2 is connected with the driver input end mouth of described MAX485 integrated circuit 200, and the other end is connected with the signal input port of described MAX232 integrated circuit 300.
Optionally, this controller 100 is specifically as follows MCU, single-chip microcomputer etc., and the utility model does not do concrete restriction to this, and when this controller 100 is MCU, above-mentioned controller 100 is specifically as follows with the connection of MAX485 integrated circuit 200 and MAX232 integrated circuit 300:
The 485DIR pin of described MCU is connected with the enable port of described MAX485 integrated circuit 200, the TxD pin of described MCU is connected with the signal input port of described MAX232 integrated circuit 300, and the RxD pin of described MCU is connected with the signal output port of described MAX232 integrated circuit 300.
Wherein, the enable port of described MAX485 integrated circuit 200 specifically can comprise receiver output enable port and driver output enable port.
Based on this, in actual applications, if 1 represents that high level, 0 represents low level, then when MCU control its 485DIR pin export 1 time, the enable bus of MAX485 integrated circuit 200 is in accepting state, when this MAX485 integrated circuit 200 accesses RS485 equipment, and during this RS485 equipment sending data, this MAX485 integrated circuit 200 will be converted to TTL (Transistor-Transistor Logic, transistor-transistor logic) level these data.Because the RxD pin of now the receiver output port of MAX485 integrated circuit 200, the signal output port of MAX232 integrated circuit 300 and MCU is effective, if directly the receiver output port of MAX485 integrated circuit 200 is connected with the signal output port of MAX232 integrated circuit 300, the level of two-port is identical and will affect, namely there is signal disturbing, have impact on the reliability of data transmission.
For this reason, the utility model by arranging the first resistance between the receiver output port and the signal output port of MAX232 integrated circuit 300 of MAX485 integrated circuit 200, thus make between two-port, there is certain pressure reduction, reduce signal disturbing, ensure that the RxD pin of MCU can accurately identify 1 or 0.
Optionally, on the basis of above-described embodiment, this communication interface circuit can also comprise the 3rd resistance R3 and the 4th resistance R4, wherein:
One end of described 3rd resistance R3 is connected with the tie point of the receiver output port of described MAX485 integrated circuit 200 and described first resistance R1, and the other end is connected with 3.3V power supply;
One end of described 4th resistance R4 is connected with described second resistance R2 tie point with the driver input end mouth of described MAX485 integrated circuit 200, and the other end is connected with described 3.3V power supply.
Preferably, this first resistance R1 and the second resistance R2 can be all 51 Ω resistance, and the 3rd resistance R3 and the 4th resistance R4 can be all 4.7K Ω resistance, but is not limited thereto, and the utility model can carry out resistance adjustment according to actual needs.
As another embodiment of the utility model, circuit with reference to a kind of communication interface circuit specific embodiment of the utility model shown in Fig. 2 connects figure, on the basis of the embodiment described in above-mentioned Fig. 1, in the present embodiment, above-mentioned MAX485 integrated circuit 200 comprises MAX485 interface chip and peripheral circuit thereof; Then the enable port of described MAX485 integrated circuit comprises: the receiver output enable pin RE of described MAX485 interface chip and driver output enable pin DE.
Wherein, this MAX485 interface chip is a kind of RS-485 chip of Maxim company, and its inside comprises a driver and a receiver, and the low-power consumption transceiver that can be used as RS-485 communication uses.In actual applications, this MAX485 interface chip adopts half duplex communication mode, and when it is operated in half-duplex state, a pin interface control signal of a controller 100 is only needed to receive and send, very simple, in addition, build-out resistor can also be set between A and the B end of this interface chip, as 120 Ω in Fig. 2, be not limited thereto.
In addition, it should be noted that, for the concrete connection of the peripheral circuit of MAX485 integrated circuit 200 in this MAX485 integrated circuit 200 as shown in Figure 2, because it belongs to this area conventional techniques means, those skilled in the art can set according to actual needs, therefore, the utility model is not described further its peripheral circuit, specifically can refer to shown in Fig. 2.
Above-mentioned MAX232 integrated circuit 300 comprises MAX3232 interface chip and peripheral circuit thereof; Then the signal input port of described MAX232 integrated circuit 300 is specially the Transistor-Transistor Logic level input pin TTL_in of described MAX3232 interface chip, and the signal output port of described MAX232 integrated circuit is specially the Transistor-Transistor Logic level output pin TTL_out of MAX3232 interface chip.
Wherein, MAX3232 interface chip adopts proprietary low voltage difference transmitter output stage, utilize dual charge pump to realize real RS-323 performance when 3V ~ 5.5V Power supply, even and if it is under the poorest altogether condition of work, namely under 120kbps data rate, also can keep RS-232 output level simultaneously.
In addition, it should be noted that, the concrete structure for the peripheral circuit in MAX232 integrated circuit 300 belongs to this area conventional techniques means, and those skilled in the art can set according to actual needs, and the utility model is not described in detail in this.
Known based on above-mentioned analysis, the utility model by arranging the first resistance between the receiver output enable pin and the Transistor-Transistor Logic level output pin of MAX3232 interface chip of MAX485 interface chip, and the second resistance is set between the driver output enable pin and the Transistor-Transistor Logic level input pin of MAX3232 interface chip of MAX485 interface chip, thus the level signal avoided between MAX485 integrated circuit and described MAX232 integrated circuit is disturbed, and then make the communication apparatus with this communication interface circuit can be according to actual needs, with RS232 equipment or RS485 equipment connection, thus expand the usable range that this has the communication apparatus of this communication interface circuit.
In addition, the utility model additionally provides a kind of communication apparatus, as telemetering terminal, data acquisition transmission instrument etc., it comprises the communication interface circuit of the description of above-mentioned communication interface circuit embodiment, and other functional circuits, casing etc., thus makes this communication apparatus only can access RS485 equipment, also RS232 equipment can be accessed, as long as asynchronously access, compared with prior art, the usable range of this communication apparatus is substantially increased.
Wherein, the concrete structure for the communication interface circuit in this communication apparatus can refer to the description content of above-described embodiment, and the utility model is not described in detail in this.
It should be noted that, for this communication apparatus inner structure, except above-mentioned each device or circuit, can also comprise link, display or indicating circuit etc., the utility model describes in detail no longer one by one at this.
In this instructions, each embodiment adopts the mode of going forward one by one to describe, and what each embodiment stressed is the difference with other embodiments, between each embodiment identical similar portion mutually see.
To the above-mentioned explanation of the disclosed embodiments, professional and technical personnel in the field are realized or uses the utility model.To be apparent for those skilled in the art to the multiple amendment of these embodiments, General Principle as defined herein when not departing from spirit or scope of the present utility model, can realize in other embodiments.Therefore, the utility model can not be restricted to these embodiments shown in this article, but will meet the widest scope consistent with principle disclosed herein and features of novelty.
Claims (10)
1. a communication interface circuit, is characterized in that, comprising: controller, MAX485 integrated circuit, MAX232 integrated circuit, the first resistance and the second resistance, wherein:
Described controller is connected with the enable port of described MAX485 integrated circuit and the signal input port of described MAX232 integrated circuit and signal output port respectively;
One end of described first resistance is connected with the receiver output port of described MAX485 integrated circuit, and the other end is connected with the signal output port of described MAX232 integrated circuit;
One end of described second resistance is connected with the driver input end mouth of described MAX485 integrated circuit, and the other end is connected with the signal input port of described MAX232 integrated circuit.
2. communication interface circuit according to claim 1, is characterized in that, described first resistance and described second resistance are specially the resistance that resistance is 51 ohm.
3. communication interface circuit according to claim 1, is characterized in that, described MAX485 integrated circuit comprises MAX485 interface chip and peripheral circuit thereof;
Then the enable port of described MAX485 integrated circuit comprises: the receiver output enable pin of described MAX485 interface chip and driver output enable pin.
4. communication interface circuit according to claim 3, is characterized in that, described MAX232 integrated circuit comprises MAX3232 interface chip and peripheral circuit thereof;
Then the signal input port of described MAX232 integrated circuit is specially the Transistor-Transistor Logic level input pin of described MAX3232 interface chip, and the signal output port of described MAX232 integrated circuit is specially the Transistor-Transistor Logic level output pin of MAX3232 interface chip.
5. the communication interface circuit according to any one of claim 1-4, is characterized in that, described controller is specially MCU;
Then the 485DIR pin of described MCU is connected with the enable port of described MAX485 integrated circuit, the TxD pin of described MCU is connected with the signal input port of described MAX232 integrated circuit, and the RxD pin of described MCU is connected with the signal output port of described MAX232 integrated circuit.
6. communication interface circuit according to claim 5, is characterized in that, also comprises: the 3rd resistance and the 4th resistance, wherein:
One end of described 3rd resistance is connected with the tie point of the receiver output port of described MAX485 integrated circuit and described first resistance, and the other end is connected with 3.3V power supply;
One end of described 4th resistance is connected with described second ohmic connection points with the driver input end mouth of described MAX485 integrated circuit, and the other end is connected with described 3.3V power supply.
7. communication interface circuit according to claim 6, is characterized in that, described 3rd resistance and described 4th resistance to be resistance the be resistance of 4.7 kilohms.
8. communication interface circuit according to claim 7, is characterized in that, also comprises:
Be used to indicate the first indicating circuit of the connection status of described MAX485 integrated circuit and RS485 equipment;
Be used to indicate the second indicating circuit of the connection status of described MAX232 integrated circuit and RS232 equipment.
9. communication interface circuit according to claim 8, is characterized in that, described first indicating circuit and described second indicating circuit are specially pilot lamp.
10. a communication apparatus, is characterized in that, comprises the communication interface circuit as described in any one of claim 1-9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420810442.8U CN204256410U (en) | 2014-12-18 | 2014-12-18 | A kind of communication interface circuit and communication apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420810442.8U CN204256410U (en) | 2014-12-18 | 2014-12-18 | A kind of communication interface circuit and communication apparatus |
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| Publication Number | Publication Date |
|---|---|
| CN204256410U true CN204256410U (en) | 2015-04-08 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201420810442.8U Active CN204256410U (en) | 2014-12-18 | 2014-12-18 | A kind of communication interface circuit and communication apparatus |
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| CN (1) | CN204256410U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105488003A (en) * | 2015-11-24 | 2016-04-13 | 上海斐讯数据通信技术有限公司 | Circuit structure and method for enhancing reliability of RS232 communication interface |
| CN107844157A (en) * | 2017-11-15 | 2018-03-27 | 威创集团股份有限公司 | A kind of projector's standby power consumption control circuit, device and equipment |
-
2014
- 2014-12-18 CN CN201420810442.8U patent/CN204256410U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105488003A (en) * | 2015-11-24 | 2016-04-13 | 上海斐讯数据通信技术有限公司 | Circuit structure and method for enhancing reliability of RS232 communication interface |
| CN107844157A (en) * | 2017-11-15 | 2018-03-27 | 威创集团股份有限公司 | A kind of projector's standby power consumption control circuit, device and equipment |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C56 | Change in the name or address of the patentee | ||
| CP01 | Change in the name or title of a patent holder |
Address after: Two road 400030 Chongqing city Shapingba District 98 west 3 attached to a 3 standard factory building 4 layer Patentee after: TOP POINT S&T CO., LTD. Address before: Two road 400030 Chongqing city Shapingba District 98 west 3 attached to a 3 standard factory building 4 layer Patentee before: Chongqing Duobang Technology Development Co., Ltd. |