CN201314678Y

CN201314678Y - 485 bus circuit and line control device with 485 bus circuit

Info

Publication number: CN201314678Y
Application number: CNU200820226569XU
Authority: CN
Inventors: 陈建兵
Original assignee: Hisense Shandong Air Conditioning Co Ltd
Current assignee: Hisense Shandong Air Conditioning Co Ltd
Priority date: 2008-12-12
Filing date: 2008-12-12
Publication date: 2009-09-23
Anticipated expiration: 2018-12-12

Abstract

The utility model discloses a 485 bus circuit and a line control device with the 485 bus circuit, the 485 bus circuit comprises a controller and 485 bus chips, the 485 bus chips include two, a pair of differential signal terminals are contained in each 485 bus chip, and two differential signal terminals of the 485 bus chips are in cross connection according to the polarity and then are connected with a bus interface; moreover, operating mode control terminals of the 485 bus chips receive the command signals sent by the controller respectively, and control the operation of one of the 485 bus chips according to the plug-in connection condition of an external bus. The 485 bus circuit in the utility model realizes the non-polarity design of the 485 bus in a simple structural mode. The 485 bus circuit can be applied to the line control device, particularly to a line control device for a central air condition system, can improve the efficiency of installation and maintenance of the central air condition system, improves the reliability and the commonality of the line control device, and reduces the development types of the products.

Description

A kind of 485 bus circuits and have the line control machine of described circuit

Technical field

The utility model belongs to the bus circuit technical field, specifically, relates to a kind of 485 bus circuits of nonpolarity restriction and based on the line control machine of described nonpolarity 485 bus circuits.

Background technology

Existing idle call line control machine adopts 485 buses to carry out transfer of data mostly.But,, therefore cause 485 buses to have polarity owing to all adopt the differential data form by the data of 485 bus transfer.In the more occasion of line control machine number of applications, such as central air conditioner system, install and maintenance process in be easy to because incorrect polarity and cause whole system to take place unusually during the order wire wiring.If can be nonpolarity, the installation and maintenance of central air conditioner system will be made things convenient for greatly with 485 bus designs.

Simultaneously, present line control machine generally all adopts the host computer power supply, because host computer and line control machine distance are far away, therefore, power supply quality is relatively poor, is subjected to the interference of periphery electromagnetic environment easily.If can on existing line control machine, increase the miniaturization Switching Power Supply, make the line control machine can be directly from the civil power power taking, not only can improve the power quality of line control machine like this, but also can allow line control machine directly drive some executing agencies according to actual needs, to alleviate the burden of host computer.

The utility model content

The utility model is in order to solve the existing 485 bus circuits problem that easy generation leads to system abnormity because of wiring error because having polarity, a kind of novel nonpolarity 485 bus circuits are provided, make things convenient for the wiring operation, improved the installation and maintenance efficient of system.

For solving the problems of the technologies described above, the utility model is achieved by the following technical solutions:

A kind of 485 bus circuits, comprise controller and 485 bus chips, described 485 bus chips comprise two, all include 1 pair of differential signal end in each 485 bus chip, the two paths of differential signals end of two 485 bus chips (is the negative polarity end that the positive ends of first 485 bus chip connects second 485 bus chip after according to the polarity interconnection; The negative polarity end of first 485 bus chip connects the positive ends of second 485 bus chip), be connected with EBI.In addition, the duty control end of described two 485 bus chips receives the command signal that described controller sends respectively, and then controls one of them 485 bus chip work according to the grafting situation of external bus, to mate the polarity of outside 485 buses.

Further, the data sending terminal of described two 485 bus chips is connected the data transmitting pin of described controller with optical coupling isolation circuit by No. one drive circuit; The data of described controller receive pin by other No. one drive circuit and data receiver corresponding be connected of optical coupling isolation circuit with two 485 bus chips.

Further again, in order to save the pin resource of controller, described controller generates the output of 4 tunnel control signals by its two-way I/O mouth output two-way command signal through a logic circuit; In each 485 bus chip, its duty control end all includes two-way: the one tunnel receives Enable Pin, and riches all the way send Enable Pin; Corresponding 4 tunnel control signals that receive described logic circuit output of 4 tunnel duty control ends of described two 485 bus chips.

Further again, described two-way command signal connects optical coupling isolation circuit by No. one drive circuit separately, carry out exporting described logic circuit to after photoelectricity is isolated, and then generate 4 tunnel control signals and export two 485 bus chips to, and then control one 485 bus chip and enter high-impedance state, another 485 bus chip enters transmission state or accepting state.

Based on above-mentioned 485 bus circuit structures, the utility model provides a kind of line control machine with described 485 bus circuits again, by two 485 bus chips are set in line control machine, and with its differential signal end interconnection, and then under the control of controller, select one of them 485 bus chip work, to mate the wiring polarity of outside 485 buses.So, external bus is when connecting described line control machine, need not to consider wiring polarity, only need be plugged on the EBI and get final product, line control machine is inner can finish matching process automatically according to the wiring polarity of the bus of being pegged graft, thereby greatly made things convenient for the wiring operation, improved the installation and maintenance efficient of system.

Further, in order to improve power supply quality, in described line control machine, also include independently power circuit, receive the external communication power supply by AC power supply jack, after it was carried out rectification, filtering, step-down and handle, generating the multichannel low-voltage dc power supply was the modular circuit power supply that needs low-voltage DC supply in the line control machine.

Further again, also include multicircuit relay in described line control machine, an end of its coil connects low-voltage dc power supply, and the other end is by the switch ways ground connection of on-off circuit, the control end of described on-off circuit receives the control signal of controller output, with the on off operating mode of control relay; The normally opened contact of described relay is connected between the fire-wire interfaces that is provided with on one of them terminal of AC power supply jack of line control machine and the line control machine, and is controlled when closed at relay, provides the interchange live wire to external equipment.So, can make line control machine possess the function that drives some executing agency, to alleviate the burden of external system.

Compared with prior art, advantage of the present utility model and good effect are: 485 bus circuits of the present utility model have realized the nonpolarityization design of 485 buses with simple version.Be applied in the line control machine, particularly central air conditioner system can improve the installation and maintenance efficient of central air conditioner system with in the line control machine, and the reliability of enhancing line control machine and universal reduces the Products Development kind.

After reading the detailed description of the utility model embodiment in conjunction with the accompanying drawings, other characteristics of the present utility model and advantage will become clearer.

Description of drawings

Fig. 1 is the circuit theory diagrams of a kind of embodiment of the line control machine middle controller that proposes of the utility model;

Fig. 2 is the circuit theory diagrams of a kind of embodiment of keyboard scanning circuit;

Fig. 3 is the circuit theory diagrams of a kind of embodiment of remote-control receiving circuit;

Fig. 4 is the circuit theory diagrams of a kind of embodiment of electrify restoration circuit and Tao Zhen circuit;

Fig. 5 is the circuit theory diagrams of a kind of embodiment of memory circuit and UART telecommunication circuit;

Fig. 6 is the circuit theory diagrams of a kind of embodiment of display drive circuit;

Fig. 7 is the circuit theory diagrams of a kind of embodiment of relay drive circuit;

Fig. 8 is the circuit theory diagrams of a kind of embodiment of nonpolarity 485 bus circuits;

Fig. 9 is the circuit theory diagrams of a kind of embodiment of strong power part in the line control machine.

The specific embodiment

Below in conjunction with accompanying drawing the specific embodiment of the present utility model is described in detail.

The mentality of designing of 485 bus circuits that the utility model proposed is: the transceiver channel that adopts one 485 bus data of two 485 bus chip designs; Wherein, in each 485 bus chip, all include 1 pair of differential signal end, with the two paths of differential signals end of two 485 bus chips according to the polarity interconnection, shared 1 pair of differential signal order wire, the positive ends that is about to first 485 bus chip is connected with the negative polarity end of second 485 bus chip; The negative polarity end of first 485 bus chip is connected with the positive ends of second 485 bus chip, and then by common order wire junctor highway interface.In addition, duty control end by two 485 bus chips receives the command signal that controller sends, and then control one of them 485 bus chip work according to the grafting situation of external bus, another 485 bus chip is in high-impedance state, realize coupling with outside 485 bus terminals polarity with this, reach the peg graft purpose of design of nonpolarity requirement of 485 bus circuits.

Be the concrete composition structure and the course of work that example elaborates described 485 bus circuits with the central air-conditioning line control machine below.

Embodiment one, referring to shown in Figure 1, in the present embodiment, selected controller IC 6 can specifically adopt 8 high-performance microprocessor MCU to realize in the line control machine, not only pin aboundresources, and cost is lower, can satisfy the needs of multiple small controller.

Controller IC 6 is as the core component in the line control machine, undertaking centralized management and control action to each function module circuit in the weak current part, connect keyboard scanning circuit, remote-control receiving circuit, display drive circuit, memory circuit, UART telecommunication circuit and 485 bus circuits etc. in the line control machine respectively, to realize the collaborative work requirement between each modular circuit.

Fig. 2 is the circuit theory diagrams of a kind of embodiment of described keyboard scanning circuit, comprises the key switch S1～S13 of a plurality of representative different operating functions.Described key switch S1～S13 connects with matrix form, and an end connects low-voltage dc power supply by pull-up resistor R42～R45, such as shown in Figure 2+5V dc source, and connects 4 road I/O mouth: P4.3～P4.6 of described controller IC 6 by resistance R 46～R49; Other 4 road I/O mouth: P3.4, P3.5, P4.1, the corresponding connection of P4.2 of the other end and described controller IC 6.Controller IC 6 adopts the dynamic keyboard scanning technique, in real time described key circuit is scanned, to receive the user by triggering the control instruction of button input.

Fig. 3 is the circuit theory diagrams of a kind of embodiment of remote-control receiving circuit, comprise that infrared remote control receives an IC3, after the infrared signal that the user is sent by remote controller is decoded, be sent to described controller IC 6 by its output OUT and handle, with response user operation.In order to improve reliability of data transmission, receive at described infrared remote control also be connected with on the output OUT of an IC3 by resistance R 52 and+draw branch road on the voltage that the 5V dc source is formed.

Fig. 4 is the circuit theory diagrams of a kind of embodiment of electrify restoration circuit and Tao Zhen circuit.Wherein, in described reset circuit, include the chip IC4 that resets, by the supply voltage of supervisory control device IC6, such as among Fig. 1 be controller IC 6 power supplies+the 5V DC voltage, generate the start reset signal, can operate as normal to guarantee controller IC 6.In addition, the Xin of described controller IC 6, Xout pin connect Tao Zhen chip X1, are used for providing reference clock accurately to controller IC 6.

Fig. 5 is the circuit theory diagrams of a kind of embodiment of memory circuit and UART telecommunication circuit.Wherein, in described memory circuit, include an eeprom chip IC7, pass through I ²The C bus connects controller IC 6, and the relevant parameter that line control machine is required is stored.IC8 is the UART communication interface of reserving on the line control machine, its 1 pin ground connection, 4 pin are by filter capacitor C12 connection+5V dc source, 2 pin, 3 pin are connected P3.6, the P3.7 pin of described controller IC 6 respectively as data terminal and clock end by resistance R 40, R41, filter capacitor C10, C11, to realize the real-time Transmission of data-signal and clock signal.Described controller IC 6 can communicate with other chips or controller by this telecommunication circuit, and then realizes the effective expansion to the line control machine function.

Fig. 6 is the circuit theory diagrams of a kind of embodiment of display drive circuit, comprises a lcd drive chip IC5.Described lcd drive chip IC5 can adopt a dot matrix liquid crystal driver to realize, its data receiver DATA connects the P3.2 pin of controller IC 6 by resistance R 36, filter capacitor C18, under the control action of the chip selection signal 1621BCS of controller IC 6 output and read-write 1621BWR, receive the data-signal of controller IC 6 outputs, and driving LCDs LCD1 finishes the information demonstration.

Introduce the concrete composition structure and the operation principle of nonpolarity 485 bus circuits below in detail.

Referring to shown in Figure 8, in described nonpolarity 485 bus circuits, comprise two 485 bus chip IC1, IC2.Wherein, in each 485 bus chip IC1 or IC2, all include 1 couple of differential signal end A, B, with differential signal end A, the B of two 485 bus chip IC1, IC2 according to its polarity interconnection, the A end that is about to 485 bus chip IC1 connects the B end of 485 bus chip IC2, the B end of 485 bus chip IC1 is connected the A end of 485 bus chip IC2, and then pass through the corresponding connection of Zener diode ZD1, ZD2 respectively with EBI A1, B1.The data receiver RO of described two 485 bus chip IC1, IC2 connects photoelectrical coupler PC3 by the drive circuit of being made up of triode Q6 and peripheral circuit thereof, carry out the photoelectricity isolation processing of signal through described photoelectrical coupler PC3 after, the data that output serial received signal UART-2-RX connects controller IC 6 receive pin RxD.In like manner, the serial of the data transmitting pin TxD output by controller IC 6 sends signal UART-2-TX, connect photoelectrical coupler PC4 by the drive circuit of forming by triode Q7 and peripheral circuit thereof, and then carry out the photoelectricity isolation processing of signal through described photoelectrical coupler PC4 after, transfer to the data sending terminal DI of two 485 bus chip IC1, IC2.

The duty of described two 485 bus chip IC1, IC2 is controlled by its high-low level state that receives Enable Pin RE and send the received control signal of Enable Pin DE.When receiving the signal that Enable Pin RE receives is high level, and when sending signal that Enable Pin DE receives and being low level, 485 bus chips enter high-impedance state; When receiving the signal that Enable Pin RE receives is low level, and when sending signal that Enable Pin DE receives and being high level, 485 bus chips enter the transmission state; And when reception Enable Pin RE received the low level control signal simultaneously with transmission Enable Pin DE, then 485 bus chips entered accepting state.According to the operating characteristic of 485 bus chip IC1, IC2, can control two 485 bus chip IC1, IC2 by the direct output of 4 road I/O mouths 4 tunnel control signals of controller IC 6 and enter the corresponding work state, with the wiring polarity of coupling external bus.But this design can cause the significant wastage of controller IC 6 pin resources, is unfavorable for the global design of circuit.Based on this, present embodiment has designed a logic circuit again between controller IC 6 and 485 bus chip IC1, IC2, so, 2 road I/O mouths that only need take controller IC 6 are exportable 4 tunnel control signals, to finish the control to two 485 bus chip IC1, IC2.

As shown in Figure 8, described controller IC 6 is by its 2 road I/O mouth P2.4, P2.5 output two-way command signal SI_SELECTA, SI_SELECTB, respectively via triode Q2 and the drive circuit of peripheral circuit composition and drive circuit and the two-way photoelectrical coupler PCI that forms by triode Q4 and peripheral circuit thereof, PC2 is corresponding to be connected, and then by photoelectrical coupler PC1, the light-receiving end of PC2 output two-way after the photoelectricity isolation processing command signal to described logic circuit, after expanding to 4 tunnel control signals, described logic circuit exports described 485 bus chip IC1 to, the reception Enable Pin RE of IC2 and transmission Enable Pin DE are to realize 485 bus chip IC1, the control of IC2 duty.

In the present embodiment, described photoelectrical coupler PC1, PC, PC3, PC4 are used to realize the electrical isolation between controller IC 6 and the 485 bus communication circuit.

In order to improve the antijamming capability of circuit, in the present embodiment, be that 485 bus communication circuit have disposed one tunnel+5V dc source specially, as shown in Figure 8+5V_SI, act on the power end VCC of emitter stage, logic circuit and two 485 bus chip IC1, IC2 of light-receiving end, the triode Q6 of photoelectrical coupler PC1, PC2, PC4 respectively, for it provides operating voltage.

In described logic circuit, mainly comprise one road NPN type triode Q5, six road diode D1～D6 with+pull-up resistor R2～R6 that 5V dc source+5V_SI is connected, its concrete syndeton is referring to shown in Figure 8.Shown in corresponding relation between the level state of the level state of two-way command signal SI_SELECTA, SI_SELECTB by controller IC 6 output and four tunnel control signals of reception Enable Pin RE through exporting two 485 bus chip IC1, IC2 after the logic circuit expansion to and transmission Enable Pin DE sees table.

After line control machine powered on, controller IC 6 acquiescences selected one of them 485 bus chip to carry out data communication, and another chip is placed high-impedance state.Such as: acquiescence selects 485 bus chip IC1 to carry out data communication, and 485 bus chip IC2 are placed high-impedance state.After EBI A1, the B1 of outside 485 buses and line control machine pegged graft, controller IC 6 at first sent 11 command signals, and promptly Shu Chu two-way command signal SI_SELECTA, SI_SELECTB is high level, and then controlled 485 bus chip IC1 reception data.If it is wrong to receive data, such as: the head sign indicating number of the data-signal that receives is not inconsistent with the head sign indicating number of communication protocol defined, perhaps verification is checked incorrect, call peer does not have response etc. also or in official hour, then enable another one 485 bus chip IC2 and carry out data transmit-receive, and control first 485 bus chip IC1 and enter high-impedance state, such as output 00 or 01 command signal.So, outside 485 buses need not to consider wiring polarity when pegging graft, and the controller IC 6 of line control machine inside can be controlled corresponding 485 bus chips automatically according to wiring polarity and enter duty, to realize the coupling of wiring polarity.

Meanwhile, undertaken in the process of data communication by 485 buses at line control machine and external equipment, controller IC 6 is by its I/O mouth P4.0 output low level signal or a series of pulse signal negative electrode to LED 1, the anode of described LED 1 is through resistance R 51 connection+5V dc sources, as shown in Figure 1, and then the 1 luminous or flicker of control LED, to play indicative function.

In the present embodiment, in order to improve the power supply quality of line control machine, the form that adopts on-line controller inside that special power circuit is set to provide working power for each function module circuit of line control machine inside.The concrete structure of described power circuit is referring to shown in Figure 9, be arranged on the special forceful electric power plate, each above-mentioned function module circuit then is arranged on the special light current plate, and plugs by interface CN1, to transmit between the plate of realizing low-voltage dc power supply and control signal.

Described forceful electric power plate is provided with AC power supply jack CN2, receive the external communication civil power, after common mode inductance L01 filters out common mode disturbances, be connected to the rectifying conversion that full bridge rectifier D01～D04 carries out AC-to DC, and then after carrying out step-down and handle via the switching power circuit that transformer T01 and power supply chip IC03 form, by filter circuit output two-way 12V dc source.Wherein, main output 12V is regulated by the adjustable voltage stabilizing a reference source of three ends IC07, to realize accurate pressure control, control use for relay R Y01, RY02, and then after linear voltage-stablizer IC05 voltage stabilizing, provide+the 5V DC voltage exports the light current plate to by 8 pin of interface CN1, uses for controller IC 6 controls; Other one road 12V output voltage can change along with the variation of load, and after linear voltage-stablizer IC06 voltage stabilizing, (promptly+5V_SI) 4 pin by interface CN1 export the light current plate to acquisition+5V DC voltage+M5V, use for 485 bus communications.

In addition, in the line control machine of present embodiment, also include multicircuit relay, such as two-way air-valve relay R Y01, RY02 shown in Figure 9.One end connection+12V dc source of its coil, the

other end

5,6 pin by interface CN1 connect the on-off circuit that is arranged on the light current plate, and through the switch ways ground connection of described on-off circuit.In the present embodiment, described on-off circuit cooperates simple peripheral circuit to be formed by connecting by two-way NPN type triode Q1, Q3, as shown in Figure 7, its base stage connects controller IC 6 two-way I/O mouth P2.2, P2.3 by resistance R 8, R14 respectively, receive the control signal of controller IC 6 outputs, with the on off operating mode of control air-valve relay R Y01, RY02.One of them terminal that the normally opened contact of described air-valve relay R Y01, RY02 is connected the AC power supply jack CN2 of line control machine (is connected the wherein end of common mode inductance L01 in the present embodiment, as shown in Figure 9) and between the fire-wire interfaces CN3 that is provided with on the line control machine, when the controlled closure of air-valve relay R Y01, RY02, be that controller IC 6 is by its P2.2, when the P2.3 mouth is exported the two-way high-level control signal, by fire-wire interfaces CN3 output two-way live wire,, two-way exchanges live wire so that being provided to the air-conditioner blower fan.At this moment, the air-conditioner blower fan only needs to connect zero line by power distribution network, can realize the driving to two blower fans.Adopt this design can make line control machine possess the ability that drives some executing agency, thereby reach the purpose of design that alleviates the host computer burden.

In addition, one road order wire interface CN4 can also be set on line control machine, 1,2 pin by interface CN1 connect 485 order wires on the light current plate, to realize the communication that is connected between line control machine and other external equipments.

Line control machine of the present utility model comes the self adaptation wiring polarity by the design that adopts hardware and software to combine, thereby has greatly made things convenient for the installation and the maintenance of central air conditioner system.

Certainly; the above only is a kind of preferred implementation of the present utility model; should be understood that; for those skilled in the art; under the prerequisite that does not break away from the utility model principle; can also make some improvements and modifications, these improvements and modifications also should be considered as protection domain of the present utility model.

Claims

1, a kind of 485 bus circuits, comprise controller and 485 bus chips, it is characterized in that: described 485 bus chips comprise two, in each 485 bus chip, all include 1 pair of differential signal end, the two paths of differential signals end of two 485 bus chips according to the polarity interconnection after, be connected with EBI; In addition, the duty control end of described two 485 bus chips receives the command signal that described controller sends respectively, and then controls one of them 485 bus chip work according to the grafting situation of external bus.

2,485 bus circuits according to claim 1 is characterized in that: the data sending terminal of described two 485 bus chips is connected the data transmitting pin of described controller with optical coupling isolation circuit by No. one drive circuit; The data of described controller receive pin by other No. one drive circuit and data receiver corresponding be connected of optical coupling isolation circuit with two 485 bus chips.

3,485 bus circuits according to claim 1 and 2 is characterized in that: described controller output two-way command signal generates the output of 4 tunnel control signals through a logic circuit; In each 485 bus chip, its duty control end all includes two-way: the one tunnel receives Enable Pin, and riches all the way send Enable Pin; Corresponding 4 tunnel control signals that receive described logic circuit output of 4 tunnel duty control ends of described two 485 bus chips.

4,485 bus circuits according to claim 3, it is characterized in that: described controller is exported described two-way command signal by its two-way I/O mouth, No. one drive circuit of respectively hanging oneself connects optical coupling isolation circuit, carry out exporting described logic circuit to after photoelectricity is isolated, and then generate 4 tunnel control signals and export two 485 bus chips to, and then control one 485 bus chip and enter high-impedance state, another 485 bus chip enters transmission state or accepting state.

5, a kind of line control machine, comprise controller and 485 bus circuits, it is characterized in that: in described 485 bus circuits, include two 485 bus chips, in each 485 bus chip, all include 1 pair of differential signal end, the two paths of differential signals end of two 485 bus chips according to the polarity interconnection after, be connected with EBI; In addition, the duty control end of described two 485 bus chips receives the command signal that described controller sends respectively, and then controls one of them 485 bus chip work according to the grafting situation of external bus.

6, line control machine according to claim 5 is characterized in that: the data receiver of described two 485 bus chips and data sending terminal are separately by No. one drive circuit and corresponding data pin corresponding be connected of optical coupling isolation circuit with described controller.

7, according to claim 5 or 6 described line control machines, it is characterized in that: described controller output two-way command signal generates the output of 4 tunnel control signals through a logic circuit; In each 485 bus chip, its duty control end all includes two-way: the one tunnel receives Enable Pin, and riches all the way send Enable Pin; Corresponding 4 tunnel control signals that receive described logic circuit output of 4 tunnel duty control ends of described two 485 bus chips.

8, line control machine according to claim 7, it is characterized in that: described controller is exported described two-way command signal by its two-way I/O mouth, No. one drive circuit of respectively hanging oneself connects optical coupling isolation circuit, carry out exporting described logic circuit to after photoelectricity is isolated, and then generate 4 tunnel control signals and export two 485 bus chips to, and then control one 485 bus chip and enter high-impedance state, another 485 bus chip enters transmission state or accepting state.

9, line control machine according to claim 7, it is characterized in that: in described line control machine, also include power circuit, receive the external communication power supply by AC power supply jack, after it was carried out rectification, filtering, step-down and handle, generating the multichannel low-voltage dc power supply was the modular circuit power supply that needs low-voltage DC supply in the line control machine.

10, line control machine according to claim 9, it is characterized in that: in described line control machine, also include multicircuit relay, one end of its coil connects low-voltage dc power supply, the other end is by the switch ways ground connection of on-off circuit, the control end of described on-off circuit receives the control signal of controller output, with the on off operating mode of control relay; The normally opened contact of described relay is connected between the fire-wire interfaces that is provided with on one of them terminal of AC power supply jack of line control machine and the line control machine, and is controlled when closed at relay, provides the interchange live wire to external equipment.