CN201266434Y

CN201266434Y - Isolation type bus power supply communication system

Info

Publication number: CN201266434Y
Application number: CNU2008201658935U
Authority: CN
Inventors: 吴建德; 杨波; 李武华; 何湘宁
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2008-10-14
Filing date: 2008-10-14
Publication date: 2009-07-01
Anticipated expiration: 2018-10-14

Abstract

The utility model discloses an isolation-typed bus power supply communication system, comprising a power supply module which is connected on a power supply/communication bus, and N communication modules, wherein, N is at least 2; the power supply module comprises a power switch circuit and a switch control circuit; the communication module comprises an isolation transformer, a rectifier and stabilizer circuit, a data sending circuit, a data receiving circuit and a communication control circuit; the transmission of each data bit of the communication module on the power supply/communication bus comprises 4 stages as follows: a positive power supply stage, a negative power supply stage, a magnetic recovery stage and a data communication stage. The bus power supply communication system has simple circuit structure, realizes the functions of power supply and data signal transmission on one pair of transmission bus simultaneously, realizes signal isolation by single transformer, greatly simplifies the complexity of the circuit, reduces the cost, and supports master-slave communication and peer-to-peer communication when forming a multi-node bus communication mode.

Description

Isolation type bus supplying communication system

Technical field

The utility model relates to a kind of isolation type bus supplying communication system, especially by the unibus transmission power supply of transformer isolation transmission and the system of data, belongs to the field bus communication technical field.

Background technology

In fields such as Industry Control, intelligent building, monitoring of toolss, the demand that exists the check point that in a large number scene disperseed and reference mark to be connected by bus.Bussing technique commonly used at present has RS485, CAN, ProfiBus etc.Compare with centralized star-like line, bus mode can significantly reduce the total length of line and the complexity of wiring.The interface of each bus module needs a pair of power lead and a pair of signal wire.

Consider that in order further to reduce line and slave unit intrinsic safety characteristic the technology of multiple need by a pair of line while transmission signals and power supply also arranged at present, as IEC1158-2 standard that ProfiBus-PA adopted etc.This technology adopts Manchester's cde that base-band data signal is added on the power lead, transmits again.

ProfiBus-PA is used widely at industrial control field.But ProfiBus-PA is the same with RS485, CAN, all has a shortcoming: bus and communication controler are not isolated, and when current potential between a plurality of controlled volumes does not wait, must the additional isolation circuit be isolated by the communication data line and the bus of communication controler.By the DC/DC buffer circuit that controller power source and bus is isolated in addition, thereby need a large amount of peripheral circuits.

Summary of the invention

The purpose of this utility model provides a kind of simple in structure, can realize the isolation type bus supplying communication system of power supply supply and data transmission on a pair of power supply/communication bus simultaneously.

Isolation type bus supplying communication system of the present utility model is characterized in that comprising power module and N communication module of being connected on power supply/communication bus, and N is at least 2, wherein:

Power module comprises power switch circuit and ON-OFF control circuit, and the input end of power switch circuit links to each other with power supply, output termination power/communication bus, and ON-OFF control circuit links to each other with power switch circuit;

Communication module comprises isolating transformer, regulator rectifier circuit, data transmit circuit, data receiver circuit and communication control circuit, the former limit winding of isolating transformer links to each other with power supply/communication bus, the secondary winding of isolating transformer respectively with the input end of regulator rectifier circuit, the input end of data receiver circuit and the output terminal of data transmit circuit link to each other, the input end of data transmit circuit links to each other with the data sending terminal of communication control circuit, the output terminal of data receiver circuit links to each other with the data receiver of communication control circuit, and the output terminal of regulator rectifier circuit is to data transmit circuit, data receiver circuit and communication control circuit provide power supply; The transmission of each data bit of communication module on power supply/communication bus all comprises 4 stages: positive supply stage, negative supply stage, magnetic reset stage and data communication phase.

The transmission course of a position signal of native system comprises 4 stages: positive supply stage, negative supply stage, magnetic reset stage and data communication phase.In the positive supply stage, power module output positive voltage; In the negative supply stage, on power supply/communication bus negative voltage, this negative voltage can be exported by power module, also can be produced automatically by the former limit exciting curent of the isolating transformer of communication module.In the magnetic reset stage, power module turn-offs output, and the data transmit circuit of communication module is output voltage not also, reverts to zero with the exciting curent that guarantees isolating transformer in this stage.In data communication phase, power module turn-offs output, and when communication module sent data " 0 ", the data transmit circuit output voltage through the isolating transformer coupling, produced a potential pulse, expression " logical zero " on power supply/communication bus.In data communication phase, data receiver circuit detects input voltage, when it is worth greater than fixed threshold Vref, judges that bus is " logical zero ", otherwise is " logical one ".

Native system by defining corresponding frame format, just can be realized the intercommunication mutually between communication node on the basis of realizing the position transmission.

Bus supplying communication system circuit structure of the present utility model is simple, realizes the function of power supply supply and data signal transmission on a pair of transfer bus simultaneously, and realizes Signal Spacing by single transformer, has simplified the complexity of circuit greatly and has reduced cost.When constituting multinode bus communication mode, support master-slave communication and peer-to-peer communications.

Description of drawings

Fig. 1 is the formation block diagram of isolation type bus supplying communication system;

Fig. 2 is the formation block diagram of communication module;

Fig. 3 is a kind of practical circuit of concrete power module;

Fig. 4 is a kind of practical circuit of concrete communication module;

Fig. 5 is the sequential chart of transmission one digit number certificate on the bus.

Specific implementation method

Further specify the utility model below in conjunction with accompanying drawing

With reference to Fig. 1, Fig. 2, isolation type bus supplying communication system of the present utility model comprises power module 1 and N communication module 2 of being connected on power supply/communication bus, N is at least 2, wherein:

Power module 1 comprises power switch circuit 3 and ON-OFF control circuit 4, and the input end of power switch circuit 3 links to each other with power supply, output termination power/communication bus, and ON-OFF control circuit 4 links to each other with power switch circuit 3;

Communication module 2 comprises isolating transformer 5, regulator rectifier circuit 6, data transmit circuit 7, data receiver circuit 8 and communication control circuit 9, the former limit winding of isolating transformer 5 links to each other with power supply/communication bus, the secondary winding of isolating transformer 5 respectively with the input end of regulator rectifier circuit 6, the output terminal of the input end of data receiver circuit 8 and data transmit circuit 7 links to each other, the input end of data transmit circuit 7 links to each other with the data sending terminal of communication control circuit 9, the output terminal of data receiver circuit 8 links to each other with the data receiver of communication control circuit 9, and the output terminal of regulator rectifier circuit 6 is to data transmit circuit 7, data receiver circuit 8 and communication control circuit 9 provide power supply.

Fig. 3 is a kind of practical circuit of concrete power module, power switch circuit 3 is the full bridge inverter of being made up of power MOS pipe T1, T2, T3, T4 in this example, ON-OFF control circuit 4 is made up of the driver U1 of microcontroller U2 and power MOS pipe, here the driver U1 of power MOS pipe adopts chip I R2110, and the control gate pole of the power MOS pipe of full bridge inverter links to each other with the output terminal of chip I R2110.Full bridge inverter, half-bridge inversion circuit, forward converter, double tube positive exciting circuit, push-pull circuit, circuit of reversed excitation or resonance inversion circuit that power switch circuit 3 also can adopt other power devices to form.

Fig. 4 is a kind of practical circuit of concrete communication module, here, regulator rectifier circuit 6 is by diode D1, D2, D3, D4, the full-wave rectification mu balanced circuit that capacitor C 1, C2 and voltage stabilizing chip U3 form, regulator rectifier circuit or also can adopt half-wave rectifier voltage circuit.Regulator rectifier circuit 6 is given data transmit circuit 7, data receiver circuit 8 and communication control circuit 9 power supplies.Data transmit circuit 7 is made up of triode T5, T6, T7, T8 and driving circuit U4, and the output terminal of driving circuit U4 links to each other with the base stage of triode T5, T6, T7, T8, and triode T5, T6, T7, T8 can adopt MOSFET to replace here.Data receiver circuit 8 is by divider resistance R1, R2, the single-ended comparator circuit that comparer U5 and reference voltage source Vref form, the output of reference voltage source Vref links to each other with the negative terminal of comparer U5, and the output after resistance R 1, the R2 dividing potential drop links to each other with the anode of comparer U5; Data receiver circuit 8 or also can adopt the difference comparator circuit.Communication control circuit 9 is realized for microprocessor MCU programming in this example, perhaps also can be realized by CPLD/FPGA chip or other hardware circuits.

Fig. 5 is the sequential chart of transmission one digit number certificate on the bus.Its transmission course comprises 4 stages: positive supply stage T1, negative supply stage T2, magnetic reset stage T3 and data communication phase T4.

During system works, after external dc power was input to the power switch circuit 3 of power module 1, through the regulating action of ON-OFF control circuit 4, output waveform as shown in Figure 5.At time period T1, the power switch circuit 3 output positive voltages of power module 1 give all communication modules 2 power supplies.At time period T2, the power switch circuit 3 of power module 1 produces negative voltage, the purpose that produces negative pressure is that the bus average voltage in time period T1 and the T2 is close to zero, prevent that the isolating transformer 5 in the communication module 2 from producing the dc magnetization effect, also can give communication module 2 power supplies at T2 time period internal power on-off circuit 3.At time period T3 and T4, the power switch circuit 3 of power module 1 is output power not.The magnetization current of isolating transformer 5 resets fully in time period T3.At time period T4, carry out the data transmission of a position between N communication module 2, its transmission principle is as follows: data receiver circuit 8 becomes the logic level signal that digital circuit can be discerned with the output voltage of isolating transformer 5, is input to communication control circuit 9.Communication control circuit 9 in the time period, according to the level situation of data receiver, can judge that bus state is " logical zero " or " logical one " at T4.When communication module 2 sends data 0, present electric energy by isolating transformer 5 to bus in T4 time period inner control data transmit circuit 7, make bus be in " logical zero " state, thereby realize sending data procedures.

Claims

1. isolation type bus supplying communication system is characterized in that comprising the power module (1) and N the communication module (2) that are connected on power supply/communication bus, and N is at least 2, wherein:

Power module (1) comprises power switch circuit (3) and ON-OFF control circuit (4), and the input end of power switch circuit (3) links to each other with power supply, output termination power/communication bus, and ON-OFF control circuit (4) links to each other with power switch circuit (3);

Communication module (2) comprises isolating transformer (5), regulator rectifier circuit (6), data transmit circuit (7), data receiver circuit (8) and communication control circuit (9), the former limit winding of isolating transformer (5) links to each other with power supply/communication bus, the secondary winding of isolating transformer (5) respectively with the input end of regulator rectifier circuit (6), the output terminal of the input end of data receiver circuit (8) and data transmit circuit (7) links to each other, the input end of data transmit circuit (7) links to each other with the data sending terminal of communication control circuit (9), the output terminal of data receiver circuit (8) links to each other with the data receiver of communication control circuit (9), and the output terminal of regulator rectifier circuit (6) is to data transmit circuit (7), data receiver circuit (8) and communication control circuit (9) provide power supply; The transmission of each data bit of communication module (2) on power supply/communication bus all comprises 4 stages: positive supply stage, negative supply stage, magnetic reset stage and data communication phase.

2. isolation type bus supplying communication system according to claim 1 is characterized in that the power switch circuit (3) of power module (1) is full bridge inverter, half-bridge inversion circuit, forward converter, double tube positive exciting circuit, push-pull circuit, circuit of reversed excitation or resonance inversion circuit.

3. isolation type bus supplying communication system according to claim 1, the regulator rectifier circuit (6) that it is characterized in that communication module (2) is full-wave rectification mu balanced circuit or half-wave rectifier voltage circuit.