CN213238952U

CN213238952U - Photoelectric sensor acquisition system based on two buses

Info

Publication number: CN213238952U
Application number: CN202021869041.1U
Authority: CN
Inventors: 李貌民; 解兆延
Original assignee: Tofe Sensing Technology Shanghai Co Ltd
Current assignee: Tofe Sensing Technology Shanghai Co Ltd
Priority date: 2020-09-01
Filing date: 2020-09-01
Publication date: 2021-05-18
Anticipated expiration: 2030-09-01

Abstract

The utility model discloses a photoelectric sensor acquisition system based on two buses, which comprises a master station and a plurality of slave stations; the master station comprises a master station power supply module, two bus master control modules, a master station singlechip module, an RS485 communication interface, an input/output interface and a storage module; the master station power supply module converts the voltage of an input power supply into 12V, 5V and 3.3V through a DC-DC power conversion chip, and performs power supply isolation through the isolation power supply module to provide a working power supply for the whole master station; the main station singlechip module is the control core of the main station, and receives the instruction sent by the main controller through the RS485 communication interface in real time according to the MODBUS communication protocol. The utility model discloses, remote communication, bus can supply power, and the farthest communication distance can reach 3000 meters, and is high-power. The bus may provide 20A current and a single slave may provide 1A current. And non-polar wiring. The wiring is non-polar, and the installation and debugging time is saved.

Description

Photoelectric sensor acquisition system based on two buses

Technical Field

The utility model relates to a photoelectric sensor technical field specifically is a photoelectric sensor collection system based on two buses.

Background

At present, an RS485 communication interface is mainly adopted in a photoelectric sensor acquisition system adopted in the market. The RS485 is mainly used for communication, has no power supply capacity, and needs to additionally provide two power supply lines to enable the system to normally work, so that an acquisition system based on the RS485 bus generally needs four cables.

In the transmission principle, RS485 adopts a voltage inversion method to transmit signals, and the level inversion method is only used for signal identification, and because no power is transmitted, the signals are easily interfered by other electric fields and magnetic fields. Due to the fact that data are transmitted in a voltage difference mode, alternate change of floating voltage is sampled, and one sending end of the physical layer corresponds to a plurality of high-resistance input modes. Because the receiver is provided with a plurality of high-impedance inputs, although the sending end is provided with push-pull output, a certain interference voltage is coupled into the bus through magnetic coupling at the near end away from the sending end, and the generated voltage can be drained and absorbed by the sending end. But the voltage is very susceptible to interference due to the resistance of the long wire, which is far from the long wire of the transmitter.

In order to solve the problem, terminal equipment generally needs to be added with a terminal matching resistor during RS485 communication, but the disadvantage of the measure is quite obvious: 1. the construction steps and the field debugging time are increased; 2. even with a 100 Ω termination matching resistance, the ability to drain interference is only 0.05 mA. And the power supply noise immunity of dozens of mA real loads at all, which is not an order of magnitude at all; 3. the terminal resistor is added, so that the heating of the RS485 chip at the transmitting end is increased, and the cable driving capability of the RS485 is reduced; 4. if the termination resistance is damaged, the entire bus will fall completely into a breakdown.

In addition, in the aspect of a network topology structure, the RS485 can only adopt a daisy chain connection mode during field construction. However, field construction is often very complicated, the geographical positions of the control ends of the slave stations are relatively disordered, and in addition, the problems of insufficient experience and the like of construction personnel exist, so that the RS485 bus has many disadvantages in field construction.

According to the RS485 standard, shielded twisted pair wires must be used and the wires are individually wired. On the construction site, the wiring is usually random, and the experience and the construction responsibility of the constructors are different. If the floating voltage swing type transmission circuit is wired together with the 220V mains supply, the alternating current 220V generates induction current due to floating voltage swing type signal transmission, the high impedance of the RS485 bus cannot be cleared, and therefore the voltage of the RS485 bus floats and is easily interfered by the on-site 220V alternating current voltage.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a photoelectric sensor collection system based on two buses to solve the problem that proposes among the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme: a photoelectric sensor acquisition system based on two buses comprises a master station and a plurality of slave stations;

the master station comprises a master station power supply module, two bus master control modules, a master station singlechip module, an RS485 communication interface, an input/output interface and a storage module;

the master station power supply module converts the voltage of an input power supply into 12V, 5V and 3.3V through a DC-DC power conversion chip, and performs power supply isolation through the isolation power supply module to provide a working power supply for the whole master station;

the master station singlechip module is a control core of the master station and receives an instruction sent by the master controller through an RS485 communication interface in real time according to an MODBUS communication protocol;

the two bus main control modules; on one hand, the slave station receives an instruction sent by the single chip microcomputer through a serial port, and on the other hand, the slave station data sent by the slave station through the two buses is converted into serial port data and sent to the single chip microcomputer for processing;

the storage module: storing some fixed parameters of the system;

the input and output module comprises two parts: the relay output interface is used for outputting a control signal and controlling the starting and stopping of external equipment; the system main station indicator light is used for representing the working state of the main station and the state of communication data;

the slave station comprises a slave station power supply module, two buses, a slave station singlechip module and a photoelectric sensor input interface;

the slave station power supply module: the functions of overcurrent protection, overvoltage protection, reverse connection prevention protection, rectification and voltage reduction are provided;

the two-bus slave station module: on one hand, receiving an instruction sent by the master station through the two buses, and on the other hand, sending data such as sensor state information to the master station through the two buses;

the photoelectric sensor input interface firstly provides a working power supply for the photoelectric sensor, secondly receives state information of the photoelectric sensor through the optical coupling isolation chip, reads the state information through the slave station single chip microcomputer module, and then sends the state information to the master station through the two buses;

the slave station singlechip module is a control core of the slave station and receives an instruction sent by the master station in real time.

Preferably, the master station power supply module includes a power input protection circuit and a voltage conversion circuit.

Preferably, the storage module adopts an EEPROM storage chip, and the master station singlechip module reads and writes the storage module through an I IC interface to realize data storage and modification.

Preferably, the master station singlechip module comprises a singlechip STM32F042, a crystal oscillator circuit, a reset circuit and a master station debugging interface, wherein the crystal oscillator circuit comprises an element X1 and capacitors C1 and C2; the reset circuit comprises elements R1 and C1, and the master debug interface comprises H1.

Preferably, the two-bus master control module includes a two-bus POWERBUS master control module EV620 and peripheral circuits.

Preferably, the input/output interface comprises a relay output circuit and an indicator light display circuit, and the relay output circuit comprises an optocoupler chip U9, a triode Q5, a relay K1 and an isolation driving power supply U10; the indicator lamp display circuit comprises triodes Q4, Q6 and Q7, and an LED lamp LED5, an LED6 and an LED 7.

Preferably, the RS485 communication interface includes an isolation power module U2, an RS485 isolation chip U15, and an interface protection circuit lamp.

Preferably, the slave station power supply module comprises a self-recovery fuse F1, so that overcurrent protection is realized; the TVS1 is a TVS diode to realize overvoltage protection; d1 is a Schottky diode to realize reverse connection prevention protection; d2 is a rectifier bridge to convert the two bus AC signals into DC voltage; u1 is direct current step-down chip, realizes that the direct current voltage drop is 5V's function, and photoelectric sensor keeps apart power supply circuit, comprises isolation power module U7, electric capacity C8, C9.

Preferably, the slave station singlechip module comprises a singlechip STM8S105, a reset circuit and a slave station debugging interface, wherein the reset circuit comprises elements R25 and C13; the slave station debugging interface comprises H1.

Preferably, the circuit of the photoelectric sensor input interface comprises optical coupling chips U3, U4, U5, U6 and U8 and some peripheral resistance elements and LED indicator light circuits.

Compared with the prior art, the beneficial effects of the utility model are that:

the utility model discloses, remote communication, bus can supply power, and the farthest communication distance can reach 3000 meters, and is high-power. The bus may provide 20A current and a single slave may provide 1A current. And non-polar wiring. The wiring is non-polar, and the installation and debugging time is saved. Any topology. The star-shaped, tree-shaped and bus-type topological structures are supported, and the wiring is more random. The slave station 256 may be hooked. More than 256 nodes can be stably communicated without being influenced by equipment. The wiring is mixed away. The wiring can be mixed with 220V, and a separate pipe is not needed. And the wiring is flexible. And any cable, twisted pair, BV wire and the like are supported. And the cost is saved. And the cost is greatly reduced without electrical isolation. And (3) resisting disturbance. Outstanding interference killing feature, EMC compatibility need not the magnetic ring. Is simple and easy to use. The serial port UART passes through, compatible MODBUS agreement, and the first hand is simple, and is easy and nimble. Low configuration. No requirement on load and no limitation on current fluctuation. Easy expansibility. The relay can flexibly expand the distance, the power and the number of the slave stations.

Drawings

Fig. 1 is a block diagram of the system structure of the present invention;

FIG. 2 is a block diagram of the master station architecture of the system of the present invention;

FIG. 3 is a circuit diagram of the power input protection circuit of the present invention;

FIG. 4 is a circuit diagram of the present invention for converting 24V to 12V;

fig. 5 is a circuit diagram of the present invention for converting 12V to 5V;

fig. 6 is a circuit diagram of the present invention, which is 5V to isolated 3.3V;

fig. 7 is a circuit diagram of a memory module according to the present invention;

FIG. 8 is a circuit diagram of a portion of the master station single chip module of the present invention;

fig. 9 is a circuit diagram of a two-bus master control module according to the present invention;

fig. 10 is a circuit diagram of the output circuit of the relay of the present invention;

FIG. 11 is a circuit diagram of the indicator light of the present invention;

fig. 12 is a circuit diagram of an RS485 communication interface of the present invention;

fig. 13 is a block diagram of a slave station of the system of the present invention;

fig. 14 is a circuit diagram of a slave power supply module and a two-bus slave module according to the present invention;

fig. 15 is a circuit diagram of the isolated power supply of the photoelectric sensor of the present invention;

fig. 16 is a basic circuit diagram of the slave station single chip microcomputer module of the present invention;

fig. 17 is a circuit diagram of a reset and debug interface of the present invention;

fig. 18 is a circuit diagram of the input interface of the photoelectric sensor of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The utility model provides a technical scheme: a photoelectric sensor acquisition system based on two buses is shown in figure 1 and comprises a master station and a plurality of slave stations, wherein the master station mainly comprises a master station power supply module, two bus master control modules, a master station single chip microcomputer module, an RS485 communication interface, an input/output interface and a storage module. A block diagram of the architecture of the primary station of the system is shown in figure 2.

The main station power supply module part changes the input power supply voltage into 12V, 5V and 3.3V through the DC-DC power supply conversion chip, and carries out power supply isolation through the isolation power supply module to provide a working power supply for the whole main station system. The main station single chip microcomputer module is used as a control core of a main station of the whole system, receives an instruction sent by the main controller through the RS485 communication interface according to an MODBUS communication protocol in real time, and completes corresponding tasks such as querying the state of the sensor, setting system parameters and the like. And the two bus control modules receive the instruction sent by the single chip microcomputer through a serial port on one hand, and convert the slave station data sent by the substation through the two buses into serial port data to be sent to the single chip microcomputer for processing on the other hand. The storage module mainly stores some fixed parameters of the whole acquisition system, and the main controller can set and query the parameters through the MODBUS bus. The input and output module mainly comprises two parts: the relay output interface is used for outputting a control signal and controlling the starting and stopping of external equipment; and the system main station indicator light is used for representing the working state of the system main station and the state of the communication data.

The implementation of the parts of the system master station is as follows:

(1) master station power module

The main station power supply module mainly comprises the following parts:

power input protection circuit: as shown in fig. 3, the main functions are overcurrent protection, overvoltage protection and reverse-connection protection. Wherein F3 is a self-recovery fuse to realize overcurrent protection; d7 is a TVS diode to realize overvoltage protection; d6 is a Schottky diode to realize reverse connection prevention protection.

Voltage conversion circuit: as shown in fig. 4, 5, and 6, the main function is voltage conversion. Wherein the function of fig. 4 is that 24V becomes 12V, which is realized by a U4 chip; FIG. 5 is a function of changing 12V into 5V, and is realized by a U7 chip; fig. 6 shows that 5V changes to isolation 3.3V, U13 realizes the function of changing 5V into isolation 5V, and U14 realizes the function of changing isolation 5V into isolation 3.3V.

Memory module

The storage module is shown in fig. 7, the U11 is an EEPROM storage chip, and the single chip microcomputer realizes storage and modification of data through the ii C interface read-write chip U11.

Master station single chip microcomputer module

The master station single-chip microcomputer module is as shown in fig. 8, and the master station single-chip microcomputer module is used as a control core of the whole master station and comprises the following parts: the single chip microcomputer adopts a single chip microcomputer STM32F042 of STM company; the crystal oscillator circuit consists of an element X1 and capacitors C1 and C2; a reset circuit composed of elements R1, C1; and the debugging interface consists of H1.

Two-bus master control module

As shown in fig. 9, the two-bus master control module mainly includes a two-bus POWERBUS master control module EV620 and peripheral circuits.

Input/output interface

The input and output interface part mainly comprises a relay output circuit as shown in figure 10 and an indicator light display circuit as shown in figure 11. The relay output circuit comprises an optocoupler chip U9, a triode Q5, a relay K1, an isolation driving power supply U10 and the like; the indicating lamp circuit consists of triodes Q4, Q6 and Q7, and an LED lamp LED5, an LED6 and an LED 7.

RS485 communication interface

The RS485 communication interface circuit is shown in figure 12. The device mainly comprises an isolation power supply module U2, an RS485 isolation chip U15 and an interface protection circuit lamp.

Slave station

The system slave station mainly comprises a slave station power supply module, a two-bus slave station module, a slave station single chip microcomputer module, a photoelectric sensor input interface and the like. Fig. 13 shows a block diagram of a slave station in the system.

The slave station power supply module obtains a working power supply of the whole slave station through the two-bus POWERBUS, obtains direct-current voltage after rectification and filtering, then changes the direct-current voltage into 5V and 3.3V through the DC-DC power supply conversion chip, and carries out power supply isolation through the isolation power supply module to provide the working power supply for the photoelectric sensor. The slave station single chip microcomputer module is used as a control core of the slave station of the whole system, receives an instruction sent by the master station in real time, and completes corresponding tasks of inquiring the state of the sensor, setting parameters of the slave station and the like. And the two-bus slave station module receives the instruction sent by the master station through the two buses on one hand, and sends data such as sensor state information and the like to the master station through the two buses POWERBUS on the other hand. The photoelectric sensor input interface firstly provides a working power supply for the photoelectric sensor, secondly receives state information of the photoelectric sensor through the optical coupling isolation chip, reads the state information through the slave station single chip microcomputer module, and then sends the state information to the master station through the two buses.

The implementation of the various parts of the system from the station is as follows:

(1) slave station power supply module

Fig. 14 and 15 show the slave power supply module circuit. Fig. 14 is mainly a system power supply circuit, and the main functions are overcurrent protection, overvoltage protection, reverse connection protection, rectification and voltage reduction. Wherein F1 is a self-recovery fuse to realize overcurrent protection; the TVS1 is a TVS diode to realize overvoltage protection; d1 is a Schottky diode to realize reverse connection prevention protection; d2 is a rectifier bridge to convert the two bus AC signals into DC voltage; u1 is the direct current step-down chip, realizes the direct current voltage drop to the function of 5V. Fig. 15 is a schematic diagram of an isolated power supply circuit for a photosensor, which is composed of an isolated power supply module U7, a capacitor C8, a capacitor C9, and the like.

(2) Two-bus slave station module

As shown in fig. 14, the two-bus master control module mainly includes a two-bus POWERBUS slave chip PB331 and a peripheral circuit.

(3) Slave station single chip module

As shown in fig. 16 and 17, the slave one-chip microcomputer module is used as a control core of the whole master station, and includes the following parts: the single chip microcomputer adopts a single chip microcomputer STM8S105 of STM company; a reset circuit composed of elements R25, C13; and the debugging interface consists of H1.

(4) Photoelectric sensor input interface

As shown in fig. 18, the input interface circuit of the photoelectric sensor mainly includes optocoupler chips U3, U4, U5, U6, U8, some peripheral resistive elements, and an LED indicator circuit.

Two buses POWERBUS are adopted to replace an RS485 bus, a master-slave mode structure is adopted, and the whole system consists of a master station and at most 256 slave stations. The main functions of the master station include: 1. providing power to the slave station via the POWERBUS; 2. photoelectric sensor information of the slave station is polled through the POWERBUS bus, an MODBUS bus protocol is adopted, and the photoelectric sensor information is acquired by sending the photoelectric sensor information to main control equipment such as a PLC (programmable logic controller), an industrial personal computer and the like through an RS485 communication interface of the master station. The primary functions of the slave station include: 1. acquiring energy provided by the master station through a POWERBUS bus to enable the slave station to work normally; 2. and receiving the query command sent by the master station through the POWERBUS, and sending the state information of the photoelectric sensor connected with the slave station to the master station. The structure of the whole acquisition system is shown in figure 1

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A photoelectric sensor acquisition system based on two buses is characterized by comprising a master station and a plurality of slave stations;

the storage module: storing some fixed parameters of the system;

the two-bus slave station module: on one hand, receiving an instruction sent by a master station through the two buses, and on the other hand, sending sensor state information data to the master station through the two buses;

2. The two-bus based photosensor acquisition system of claim 1 further comprising: the main station power supply module comprises a power supply input protection circuit and a voltage conversion circuit.

3. The two-bus based photosensor acquisition system of claim 1 further comprising: the storage module adopts an EEPROM storage chip, and the master station singlechip module reads and writes the storage module through an IIC interface to realize data storage and modification.

4. The two-bus based photosensor acquisition system of claim 1 further comprising: the master station singlechip module comprises a singlechip STM32F042, a crystal oscillator circuit, a reset circuit and a master station debugging interface, wherein the crystal oscillator circuit comprises an element X1 and capacitors C1 and C2; the reset circuit comprises elements R1 and C1, and the master debug interface comprises H1.

5. The two-bus based photosensor acquisition system of claim 1 further comprising: the two-bus master control module comprises a two-bus POWERBUS master control module EV620 and peripheral circuits.

6. The two-bus based photosensor acquisition system of claim 1 further comprising: the input and output interface comprises a relay output circuit and an indicator light display circuit, and the relay output circuit comprises an optocoupler chip U9, a triode Q5, a relay K1 and an isolation driving power supply U10; the indicator lamp display circuit comprises triodes Q4, Q6 and Q7, and an LED lamp LED5, an LED6 and an LED 7.

7. The two-bus based photosensor acquisition system of claim 1 further comprising: the RS485 communication interface comprises an isolation power supply module U2, an RS485 isolation chip U15 and an interface protection circuit lamp.

8. The two-bus based photosensor acquisition system of claim 1 further comprising: the slave station power supply module comprises a self-recovery fuse F1, so that overcurrent protection is realized; the TVS1 is a TVS diode to realize overvoltage protection; d1 is a Schottky diode to realize reverse connection prevention protection; d2 is a rectifier bridge to convert the two bus AC signals into DC voltage; u1 is direct current step-down chip, realizes that the direct current voltage drop is 5V's function, and photoelectric sensor keeps apart power supply circuit, comprises isolation power module U7, electric capacity C8, C9.

9. The two-bus based photosensor acquisition system of claim 1 further comprising: the slave station singlechip module comprises a singlechip STM8S105, a reset circuit and a slave station debugging interface, wherein the reset circuit comprises elements R25 and C13; the slave station debugging interface comprises H1.

10. The two-bus based photosensor acquisition system of claim 1 further comprising: the circuit of the photoelectric sensor input interface comprises optical coupling chips U3, U4, U5, U6 and U8, and a plurality of peripheral resistor elements and an LED indicator light circuit.