CN107196707B - Distributed radio over fiber-WiFi-ZigBee network - Google Patents

Abstract

The invention discloses an distributed radio over fiber-WiFi-Zigbee network, which comprises a radio over fiber switching system, a distributed host and a plurality of distributed slaves, wherein the radio over fiber switching system is communicated with the distributed host through a WiFi module, the distributed host is communicated with the distributed slaves through Zigbee wireless modules, the Zigbee wireless communication technology is adopted to effectively cover 50-200 meters, the distributed host is in data communication with the distributed slaves through a Zigbee protocol, the distributed host transmits data to the radio over fiber switching system in steps through WiFi, WiFi access points can be centralized in a control room, so that a multipoint distributed slave can be accessed through WiFi, and the slaves adopt the Zigbee communication technology, namely, each slave does not need to use WiFi for communication, thereby reducing the cost, and in addition, the functions of inquiry and communication according to short addresses of two bytes are realized by adopting the Zigbee protocol, thereby effectively improving the reliability, safety and flexibility of the system, and realizing the acquisition of distributed data.

Description

Distributed wireless over optical-WiFi-ZigBee network

technical field

The invention relates to the technical field of industrial control, in particular to a 2.4GHz-based Zigbee master-slave distributed network in a WiFi optical carrier wireless switching system.

Background technique

The traditional industrial communication method, field bus, has shortcomings such as short transmission distance, poor interoperability, low transmission rate, and manual wiring. Therefore, in order to realize the unattended and remote control of the production site, it has become a trend of technological development to find a convenient and effective way to solve the above problems.

A Chinese invention patent application with publication number CN103200702A discloses a distributed wireless-over-optical-WiFi-Modbus network, including: a wireless-over-optical switching system, a Modbus master and at least two Modbus slaves; the wireless-over-optical switching system Wireless communication is carried out between the system and the Modbus master, and between the Modbus master and the Modbus slave through the radiation antenna; the communication mode between the aforementioned Modbus master and the Modbus slave is wireless communication through the radio frequency signal of the wireless communication module; the optical carrier The wireless switching system includes a central station and an optical link. The optical fiber link connected between the central station and the remote radio frequency unit is used to realize the distribution of WiFi wireless radio frequency signals. The central station is used for signal exchange, control and processing. The radio frequency unit is used to realize photoelectric conversion and radio frequency power amplification. The distributed optical carrier wireless-WiFi-Modbus network proposed in this patent application realizes the wireless collection and centralized management and control of terminal data, and the network environment is flexible, safe and reliable. However, when a certain WiFi-Modbus master fails, a large number of Modbus slaves cannot work, which seriously affects the normal operation of the entire network, and the maintenance and management of the network in the later stage is extremely troublesome.

SUMMARY OF THE INVENTION

In view of the problems existing in the prior art, the purpose of the present invention is to propose a distributed optical-borne wireless-WiFi-Zigbee network with stable and robust network.

To achieve this purpose, the present invention adopts the following technical solutions:

The distributed optical carrier wireless-WiFi-Zigbee network in the present invention is characterized by comprising: an optical carrier wireless switching system, a distributed host, a distributed slave (several), a Zigbee wireless module, and a WiFi module.

The optical carrier wireless switching system combines the optical carrier wireless technology and the WiFi (Wireless Fidelity, wireless fidelity technology) wireless broadband local area network technology, and utilizes the communication between the central station (CS, Central Station) and the remote base station (BS, BaseStation). The optical fiber link realizes the distribution of WiFi wireless radio frequency (RF, Radio Frequency) signals, and the signal exchange, control and processing modules are concentrated in the central station (CS), and the remote base station (BS) only realizes the photoelectric conversion and RF power amplification functions. In this way, the complex and expensive equipment is centralized in the central site, and these equipments are shared by multiple remote base stations, thereby reducing the power consumption and cost of the base station, improving the reliability and security of the system. Dynamic allocation of spectrum bandwidth resources.

The distributed host is composed of a microprocessor, a Zigbee wireless interface, a WiFi network interface, an I/O interface and other hardware and software systems. The distributed host realizes the communication between the host and the optical carrier wireless switching system through the WiFi network interface; the distributed host realizes the control of the distributed slave and the data collection of the distributed slave through the Zigbee wireless interface; the distributed host controls the Zigbee through the I/O interface The wireless module and WiFi module realize wireless data transmission, complete data receiving and sending and status display; the software system includes single-chip control software and application software, the single-chip control system includes the host wireless Zigbee (Z-Stack) protocol, and the application software has host computer sensor data Acquisition system, WiFi module configuration system and other functions.

The distributed slave is composed of a microprocessor, a memory, a Zigbee wireless interface, an I/O interface and other hardware and software systems. The distributed slave realizes the real-time communication between the distributed master and the distributed slave through the Zigbee wireless interface, and completes the commands of the distributed master; the distributed slave controls the Zigbee wireless module through the I/O interface to realize wireless data transmission, and completes the sending and receiving of data. and status display; the software system includes distributed slave wireless Zigbee (Z-Stack) protocol.

The Zigbee wireless module uses 2.4GHz free ISM frequency band license-free, the maximum transmission rate is up to 200Kbps, and the baud rate can be modified by software, the transmission distance in the open field is up to 200 meters, it has functions such as wireless wake-up, the sensitivity is up to -90dBm, and the reliability is up to -90dBm. It can be widely used in the field of short-distance wireless communication in various occasions (such as wireless meter reading, industrial remote control, low-power handheld devices, etc.). The wireless data transmission is realized based on Zigbee wireless module, which improves the reliability.

The WiFi module is a transmission conversion module that converts serial port or TTL level to WIFI communication. The Uart-WiFi module is an embedded module based on the Uart interface that conforms to the WiFi wireless network standard, with built-in wireless network protocol IEEE802.11 protocol stack and TCP /IP protocol stack, which can realize the conversion between user serial port or TTL level data to wireless network. According to the hardware circuit design of the main controller, the mutual conversion between Zigbee and WiFi can be realized, so as to flexibly and conveniently access the distributed optical carrier wireless WiFi network.

Work process description:

Before working, build the required hardware environment, including the construction of the optical wireless system, the construction of the distributed wireless Zigbee master-slave system, and the construction of the terminal acquisition system (temperature and humidity sensor, gas sensor, human body sensor, etc.).

When the system is initialized, the distributed host configures the parameters of each register, WiFi module, Zigbee wireless module, etc., and the distributed slave configures the parameters of each register and Zigbee wireless module. In order to ensure normal communication, it is necessary to set the remote WiFi network of the optical carrier wireless switching system and the WiFi module of the distributed host to have the same SSID (network name), authentication password, working channel, working mode, etc.; The network ID and channel parameters of the Zigbee wireless module of the slave device are the same.

The control center covers the WiFi signal to the remote distributed antenna system through the optical carrier wireless switching system. The WiFi module of the distributed host is connected to the distributed system, and the distributed host is responsible for converting the WiFi signal into Zigbee wireless signal and transmitting it. The center sends the command, and the WiFi module of the distributed host converts it into a Zigbee wireless signal through the optical carrier wireless switching system and sends it to the distributed slave, and the distributed slave sends the command to each through the RS232/RS485 serial interface It is a kind of terminal sensor, which completes the corresponding control and data collection for the sensor. The sensor sends the collected data back to the control center in the same way, so as to achieve high-speed, flexible and safe network coverage, and complete the wireless collection and control of data. and management.

The beneficial effects of the present invention are:

In the existing industrial control network technology, there is no implementation of the distributed optical carrier wireless-WiFi-Zigbee network system of the present invention. The distributed optical carrier wireless-WiFi-Zigbee network technology and concept of the present invention are the first.

The invention is applied in various industrial productions, is economical, convenient, and has good product interoperability, greatly reduces the manual arrangement of communication lines, and well realizes resource sharing and remote centralized monitoring and management. The degree of integration and automation of the domain has positive implications.

In the present invention, the Zigbee wireless communication technology is used to effectively cover 50-200 meters. The distributed host and the distributed slaves communicate with each other through the Zigbee protocol; the distributed host further transmits the data to the optical carrier wireless switching system through WiFi. Since the WiFi access points can be concentrated in the control room, the multi-point distributed slaves can be accessed through WiFi, and the slaves use Zigbee communication technology, that is, each slave does not need to communicate with WiFi, which reduces the cost. The Zigbee protocol is adopted to realize the function of query and communication according to the short address of two bytes, which effectively improves the reliability, security and flexibility of the system, and realizes the collection of distributed data.

Compared with the distributed wireless-over-optical-WiFi-Modbus network, the distributed wireless-over-optical-WiFi-Zigbee network has the function of network auto-healing. In the general distributed optical carrier wireless-WiFi-Zigbee network application, an optical carrier wireless switching system will carry multiple WiFi-Zigbee hosts, and each WiFi-Zigbee host can also carry one or more Zigbee slaves . If a ZigBee slave is in the overlapping network coverage of two WiFi-ZigBee hosts, when one of the WiFi-ZigBee hosts is damaged due to some factor and cannot work normally, the Zigbee slave will automatically connect to the other one. The Zigbee network of the WiFi-Zigbee host does not need to be adjusted and configured manually, which greatly improves the stability and robustness of the network and facilitates the maintenance and management of the network in the later stage.

Description of drawings

Figure 1 is a schematic block diagram of a distributed optical carrier wireless-WiFi-Zigbee network.

Figure 2 is a schematic block diagram of a distributed slave.

Figure 3 is a schematic block diagram of a distributed host.

Fig. 4 The control software flow chart of the distributed wireless-over-optical-WiFi-Zigbee network.

Detailed ways

The present invention is further described below with reference to the accompanying drawings and exemplary embodiments, wherein like numerals in the drawings refer to like parts throughout. Also, if a detailed description of known art is not necessary to illustrate the features of the present invention, it will be omitted.

As shown in Figure 1, a distributed wireless-over-optical-WiFi-Zigbee network includes: a wireless-over-optical switching system 1, a distributed host 2, a distributed slave 3 (several), a Zigbee wireless module, and a WiFi module.

Among them, the optical carrier wireless switching system 1 is a combination of optical carrier wireless technology and WiFi (Wireless Fidelity, wireless fidelity technology) wireless broadband local area network technology, using the central station (CS, Central Station) and the remote base station (BS, BaseStation) between The optical fiber link realizes the distribution of WiFi wireless radio frequency (RF, Radio Frequency) signals, and the signal exchange, control and processing modules are concentrated in the central station (CS), and the remote base station (BS) only realizes photoelectric conversion and RF power amplification. .

The radiation antennas 101 and 201 are radiation antennas of the WiFi module, work in the 2.4GHz frequency band, and transmit and receive WiFi radio frequency signals.

The radiation antennas 211 and 301 are radiation antennas of the ZigBee wireless module, work in the 2.4GHz frequency band, and transmit and receive 2.4G wireless radio frequency signals.

The dotted line indicates that the number of slaves can be 1 to 255.

As shown in FIG. 2 , the distributed slave 3 is composed of a Zigbee module 304 , a microprocessor 303 , an RS232/RS485 module 305 , a power supply module 302 , and an interface 306 , so as to collect external signals through the RS232/RS485 module 305 and the interface 306 . , communicate with the distributed host through the Zigbee module 304, and process the data according to the Z-Stack protocol.

The power module 302 provides power for the distributed slaves, and works at 0.7V-5.5V, 200mA. The solid line 307 is for the power module to provide power to other circuits of the slave. The microprocessor 303 is composed of hardware and software systems such as an internal memory and an I/O interface. The solid bidirectional line 308 is the half-duplex communication line between the microprocessor and the Zigbee wireless module. Zigbee wireless module 304 uses 2.4GHz free ISM frequency band license-free, the maximum transmission rate is up to 200Kbps, and the baud rate can be modified by software, the transmission distance in the open field is up to 200 meters, it has functions such as wireless wake-up, the sensitivity is up to -90dBm, and the transmit power is the largest is 10dBm. The radiating antenna 301 works in the 2.4GHz frequency band, and transmits and receives Zigbee wireless radio frequency signals. The solid bidirectional line 309 is the half-duplex communication line between the microprocessor and the RS232/RS485. The RS232/RS485 module 305 provides conversion for the TTL level of the microprocessor and the external interface RS232/RS485 level. The solid bidirectional line 310 is the half-duplex communication line between the external device and the RS232/RS485. The interface 306 is an RS232/RS485 interface connected with external equipment.

As shown in FIG. 3, the distributed host 2 includes: a WiFi module 205, a Zigbee module 204, a microprocessor 203, and a power supply module 202, which realizes the conversion of WiFi signals and Zigbee signals, and processes the data according to the Z-Stack protocol.

The solid bidirectional line 208 is the half-duplex communication line between the microprocessor and the Zigbee wireless module 204 . Zigbee wireless module 204 uses 2.4GHz free ISM frequency band license-free, the maximum transmission rate is up to 200Kbps, the baud rate can be modified by software, the transmission distance in the open field is up to 200 meters, it has functions such as wireless wake-up, the sensitivity is up to -90dBm, and the transmit power is the largest is 10dBm. The radiating antenna 211 works in the 2.4GHz frequency band, and transmits and receives Zigbee wireless radio frequency signals.

The solid bidirectional line 209 is the half-duplex communication line between the microprocessor and the WiFi module 205 . The WiFi module 205 is a transmission conversion module from serial port or TTL level to WiFi communication. The Uart-WiFi module is an embedded module based on the Uart interface that conforms to the WiFi wireless network standard. It has built-in wireless network protocol IEEE802.11 protocol stack and TCP/ The IP protocol stack can realize the conversion between the user serial port or TTL level data to the wireless network. In the present invention, the WiFi module mainly uses the IEEE802.11 protocol stack to communicate between the optical carrier wireless switching system and the distributed host. The radiating antenna 201 works in the 2.4GHz frequency band, and transmits and receives WiFi wireless radio frequency signals.

The power module 202 provides power for the distributed host, and works at 5.0V-10V, 500mA. The solid line 207 is for the power module to provide power to other circuits of the distributed host. The microprocessor 203 is composed of hardware and software systems such as internal memory and I/O interface.

As shown in Figure 4, when the system initially works, the distributed host configures the parameters of each register, WiFi module, Zigbee wireless module, etc., and the distributed slave configures the parameters of each register, Zigbe wireless module, etc. . In order to ensure normal communication, it is necessary to set the remote WiFi network of the optical carrier wireless switching system and the WiFi module of the distributed host to have the same SSID (network name), authentication password, working channel, working mode, etc.; The network number and channel parameters of the Zigbee wireless module of the slave machine are the same.

The distributed host monitors whether data is sent to the distributed host. If data is received, the data is put into the cache first. If not, it continues to monitor whether the distributed host has received data.

After the distributed host receives the data, it determines whether the data is sent from the optical carrier wireless switching system via WiFi or sent to the distributed host in other ways. If it is sent by the optical carrier wireless switching system, the distributed host parses it according to the custom protocol. The data is automatically sent to the distributed slaves through Zigbee according to the protocol.

If the data received by the distributed host is not the data received from the optical carrier wireless switching system, it will judge whether the data is received from the Zigbee module. If so, then parse the data according to the Z-Stack protocol and pass the data according to the Z-Stack protocol. WiFi is sent to the optical carrier wireless switching system, and then continues to monitor whether the distributed host receives data; if not, continues to monitor whether the distributed host receives data.

If the distributed slave receives Zigbee data, the distributed slave parses the data according to the Z-Stack protocol and processes the data according to the Z-Stack protocol, which can be to read external RS232/RS485 data, etc., and then pass the data through the Zigbee module. Sent to distributed hosts.

Although some exemplary embodiments of the present invention have been shown above, those skilled in the art will appreciate that The scope is defined by the claims and their equivalents.

Claims (2)

1. Distributed optical carrier wireless-WiFi-Zigbee network, is characterized in that, comprises: optical carrier wireless switching system, distributed mainframe and some distributed slaves, between described optical carrier wireless switching system and distributed mainframe through WiFi The module communicates, and the distributed host and the distributed slave communicate through the Zigbee wireless module; The optical carrier wireless switching system includes a central station and a remote base station. The central station and the remote base station are connected by an optical fiber link. The signal exchange, control and processing modules are all concentrated in the central station. The remote base station only realizes photoelectric conversion and RF power amplification function; The distributed host includes: a microprocessor, a Zigbee wireless interface, a WiFi network interface, and an I/O interface. The microprocessor realizes communication between the host and the optical carrier wireless switching system through the WiFi network interface, and the microprocessor realizes the distribution through the Zigbee wireless interface. The control and data collection of the distributed slaves by the host computer; the microprocessor controls the Zigbee wireless module and the WiFi module through the I/O interface to realize wireless data transmission; Described distributed slave includes: microprocessor, memory, Zigbee wireless interface, I/O interface, microprocessor realizes the real-time communication of distributed master and distributed slave through Zigbee wireless interface, completes the command of distributed master , the microprocessor controls the Zigbee wireless module through the I/O interface to realize wireless data transmission, and the microprocessor stores the received or to-be-sent information through the memory In application, an optical carrier wireless switching system carries multiple WiFi-Zigbee hosts, and each WiFi-Zigbee host carries one or more Zigbee slaves; if a ZigBee slave is in two WiFi-Zigbee hosts Within the coverage of the overlapping network, when one of the WiFi-ZigBee hosts is damaged due to some factor and cannot work normally, the Zigbee slave will automatically access the Zigbee network of the other WiFi-Zigbee host. 2 . The distributed wireless-over-optical-WiFi-Zigbee network according to claim 1 , wherein the number of the distributed slaves is 1-255. 3 .

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