CN1547091A - Method and system for data synchronous acquisition/control of information transmitted via GSM - Google Patents

Abstract

The invention is a kind of data synchronous acquisition/control method which uses GSM to transmit information. The character lies in: it uses GPS chip to receive the standard time sent by the GPS system and uses the time as the criterion of information acquisition, uses GSM chip to send the acquired data, time and I/O information to the control centre remotely under control of the microprocessor with mode of short message, correspondently, the control command sent by the GSM chip is received by the GSM short message centre receiving control centre, then uses the microprocessor to send the executing commands. The constructing cost is low, it is stable, safe, high precision, high efficiency, and low transmission cost.

Description

Method and system for data synchronous acquisition/control of information transmitted via GSM

technical field

A method and system for data synchronous acquisition/control of information transmitted through GSM belongs to the field of remote wireless data synchronous acquisition/control of information transmitted through the Global System for Mobile Communications.

Background technique

At present, the automatic monitoring of many water plants (including those with imported equipment) basically copy the Western model. Although a huge automation system is adopted and the investment is large, the adjustment function in some key links is not strong, and the operation costly. These automatic monitoring systems do not fully meet the fundamental purpose of improving the technical and economic benefits of water plants. For many small and medium-sized water plants, the economic conditions are limited. Under the principle of localization and practicality, we should focus on the development of automatic monitoring technology and equipment for those process links that have an important impact on water supply quality and operating costs, and establish a suitable scale of distribution type computer monitoring system. Generally speaking, the water intake is far away from the headquarters of the water purification plant, and the raw water is transported through pipelines. The water intake is usually equipped with several deep well water pumps, and most of the controls involved in the water intake are related to these pumps. The water treatment at the water intake is relatively simple, and there is no need for instruments to monitor the reaction process. Generally, water level gauges, pressure gauges, and flow meters are installed in wells and water pipelines to monitor water delivery. The monitoring system for water source signals becomes a relative Independent signal monitoring system. At present, the existing remote data acquisition/control technical solutions all have many serious defects. Such as: low frequency utilization, resulting in small system capacity, limited signal transmission distance, difficult to achieve wide-area coverage, poor communication stability, heavy maintenance workload, and generally unable to realize simultaneous transmission of voice and environmental status information data and other functions.

GPS (Global Positioning System) global satellite positioning technology: GPS is a radio navigation and positioning system successfully developed by the US Department of Defense for more than 20 years with an investment of 10 billion US dollars. Since the 1990s, the status of GPS in the aerospace field has been recognized. After the technology was opened for civilian use in 1993, it immediately showed a wide range of application prospects. In particular, it has received extensive attention from departments such as public security, finance, insurance, traffic, and transportation. Global Satellite Positioning System (GPS) is a high-precision, all-weather and global radio navigation positioning and timing multifunctional system established with the development of modern science and technology. It uses a satellite network composed of 24 artificial satellites located more than 20,000 kilometers above the earth to continuously transmit positioning signals to the earth. Any GPS receiver on the earth can receive signals from more than four satellites. After calculation, it can report the position (longitude, latitude, altitude), time and motion status (speed, speed, etc.) of the GPS receiver. course). At present, no traditional navigation and positioning technology can achieve the high precision, high speed, all-weather and global performance of GPS.

Global System for Mobile Communications GSM (Global System for Mobile Communications): referred to as GSM, GSM global mobile communication system is currently the digital mobile communication system with the widest coverage, the highest system reliability, and the largest number of telephones in China. GSM provides domestic and international roaming with all telecommunication services to users everywhere in a unified manner. User authentication protects the network from unauthorized users. In addition to providing voice services, the GSM system also provides multiple functions such as data services and short message (SMS) services. The GPS/GSM multifunctional mobile tracking service system uses the SMS short message function to realize data transmission between fixed stations and mobile stations. In the GSM architecture, there is a communication management layer (CM). The function of CM is: to establish connections between users at the request of users, and to maintain and release these calls. SMS is an additional function belonging to the CM layer. The voice or data transmission of the GSM system is established, released and managed according to certain regulations, and SMS is the only service in GSM that does not require the establishment of an end-to-end service path. Simply speaking, the communication channels of the GSM system are divided into voice (or data) channels and control channels, and SMS is realized through the control channel. The basic process of the short message is: there is a short message service center (SMSC) in the GSM system, and the mobile phone sends the short message together with the destination station number to be sent to the SMSC, and then forwards it to another mobile phone designated by the SMSC. The information sent upward by SMS occupies the signaling channel, which occupies a very short time, and SMS does not occupy the voice channel. Sending short messages will not have a great impact on the connection rate of the network, so the communication cost of this method is low. For the positioning monitoring system, not all the monitored vehicles are sending messages non-stop, but the location information is reported regularly, and continuous tracking is only carried out under special circumstances. In this way, the short message service of the GSM network provides a good communication platform for the GPS mobile positioning system. Performance and features of GSM system:

1. Large system capacity. The GSM SMS center can support tens of thousands of users, and under the minimum configuration, it can receive more than 15,000 target information data in one minute;

2. The system has complete functions: In addition to the function of voice call (the mobile phone itself), the system also uses the sending and receiving function of the mobile phone to realize digital short message communication, and completes message transmission functions such as synchronous collection, alarm, service request, and control;

3. Wide range of system services: It can be said that the areas covered by China Mobile's GSM network are all within the scope of system services;

4. High degree of system integration: the system adopts a centralized management method, and the monitoring service center manages the business of the department and other departments; the system facilities are integrated in the customer service center, which is convenient for maintenance, upgrade and management.

5. Low investment in system construction: Since GSM is used as the communication platform, the cost of system construction can be greatly saved;

6. Synchronous monitoring across regions can be realized: If there is no monitoring service center in the local area, but SMS has been opened, the monitoring data can be sent to the monitoring center in other places through the local SMS channel to realize remote synchronous monitoring;

7. Good security and confidentiality: This is reflected in: (a) In the transmission stage, GPS data and commands pass through the GSM signaling channel, which is difficult to monitor. (b) The service center only processes fixed information, and only distributes and stores other data. Therefore, customers can encrypt their own private data according to their needs, and other users cannot obtain it.

GSM (Global System for Mobile communication) is the most mature, perfect and widely used system in the mobile communication system based on time division multiple access technology. In the remote data acquisition/control system, there are a large number of on-site monitoring devices that need to transmit the collected data to the information/control center for processing. These devices are characterized by a large number and wide distribution, and the real-time requirements for data transmission are not very high. However, the cost of each short message sending unit is low, and the system maintenance workload is small. Short message service can be used as the first choice for data communication with the above characteristics. Each data acquisition device is equipped with a short message communication unit and correspondingly equipped with a SIM card. The data acquisition module converts the collected analog quantities into digital quantities, and transmits the data to the baseband part of the communication module through corresponding AT coding processing. The baseband part completes the signal modulation and coding functions, and then transmits the signal to the radio frequency part. The antenna transmits to the GSM network; the GSM network has a special short message processor to store the special short message service, and transmits the short message data to the corresponding data processing center through the telecommunication system.

Present science and technology literature reports relevant based on GSM data acquisition system in large quantities, but is not identical with the present invention, as literature: [1] Li Yede, the remote waterworks groundwater level automatic monitoring system based on GSM short message mode, instrument technology and sensor, 2002 No. 8; [2] Peng Ningkun, Lu Gang, Lu Yimin, Design of GPS Vehicle Monitoring Mobile Unit Based on GSM Short Message, Electronic Engineer, No. 2, 2002; [3] Patent technology name: A GPS (Global Satellite Positioning System ) transmission method of positioning information and control information (patent number: 99125949·1). The system described in document [1] does not have the GPS standard time function of the present invention, if run into GSM short message jam and can't judge the authenticity of long-distance data; The system described in document [2][3] is the vehicle etc. The monitoring of the GPS positioning system transmits GPS positioning information through GSM; the present invention is the synchronous acquisition and monitoring of GPS standard time of a fixed target, and transmits GPS standard time information through GSM. Document [3] also has information such as some voices, images in the vehicle by GSM transmission, what the present invention transmits by GSM is the synchronous collection data that obtains through analog-to-digital conversion, microprocessor has standard communication interface in the present invention, also can Complete remote data collection/control functions through radio stations, infrared rays, etc.

GSM is a digital mobile communication network with the widest coverage, the strongest functions, the strongest anti-interference ability, and the highest communication reliability in my country. GSM short messages are online at any time, without dialing, and cheap. The water source remote monitoring system based on GSM short message is a kind of wireless remote automatic control equipment suitable for small and medium-sized water plants. The invention realizes the problem of remote wireless data collection/control in the GSM short message mode, and provides the system The design and implementation of hardware and software have solved the key technical problems in the process of system implementation.

Description of drawings

Fig. 1 is a schematic diagram of the system composition of the present invention.

Fig. 2 is a schematic diagram of the composition of the device of the present invention.

Figure 3 is a connection diagram of the microprocessor and the GSM chip.

Figure 4 is a connection diagram of the microprocessor and the GPS chip.

Figure 5 is a connection diagram of the microprocessor and the A/D converter.

Fig. 6 is a block flow diagram of the method of the present invention.

Detailed ways

The method of the present invention is shown in FIG. 6 .

This system uses a high-end microprocessor as the controller (33MHz), and uses the analog-to-digital conversion device ADS7864 to perform real-time synchronous acquisition of analog input signals. It is a remote wireless data synchronous acquisition/control device. The system structure diagram of the remote wireless data synchronous acquisition/control device is shown in Figure 1. The microprocessor has two RS232 serial ports, one RS232 port is connected to the GSM module, and the other RS232 port is connected to the GPS module. The microprocessor transmits the data collected synchronously by analog-to-digital conversion and the time information of the GPS (Global Positioning System) global satellite positioning system to the GSM module through an RS232 port, and the GSM module transmits it to the control center through the SMS center. The control center has a personal Composed of computers, it realizes management functions such as saving the data collected remotely and issuing remote control commands, and completes the synchronous collection of remote wireless data; on the contrary, the commands issued by the control center are transmitted to the GSM module through the SMS center, and the GSM module passes through a RS232 The output port is sent to the microprocessor, and the microprocessor issues an execution command through the output port.

The block diagram of the hardware composition of the GSM short message remote wireless data synchronous acquisition/control device is shown in Figure 2. The functions and implementation of each component are introduced below.

The microprocessor core uses a high-speed 8-bit single-chip microprocessor product, which is an improved product of 8051, compatible with the standard 80C52 pin and instruction system, and has 3 compatible timers/counters; 2 serial ports; 4 8-bit I/O ports; on-chip 256B RAM, 1KB SRAM, 16KB ROM; double data pointers. Because the microcontroller has on-chip memory, this system does not need off-chip program/data memory, and the system only expands KB keyboard, LCM liquid crystal display, A/D analog-to-digital converter and GPS module. The two serial ports of the microprocessor are respectively connected to the GPS module and the GSM module.

The acquisition of water level and pressure signals is to convert the water level and pressure data into 4-20mA analog signal through the water level transmitter and pressure transmitter, and then convert the 4-20mA current signal into 0-5V voltage through the interface circuit After the signal, the system can complete the conversion of the analog signal of the water level to the digital signal.

In order to ensure the safe operation of urban water supply and understand the status of wells in water sources, it is necessary to conduct real-time detection and analysis of different wells at the same time. In the past, most of the multi-channel parameters measured by people used one A/D converter shared by multiple analog switches. This not only complicated the circuit and high price, but also it was difficult to avoid the error caused by the sampling aperture time and the influence between devices. Synchronous sampling. The present invention selects the ADS7864 chip for A/D conversion, and the ADS7864 can make the measurement circuit simple, and can ensure the precision and accuracy of the synchronous measurement. In the ADS7864 circuit, the hold signal and the control signal are connected together to ensure simultaneous sampling of 6 signals. For example, when the 5V voltage is required to be converted with 5mV precision, the precision is 5mV/5V=0.1%, that is, 1000 of 1/1000 decimal is required to be 10 bits when expressed in binary, and the resolution of the A/D module used in this system is 12bit. Its accuracy is above ±0.05%, which is sufficient to meet the requirements of the control system. Assuming that the full-scale range of the water level gauge is 20 meters, the signal output by the pressure sensor is amplified by the arithmetic unit and then enters the A/D converter ADS7864. ADS7864 is a 12-bit converter, and the output digital quantity is 0-4095. The resolution of this system is then 0.5 cm and its accuracy is ±0.025%. Fully meet the requirements of water level measurement.

The place where the GSM module is placed is the water source. The GSM module is mainly composed of a radio frequency antenna, internal Flash, GSM baseband processor, matching power supply and a 40-pin ZIP socket. The GSM module interfaces with the microprocessor through a ZIF (Zero Insertion Force) connector (40-pin cable). These 40 pins can be divided into 5 categories, namely power supply, data input/output, SIM card, audio interface and control , the electrical wiring of the microprocessor and the GSM module is shown in Figure 3. The 1st to 14th pins are the power supply part, of which 1 to 5 are the power supply voltage input terminals Vbatt+, which provide a DC power supply with a peak value of 3.3 to 5.5V and 2A; 6 to 10 are the power ground GND; (1 to 5, 6 to 10 power supply circuit , the grounding circuit should be connected in parallel respectively) 11, 12 charging pins, 13 external output voltage (for external circuit use), 14 is the thermistor with negative temperature coefficient connected to ACCU-TEMP. 24~29 are SIM card pins, respectively CC FIN, CC RST, CC IO, CC CLK, CC VCC and CC GND; 33~40 are voice interfaces used to connect to the phone handle. Pins 15, 30, 31 and 32 are the control part, and pin 15 is the ignition wire IGT (Ignition). When TC35 is powered on, IGT must be given a low level greater than 100ms before the module starts. For TC35 module control, IGT signal is very important, only correct IGT signal can make TC35 module run normally. After the system is powered on, in order to make the TC35 enter the working state, a low pulse with a delay of more than 100ms must be added to the IGT, and the duration of the level drop cannot exceed 1ms. After startup, IGT should remain high. When driving IGT, the power supply voltage of TC35 cannot be lower than 3.3V, otherwise it cannot be activated. In order to ensure the correct IGT signal input, the system uses a single-chip microcomputer to drive the TC35 module, and uses software to complete this work. 30 is RTC backup, 31 is power down, and 32 is SYNC. 16-23 bits of data input/output are DSR0, RING0, RXD0, TXD0, CTS0, RTS0, DTR0 and DCD0 respectively.

The present invention is also designed with a GPS module interface, which can simultaneously send GPS time information to the control center through GSM. The GPS module mainly has a 12-pin cable and the MCU interface. The electrical connection between these 12 pins and the MCU MCU system is shown in Figure 4. VIN is the power supply of 3.6VDC-6VDC, GND is the ground of the power supply; PPS is the second pulse output ; TXD1 and RXD1 are standard RS232 interfaces, TXD1 output data (-5VDC-+5VDC), RXD1 input data (-15VDC-+15VDC).

The present invention realizes data remote monitoring under self-developed software. The AT instruction set is jointly developed by Nokia, Ericsson, Motorola and other manufacturers for the GSM system. The GSM module supports the AT instruction set of GSM, including the control of SMS short messages. GSM has two ways to realize the control of SMS, Text Mode and PDU Mode. The present invention sends and receives short messages through the PDU Mode. The flow chart of sending short messages regularly by GSM is shown in Figure 5. Suppose if you need to send the number "23" to the mobile phone number 13041065863, first send the data string AT+CMGS=19<CR>, then wait for the ASCII character ">", and then input the PDU data 00 11 00 0D 91 683140015668F3 00 08 A9 04320033001A. Length 19 does not include the first byte 00 in the PDU data. The TC35 module can return the PDU data to the microcontroller, assuming that the received short message data is "23" and the sender is 13520896603, then the data sent by the TC35 to the microcontroller is <CRLF>08 91 683140015668F3 11 00 0D 91 683125806906F3 00 08 306010613040CR20<CR2 >.

The present invention adopts the existing GSM digital mobile communication network, which avoids the investment in building microwave stations and the maintenance work of microwave stations in the original similar system. It has the characteristics of low construction cost, low maintenance cost, good safety and stability, high data collection accuracy, high data transmission accuracy, high work efficiency, low transmission cost, etc., and multi-channel synchronous data collection, timing data transmission, master station call Data transmission, fault emergency data transmission, six channels of data sharing a short message transmission and other functions. The invention uses GPS to mark time labels on the synchronously collected data, which solves the trouble caused by the blockage of GSM short messages.

The present invention utilizes the existing GSM network resources to give full play to the advantages of high network coverage and good transmission characteristics, and provides a convenient wireless remote data transmission method for the existing synchronous data acquisition/control system, which will become an industrial control and The new development trend in the field of on-site monitoring, not only can be used in the urban water supply industry, but also has a wide range of development space, providing a new idea for wireless remote monitoring systems in other industries such as security, electric power, petroleum, and mining.

Use proves that the method and system for data synchronous acquisition/control of GSM transmission information can achieve the intended purpose, and the test results of the system are as follows:

1. The resolution for synchronous acquisition of 6 analog quantities is 12 bits.

2. The sampling resolution of the analog quantity does not exceed 20 microseconds.

3. The sampling accuracy of the analog quantity is above ±0.05%.

Claims (2)

1. The method of data synchronous acquisition/control when transmitting information through GSM, including the method of transmitting the analog quantity data collected by the microprocessor based on the GSM short message mode of the global mobile communication system, and according to the received GPS information of the global satellite positioning system , it is characterized in that: it is a kind of method that analog quantity data and GPS standard time information are carried out remote synchronous collection/control by GSM short message center by microprocessor, and it contains following steps successively: (1) The microprocessor initializes its own timer by the GPS standard time received by the GPS chip, that is, the global satellite standard clock chip, that is, the sampling start time, the sampling period and the number of sampling times are set; (2) The microprocessor reads the standard sampling time, I/O signal and corresponding sampling data from the analog/digital converter A/D according to the sampling interval and sampling period based on the GPS standard time, and then transmits them through the GSM chip through the GSM chip. The SMS center sends it to the control center wirelessly; (3) The control center transmits the corresponding command to the above-mentioned GSM chip connected to the above-mentioned microprocessor via the GSM short message center, and the above-mentioned microprocessor sends an execution command through the control signal output port according to the control command received from the above-mentioned GSM chip. 2. A system for data synchronous acquisition/control of information transmitted through GSM, which contains a microprocessor, a GSM chip and an interface connected to GPS, and is characterized in that it contains: an 8051 improved high-speed 8-bit single-chip microprocessor arranged at a water source , GSM chip TC35, two RS232 serial interfaces MAX232, GPS chip GARMIN 25LVS, analog/digital conversion chip ADS7864, and water level and pressure transmitters, among them: the second pulse output terminal PPS of the GPS chip and the corresponding signal of the microprocessor The input terminal is connected, the input/output data terminal RXD1/TXD1 of MAX232 is respectively connected with the corresponding terminals 3, 4 and 5, 4 of the microprocessor and the GPS chip, and the power supply terminal VIN and the ground terminal GND of the GPS chip are respectively connected with the corresponding terminals of the microprocessor. The corresponding terminals VCC and VSS are connected, and the reset terminal RESET of the GPS chip is connected with the corresponding terminal of the microprocessor; the TXD and RXD terminals of the other MAX232 are respectively connected with the 19 and 18 terminals of the GSM chip, and its TXDO and RXDO terminals are respectively connected with the microprocessor terminals. The 11,10 ends of the processor are connected, and the IGT end of the GSM chip is connected with the 14 ends of the microprocessor; the GSM chip is also connected with a subscriber identity card SIM, ADS7864 and the corresponding end of the data address of the single-chip microprocessor 87C520WCL connected.

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