With the expansion of the scale of communication networks, the centralized power supply of communication power has gradually shifted to decentralized power supply. On the other hand, from the perspective of reducing staff and increasing efficiency, the Bureau of Communications is required to implement few people and no one's duties.
Under such circumstances, it is necessary to provide secure and reliable power supply for large-scale communications networks and ensure that communications are not interrupted. Therefore, it is necessary to conduct more scientific and standardized management of power supply equipment. The implementation of the remote monitoring system for communication power supplies provides an effective means to achieve the above objectives.
The purpose of the remote monitoring system for communication power supply is to provide real-time monitoring of distributed power supply equipment such as high and low voltage distribution equipment, switching power supplies, and UPS, as well as the power supply, air conditioning and environment of the equipment room in real time. Unable to perform automatic round-the-clock patrols in 24 hours, and automatic alarms are generated. On-duty personnel can check the operation status of the power supply in real time in the monitoring center, thus changing the maintenance of the power supply from a passive, decentralized manual patrol maintenance method to centralized monitoring. , Centralized maintenance, centralized management, reduce maintenance intensity, improve maintenance quality.
1 remote monitoring system program Communication power remote monitoring system is divided into two structures, from the monitoring front (monitoring station) and background (monitoring center), through the PSTN (public telephone switching network) transmission of information. The monitoring front desk has the function of monitoring each communication power supply and each environmental quantity, and transmits the collected data to the background in real time. The monitoring center is a centralized operation and maintenance center for multiple front offices. It consists of monitoring host hardware and monitoring software.
The monitoring center needs to configure two modems, one of which is a real-time Modem, which is used to collect real-time data of the front power supply device, set the operating parameters of the power supply device and perform remote control operations, and the other as an alarm Modem when a controlled end When the board's power supply generates an alarm, if the end office is not currently communicating with the monitoring system through the real-time Moctern, the power monitoring front desk will call the monitoring center's alarm Modem to send the alarm information of the faulty power supply through it to remind the master control. Room operators respond to on-site problems promptly and quickly, minimizing losses. Only one Modem is configured at the monitoring front end of each controlled power supply device to transmit data and alarm information to the monitoring center. When the data volume is not large and the communication data frequency is not high, using a modem and using the telephone line for data transmission is a very reliable method, and the low initial investment cost is also an advantage of this solution.
2 Monitoring Center The monitoring center hardware uses a standard desktop computer and connects to two modems through two serial ports (if the number of serial ports is not enough, it can be extended through a PCI card). The software uses Visual C++ language design and includes functions such as user interface, communication, data processing, display, and file (or database) management. The monitoring software of the monitoring center dials to the front desk of the control office through the real-time Modem. Once Modem dials up successfully, it establishes a dynamic data path from the monitoring center to the remote site monitoring station, which can realize the monitoring center and the monitoring station. Bidirectional data transmission.
3 The digital signal that the Modem communication computer can handle can't enter the analog telephone line directly, must realize the mutual conversion of digital signal to analog signal and analog signal to digital signal through Modem. Modem status can be divided into command status and online status. In addition to dialing for a short time, Modem is always in one of these states. After the modem is powered on, it is in the command state first, and then enters the online state only after the connection is successful.
In the command state, the Modem does not communicate with the remote system, but accepts commands of the DTE device in the form of Hayes standard AT commands. Every time the PC (or MCU) sends an AT command, the Modem returns at least one result code to indicate whether the current execution is correct and the result of the execution. When the communication parties complete the handshake and establish a communication link, the Modem can send and receive data. At this time, the Modem status is called online. In this state, the Modem communicates with the far-end system. At this time, Modem does not attempt to interpret the data sent to him but directly sends it out. When the connection is disconnected, the system first sends a "+++" command to switch the modem from online to command state, and then sends "ATH0" to hang up the modem.
4 Information acquisition content Communication power supply information collection includes three aspects:
(1) Operating parameters such as AC input voltage alarm upper limit, AC input voltage alarm lower limit, ambient temperature alarm upper limit, ambient humidity alarm upper limit, battery temperature alarm upper limit, AC current transformer parameters, system DC output voltage alarm upper limit, system DC output Voltage alarm lower limit, rectifier current limit, rectifier float charge voltage, rectifier charging voltage, rectifier shutdown temperature, rectifier shutdown voltage, battery pack low-voltage alarm threshold, battery pack protection voltage alarm threshold, etc. In addition to these actual operating parameters, the monitoring center can also remotely change (or reset) these parameters.
(2) Real-time data, such as output current of each rectifier, rectifier main radiator temperature, rectifier fan operating status, AC input voltage and current, system DC output voltage and current, and room ambient temperature.
(3) Alarm information, such as rectifier fan failure, high temperature of the main radiator of the rectifier, over-voltage shutdown of the rectifier output, high shutdown of the rectifier temperature; phase loss of the AC input, high AC input voltage, low AC input voltage, and AC power failure , DC output short circuit, DC output abnormality, rectifier 485 communication interruption and so on.
5 Foreground monitoring system hardware design system takes 8031 ​​single-chip microcomputer as the core, man-machine interface adopts LCD display, and has operation keyboard. Watchdog uses ADM706 to improve system reliability. The clock chip uses MC146818 to record the time when real-time data or alarm information is generated. The program memory uses 27C512 EPROM, the limited Chinese character stock used in the system is placed in the high-end address of 27C512, the data memory uses 2 pieces of 62256 SRAM and 1 pieces of 2864E2PROM. The 2864 is an EEPROM and a non-volatile memory, and is used to save the operating parameters of the system. The parameters can be set at the front desk via a keyboard or remotely through a monitoring center. The MAX487 is used to expand a 485 interface for communication with AC distribution cabinets, DC distribution cabinets, rectifier modules, and other environmental equipment. Sensors for data collection are placed in relatively independent smart devices such as AC distribution cabinets, DC distribution cabinets, and rectifiers. Using a programmable universal asynchronous communication interface chip 16C550 and level conversion chip MAX214 extends an RS 232 port used to connect the Modem.
6 front-end monitoring system software design front-end monitoring system software using C51 language design, the main function of the man-machine interface design, 485 communication to obtain the smart device real-time data, power system operating parameter settings, based on Modem-based remote communications to the monitoring center to transmit real-time data And alarm information, the following mainly describes the 16C550 control of the Moctem and remote communication methods.
Programmable universal asynchronous communication interface chip 16C550 has Modem control function, he has 5 interrupt sources, its priority from high to low in order are: receive line status interrupt, receive data ready interrupt, receive data timeout interrupt, send holding register empty interrupt And Modem status interrupt. The 16C550 internal registers used in Modem communication mainly include:
(1) Data receive register (RHR, read-only), address 0x00, register the received character.
(2) The transmit holding register (THR, write only), address 0x00, registers the character to be transmitted.
(3) Interrupt flag register (ISR, read only), address 0x02, used to determine what kind of interrupt is currently generated.
(4) Modem control register (MCR, readable and writable), address 0x04, through this register to achieve the control operation of the Modem.
(5) Communication Line Status Register (LSR, read-only), address 0x05, which provides the CPU with status information related to data transfer.
(6) Modem status register (MSR, read-only), address 0x06, provides Modem operating status.
The dialer module for Modem is as follows:
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After dialing, receive data (or return code) through the 16C550's interrupt service routine. If the Modem is receiving data in the online state, this data is the data transmitted by the monitoring center; if the Modem is in the command state, the data is received by the Modem. Determine the dialing command's reply code during the timer T timing. If the return code ReturnResult is CONNECT, it indicates that the connection is successful (the Modem is online) can send data, otherwise it should hang up the Modem, and the timer T timed to stop and cleared after the redial .
In the above dialing program module, the function of the function Send 16c550Command() is to send an AT command character to the Modem. The contents of the function body are as follows:
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7 Conclusion Based on the communication power remote monitoring system of Modem and public telephone network, the cost of constructing the network is greatly saved. Through practical use, the system is reliable, easy to operate, and can meet the requirements for use. The rapid and real-time information transmission enables the concept of unmanned operation station to be realized. The on-site communication power supply no longer requires on-duty personnel to perform inspections on each device, thus achieving cost-saving, shortening the query time, and providing system operation efficiency.
Under such circumstances, it is necessary to provide secure and reliable power supply for large-scale communications networks and ensure that communications are not interrupted. Therefore, it is necessary to conduct more scientific and standardized management of power supply equipment. The implementation of the remote monitoring system for communication power supplies provides an effective means to achieve the above objectives.
The purpose of the remote monitoring system for communication power supply is to provide real-time monitoring of distributed power supply equipment such as high and low voltage distribution equipment, switching power supplies, and UPS, as well as the power supply, air conditioning and environment of the equipment room in real time. Unable to perform automatic round-the-clock patrols in 24 hours, and automatic alarms are generated. On-duty personnel can check the operation status of the power supply in real time in the monitoring center, thus changing the maintenance of the power supply from a passive, decentralized manual patrol maintenance method to centralized monitoring. , Centralized maintenance, centralized management, reduce maintenance intensity, improve maintenance quality.
1 remote monitoring system program Communication power remote monitoring system is divided into two structures, from the monitoring front (monitoring station) and background (monitoring center), through the PSTN (public telephone switching network) transmission of information. The monitoring front desk has the function of monitoring each communication power supply and each environmental quantity, and transmits the collected data to the background in real time. The monitoring center is a centralized operation and maintenance center for multiple front offices. It consists of monitoring host hardware and monitoring software.
The monitoring center needs to configure two modems, one of which is a real-time Modem, which is used to collect real-time data of the front power supply device, set the operating parameters of the power supply device and perform remote control operations, and the other as an alarm Modem when a controlled end When the board's power supply generates an alarm, if the end office is not currently communicating with the monitoring system through the real-time Moctern, the power monitoring front desk will call the monitoring center's alarm Modem to send the alarm information of the faulty power supply through it to remind the master control. Room operators respond to on-site problems promptly and quickly, minimizing losses. Only one Modem is configured at the monitoring front end of each controlled power supply device to transmit data and alarm information to the monitoring center. When the data volume is not large and the communication data frequency is not high, using a modem and using the telephone line for data transmission is a very reliable method, and the low initial investment cost is also an advantage of this solution.
2 Monitoring Center The monitoring center hardware uses a standard desktop computer and connects to two modems through two serial ports (if the number of serial ports is not enough, it can be extended through a PCI card). The software uses Visual C++ language design and includes functions such as user interface, communication, data processing, display, and file (or database) management. The monitoring software of the monitoring center dials to the front desk of the control office through the real-time Modem. Once Modem dials up successfully, it establishes a dynamic data path from the monitoring center to the remote site monitoring station, which can realize the monitoring center and the monitoring station. Bidirectional data transmission.
3 The digital signal that the Modem communication computer can handle can't enter the analog telephone line directly, must realize the mutual conversion of digital signal to analog signal and analog signal to digital signal through Modem. Modem status can be divided into command status and online status. In addition to dialing for a short time, Modem is always in one of these states. After the modem is powered on, it is in the command state first, and then enters the online state only after the connection is successful.
In the command state, the Modem does not communicate with the remote system, but accepts commands of the DTE device in the form of Hayes standard AT commands. Every time the PC (or MCU) sends an AT command, the Modem returns at least one result code to indicate whether the current execution is correct and the result of the execution. When the communication parties complete the handshake and establish a communication link, the Modem can send and receive data. At this time, the Modem status is called online. In this state, the Modem communicates with the far-end system. At this time, Modem does not attempt to interpret the data sent to him but directly sends it out. When the connection is disconnected, the system first sends a "+++" command to switch the modem from online to command state, and then sends "ATH0" to hang up the modem.
4 Information acquisition content Communication power supply information collection includes three aspects:
(1) Operating parameters such as AC input voltage alarm upper limit, AC input voltage alarm lower limit, ambient temperature alarm upper limit, ambient humidity alarm upper limit, battery temperature alarm upper limit, AC current transformer parameters, system DC output voltage alarm upper limit, system DC output Voltage alarm lower limit, rectifier current limit, rectifier float charge voltage, rectifier charging voltage, rectifier shutdown temperature, rectifier shutdown voltage, battery pack low-voltage alarm threshold, battery pack protection voltage alarm threshold, etc. In addition to these actual operating parameters, the monitoring center can also remotely change (or reset) these parameters.
(2) Real-time data, such as output current of each rectifier, rectifier main radiator temperature, rectifier fan operating status, AC input voltage and current, system DC output voltage and current, and room ambient temperature.
(3) Alarm information, such as rectifier fan failure, high temperature of the main radiator of the rectifier, over-voltage shutdown of the rectifier output, high shutdown of the rectifier temperature; phase loss of the AC input, high AC input voltage, low AC input voltage, and AC power failure , DC output short circuit, DC output abnormality, rectifier 485 communication interruption and so on.
5 Foreground monitoring system hardware design system takes 8031 ​​single-chip microcomputer as the core, man-machine interface adopts LCD display, and has operation keyboard. Watchdog uses ADM706 to improve system reliability. The clock chip uses MC146818 to record the time when real-time data or alarm information is generated. The program memory uses 27C512 EPROM, the limited Chinese character stock used in the system is placed in the high-end address of 27C512, the data memory uses 2 pieces of 62256 SRAM and 1 pieces of 2864E2PROM. The 2864 is an EEPROM and a non-volatile memory, and is used to save the operating parameters of the system. The parameters can be set at the front desk via a keyboard or remotely through a monitoring center. The MAX487 is used to expand a 485 interface for communication with AC distribution cabinets, DC distribution cabinets, rectifier modules, and other environmental equipment. Sensors for data collection are placed in relatively independent smart devices such as AC distribution cabinets, DC distribution cabinets, and rectifiers. Using a programmable universal asynchronous communication interface chip 16C550 and level conversion chip MAX214 extends an RS 232 port used to connect the Modem.
6 front-end monitoring system software design front-end monitoring system software using C51 language design, the main function of the man-machine interface design, 485 communication to obtain the smart device real-time data, power system operating parameter settings, based on Modem-based remote communications to the monitoring center to transmit real-time data And alarm information, the following mainly describes the 16C550 control of the Moctem and remote communication methods.
Programmable universal asynchronous communication interface chip 16C550 has Modem control function, he has 5 interrupt sources, its priority from high to low in order are: receive line status interrupt, receive data ready interrupt, receive data timeout interrupt, send holding register empty interrupt And Modem status interrupt. The 16C550 internal registers used in Modem communication mainly include:
(1) Data receive register (RHR, read-only), address 0x00, register the received character.
(2) The transmit holding register (THR, write only), address 0x00, registers the character to be transmitted.
(3) Interrupt flag register (ISR, read only), address 0x02, used to determine what kind of interrupt is currently generated.
(4) Modem control register (MCR, readable and writable), address 0x04, through this register to achieve the control operation of the Modem.
(5) Communication Line Status Register (LSR, read-only), address 0x05, which provides the CPU with status information related to data transfer.
(6) Modem status register (MSR, read-only), address 0x06, provides Modem operating status.
The dialer module for Modem is as follows:
After dialing, receive data (or return code) through the 16C550's interrupt service routine. If the Modem is receiving data in the online state, this data is the data transmitted by the monitoring center; if the Modem is in the command state, the data is received by the Modem. Determine the dialing command's reply code during the timer T timing. If the return code ReturnResult is CONNECT, it indicates that the connection is successful (the Modem is online) can send data, otherwise it should hang up the Modem, and the timer T timed to stop and cleared after the redial .
In the above dialing program module, the function of the function Send 16c550Command() is to send an AT command character to the Modem. The contents of the function body are as follows:
7 Conclusion Based on the communication power remote monitoring system of Modem and public telephone network, the cost of constructing the network is greatly saved. Through practical use, the system is reliable, easy to operate, and can meet the requirements for use. The rapid and real-time information transmission enables the concept of unmanned operation station to be realized. The on-site communication power supply no longer requires on-duty personnel to perform inspections on each device, thus achieving cost-saving, shortening the query time, and providing system operation efficiency.