CN2747584Y - Meter reading module for terminal of electric power load monitoring and managing system - Google Patents
Meter reading module for terminal of electric power load monitoring and managing system Download PDFInfo
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- CN2747584Y CN2747584Y CN 200420082206 CN200420082206U CN2747584Y CN 2747584 Y CN2747584 Y CN 2747584Y CN 200420082206 CN200420082206 CN 200420082206 CN 200420082206 U CN200420082206 U CN 200420082206U CN 2747584 Y CN2747584 Y CN 2747584Y
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Abstract
The utility model relates to a meter reading module for terminal of an electric power load monitoring and managing system, set in the terminal of the electric power load monitoring and managing system and comprising a microprocessor, a local area network interface of the control device, a serial port expanding element circuit, an oscillating circuit connected with the microprocessor, a watch-dog circuit and power circuits connected with each circuit in the meter reading module. The microprocessor is connected with the local area network interfaces of the control device by data wires and control wires and the data and control messages are two-way transmitted; the differential signal terminals of the local area network interface of the control device are connected with the local area network of the control device in the terminal in parallel; the serial port terminal of the microprocessor is two-way connected with the serial port expanding element circuit by data wires and control wires to collect data of the exterior electric energy meter; the meter reading module can carry out the data communication which is of high speed, multi-home, real time and high reliability with the master control board in the terminal by the local area network interfaces of the control device, effectively enhancing the ability and efficiency of collecting electric energy meter data.
Description
Technical field
The utility model relates to the meter-reading module that the electric energy meter data are gathered in electric system, is specifically related to a kind of electric power load monitoring and control management system terminal meter-reading module.
Background technology
See also shown in Figure 1ly, existing meter-reading module is to adopt 485 interfaces to be attempted by on inner 485 buses of electric power load monitoring and control management system terminal the data of externally gathering electric energy meter in the electrical network by meter-reading module.Existing meter-reading module comprises microprocessor MCU, serial port A1, serial port A2, watchdog circuit A3, peripheral control circuit A4,485 interface A5 and connects the interior power supply circuit A6 of each circuit power end in the meter-reading module.
Control bus and data bus in inner each module of meter-reading module all are to be provided by microprocessor MCU, serial ports A1 and serial ports A2 are the interfaces that meter-reading module reads external electric energy table data, and microprocessor MCU data sending terminal is connected with serial ports A1 with the RD1 line by the TD1 line with data receiver; Microprocessor MCU data sending terminal is connected with serial ports A2 with the RD2 line by the TD2 line with data receiver; Serial ports A1 is connected with the external electric energy table by lead with serial ports A2.
Microprocessor MCU is connected with 485 interface A5 by TD line, RD line and 485C line; The differential signal end of 485 interface A5 is attempted by on the cable of 485 buses by signal wire 485A and 485B.
Increased watchdog circuit A3 in order to prevent program unexpected race in operational process from flying, the control signal end of microprocessor MCU is connected with reset line R by control line C3 with the control signal end of watchdog circuit A3, microprocessor MCU is by control line C3, in program operation process, regularly produce pulse, remove the counter of watchdog circuit A3, make watchdog circuit A3 not have reset signal output; If program is because unexpected situation enters an endless loop, and in the time of setting, control line C3 does not produce pulse, and watchdog circuit A3 will export reset signal R, microprocessor MCU resets, and calling program can be re-executed.
Microprocessor MCU is connected with peripheral control circuit A4 with control bus C1 by data bus D1, and peripheral control circuit A4 can receive the data of microprocessor MCU issue or provide state to microprocessor by data bus D1 two-way transfer of data; Microprocessor MCU outputs signal to peripheral control circuit A4 by control bus C1 is unidirectional, controls.
After this terminal receives the order of checking meter of dispatching center, main control module transfers to meter-reading module by 485 interfaces of terminal inner, meter-reading module reads the data of electric energy meter in the electrical network automatically by serial ports A1, serial ports A2, and waits for that the main control module of terminal reads each electric energy meter data in the electrical network by 485 buses.
The electric power load monitoring and control terminal adopts 485 bus termination structures at present, because 485 interfaces adopt the MAX485 chip, this chip internal does not have register, does not have arbitration body yet, though be two-wire system communication, but because intermodule communication speed is lower, communication mode is not supported multi-host communication, and real-time is poor, communication between adjacent two modules can only be transmitted by host node, the time that takies bus is longer, when data traffic is high, can influence data rate; This communication mode support bus arbitration not simultaneously, and the priority of supporting bus intra-network-module not; Also not supporting bus error detection, sending node can't be confirmed the correctness of communicating by letter, if there is a node to be out of order, can make the total system paralysis.
It is host node that a main control module can only be arranged in 485 communication networks, and 485 communication can only initiate and stop by host node, meter-reading module is as then not having this authority from node, therefore, each image data of meter-reading module, can only be after receiving order just can the log-on data capture program, so easy historical data in the equipment running process is lost influences the integrality of data.
Summary of the invention
The purpose of this utility model is to provide a kind of electric power load monitoring and control management system terminal meter-reading module, by connecting controller local area network (CAN) interface, be attempted by on the controller local area network of terminal, make meter-reading module realize with terminal in main control module and each functional module between high speed, lead more, in real time, highly reliable data communication; And can expand the serial ports of a plurality of collection electric energy meter data, can effectively improve ability and efficient that terminal is gathered the electric energy meter data.
The technical solution of the utility model is: a kind of electric power load monitoring and control management system terminal meter-reading module, this module is arranged in the power load management system terminal, and it comprises microprocessor, the oscillatory circuit that is connected with microprocessor, watchdog circuit and the power circuit that is connected with each circuit in the meter-reading module; Be characterized in, also comprise a controller local area network interface, described controller local area network interface is connected with control line and microprocessor are two-way by data line, the differential signal end of controller local area network interface is attempted by on the cable of controller local area network of terminal inner, and microprocessor is by the master control borad two-way transfer of data and the control command of controller local area network interface and terminal; The serial ports end of microprocessor is connected with external electric energy table in the electrical network by lead, gathers external electric energy table data.
Above-mentioned electric power load monitoring and control management system terminal meter-reading module, wherein, described controller local area network interface is made up of controller local area network controller and controller local area network transceiver; Connect clock circuit at the clock signal terminal of controller local area network controller, be connected by received signal line and transmission signal wire between controller local area network controller and the controller local area network transceiver, and two-way transmission received signal and transmission signal; The controller local area network controller is connected with microprocessor with control signal wire by data bus, the differential signal end of controller local area network transceiver is attempted by on the controller local area network of electric power load monitoring and control management system terminal inside, by controller local area network transmitted in both directions differential signal.
Above-mentioned electric power load monitoring and control management system terminal meter-reading module, wherein, described controller local area network interface is made up of microprocessor and controller local area network transceiver; Between microprocessor and the controller local area network transceiver by the received signal line with send signal wire and be connected, and two-way transmission received signal and transmission signal; The differential signal end of controller local area network transceiver is attempted by on the controller local area network of electric power load monitoring and control management system terminal inside, by controller local area network transmitted in both directions differential signal.
Above-mentioned electric power load monitoring and control management system terminal meter-reading module, wherein, also comprise a serial ports expanding element circuit, described serial ports expansion element circuit is connected with microprocessor is two-way by data transmission line, Data Receiving line and control line, and the end of checking meter of serial ports expansion element circuit is connected with the external electric energy table by lead; Microprocessor is gathered the data of outside electric energy meter in the electrical network by the serial ports expansion element circuit.
Above-mentioned electric power load monitoring and control management system terminal meter-reading module, wherein, described serial ports expansion element circuit is made up of serial expanded circuit, serial ports 1, serial ports 2; Serial expanded circuit is by data transmission line and Data Receiving line and 1 two-way connection of serial ports; Serial expanded circuit is by data transmission line and Data Receiving line and 2 two-way connections of serial ports; The end of checking meter of serial ports 1 and serial ports 2 is connected with the external electric energy table respectively by lead.
The utility model electric power load monitoring and control management system terminal meter-reading module owing to adopted above-mentioned technical scheme, makes it compared with prior art, has following advantage and good effect:
Meter-reading module makes to the utlity model has following advantage owing to adopting by the CAN interface and receiving on the controller local area network of terminal:
1, at a high speed, remote message transmission rate, when transfer rate is 1Mbit/S, its transmission range can reach 40m; When transmission range was 10Km, transfer rate still can be up to 5Kbit/S.
2, high total line use ratio, the reception of its CAN message judges that work such as the tissue of CAN frame, transmitting-receiving and verification are finished automatically by CAN controller and transceiver, does not need the microprocessor intervention, has improved the processing speed of data greatly.
3, multi-host communication, meter-reading module can initiatively be initiated communication, and can direct communication between the main control module, improve the reliability of signal exchange.
4, bus arbitration, because the ingenious design of CAN frame structure, bus arbitration carries out automatically according to priority (ID number more little priority is high more), does not need the outer bus arbitration time of occupying volume, bus contention can not take place.
5, monitoring in real time, because CAN single frames message is extremely short, length is 8 bytes, be convenient to handle, so its real-time is very high; Can save the repeating transmission time behind a large amount of bus collisions.
6, simple in circuits, meter-reading module is by the CAN interface and receive on the controller local area network of terminal, only needs two lines to communicate by letter.
7, high anti-interference, this controller local area network adopts the best difference working method of anti-interference, therefore can reach very strong anti-interference, has improved reliability of system operation.
8, meter-reading module can be expanded the serial ports of a plurality of collection electric energy meter data owing to be provided with the serial ports expansion element circuit, can effectively improve ability and efficient that terminal is gathered the electric energy meter data.
Description of drawings
To the description of one embodiment of meter-reading module of a kind of electric power load monitoring and control management system terminal of the utility model, can further understand the purpose of this utility model, specific structural features and advantage by following in conjunction with its accompanying drawing.Wherein, accompanying drawing is:
Fig. 1 is prior art 485 meter-reading module circuit block diagrams.
Fig. 2 is the circuit block diagram of the utility model electric power load monitoring and control management system terminal with meter-reading module.
Fig. 3 is the electric former line of reasoning figure of the utility model electric power load monitoring and control management system terminal with meter-reading module.
Fig. 4 is the CAN interface electrical schematic diagram of the utility model electric power load monitoring and control management system terminal with meter-reading module.
Fig. 5 is the workflow process flow diagram of the utility model with the meter-reading module of controller local area network communication.
Fig. 6 is the overview flow chart of the utility model electric power load monitoring and control management system terminal with the CAN bus of meter-reading module.
Fig. 7 is the CAN bus initialization process flow diagram of the utility model electric power load monitoring and control management system terminal with meter-reading module.
Fig. 8 is the CAN controller transmission message process flow diagram of the utility model electric power load monitoring and control management system terminal with meter-reading module.
Fig. 9 is the CAN controller reception message process flow diagram of the utility model electric power load monitoring and control management system terminal with meter-reading module.
Embodiment
The utility model electric power load monitoring and control management system terminal has adopted controller local area network with meter-reading module, and (English Controller Area Network by name is called for short the CAN bus, this controller local area network comprises the CAN interface and connects the cable of CAN interface) communication mode, make meter-reading module have relative independentability, thereby realize high speed with intermodule, lead more, in real time, anti-interference, highly reliable data communication, the data of user's electric energy meter in the collection network system that can be rapid, correct.
See also shown in Figure 2, the utility model electric power load monitoring and control management system terminal meter-reading module, the serial ports expansion element circuit 2, watchdog circuit D5, oscillatory circuit D11 and the power circuit D8 that comprise microprocessor D1, CAN interface circuit 1, form by serial expanded circuit D4, serial ports 1D6, serial ports 2D7.Microprocessor D1 can adopt 8,16,32 chip microprocessor of any company.Microprocessor D1 is connected with the data terminal of CAN interface 1 by data/address bus AD0 to AD8, the control signal end of microprocessor D1 by chip select line CS, address latch line ALE, read to allow line RD, write allow line WR and interruption permission line INT and reset signal CANRST line respectively with corresponding connection of signal end of CAN interface 1; By microprocessor D1 to CAN interface 1 export chip selection signal CS, address latch signal ALE respectively, read to allow signal RD, written allowance signal WR, reset signal CANRST, CAN interface 1 is to microprocessor D1 output interrupt permission signal INT, and microprocessor D1 is by master control borad two-way transfer of data and the control command of CAN interface 1 with terminal; The differential signal end of CAN interface 1 is attempted by on the cable of controller local area network of terminal inner, and microprocessor D1 is by master control borad two-way transfer of data and the control command of CAN interface 1 with terminal.
Serial ports end at microprocessor D1 connects serial ports expansion element circuit 2, and this serial ports expansion element circuit 2 is made up of serial expanded circuit D4, serial ports 1D6, serial ports 2D7.Microprocessor D1 is connected with the data terminal of serial expanded circuit D4 respectively with Data Receiving line RXD1 by data transmission line TXD1; The chip selection signal end of microprocessor D1 is by being connected with the chip selection signal end of serial expanded circuit D4 respectively with the SEL2 signal wire by the SEL1 signal wire.Serial expanded circuit D4 is connected with the data terminal of serial ports 1D6 respectively with Data Receiving line RXD1 by data transmission line TXD1; Serial expanded circuit D4 is connected with the data terminal of serial ports 2 with Data Receiving line RXD2 by data transmission line TXD2; The bus of the end of checking meter by the external electric energy table W1 in 485A1 line and 485B1 line and the electrical network of serial ports 1D6 is connected; The end of checking meter of serial ports 2D7 is connected by the bus by the external electric energy table W2 in 485A2 line and 485B2 line and the electrical network.The serial ports end of microprocessor D1 is gathered external electric energy table data by serial ports expansion element circuit 2.
Microprocessor D1 is connected with watchdog circuit D5 by reset line RES, control line WDI; Microprocessor D1 is connected with oscillatory circuit D11 by signal wire OSC1, OSC2, by oscillatory circuit D11 to microprocessor D1 clock signal; The output terminal of power circuit D8 is connected with each circuit in this module by the POWER line, and power supply is provided.
See also shown in Figure 3, in the present embodiment, the utility model electric power load monitoring and control management system terminal meter-reading module comprises microprocessor D1 (model is 89C52), the CAN interface circuit of forming by CAN controller D2 (model is SJA1000) and CAN receiver D3 (model is P82C250) 1, by serial expanded circuit D4 (model is CD4052), serial ports 1D6 (model is MAX485), the serial ports expansion element circuit 2 that serial ports 2D7 (model is MAX485) forms, watchdog circuit D5 (model is MAX706), oscillatory circuit D11, oscillatory circuit D21 and power circuit D8.
The signal end 18 of microprocessor D1, signal end 19 are connected with oscillatory circuit D11; This oscillatory circuit D11 by crystal oscillator and crystal oscillator two ends connect capacitor C 1 respectively, C2 constitutes.Oscillatory circuit D11 is to sinusoidal wave clock signal of microprocessor D1 output, and microprocessor D1 is according to the beat work of this clock, and microprocessor D1 sine wave output signal can drive peripherals.
Serial ports expansion element circuit 2 is made up of serial expanded circuit D4, serial ports 1D6, serial ports 2D7; The logical respectively TXD data transmission line of the data sending terminal 11 of microprocessor D1, data receiver 10 and RXD Data Receiving line and serial expanded circuit data terminal 13,3 corresponding connections of data terminal; The end 1 of microprocessor D1 and end are 2 respectively by SEL1 signal wire and the splitting signal end 10 and splitting signal end 9 corresponding are connected of SEL2 signal wire with serial expanded circuit D4; The end 12 of serial expanded circuit D4 and end 1 be the end 4 by TXD1 data transmission line and RXD1 Data Receiving line and serial ports 1D6 and holding for 1 corresponding the connection respectively; The end 14 of serial expanded circuit D4 is distinguished corresponding the connection by TXD2 data transmission line and RXD2 Data Receiving line with end 4 and the end 1 of serial ports 2D6 respectively with end 5; The end 6 of serial ports 1D6 is connected with external electric energy table W1 by 485A1 line, 485B1 line respectively with end 7; The end 6 of serial ports 2D7 is connected with external electric energy table W2 by 485A2 line, 485B2 line respectively with end 7.
When the SEL1 of microprocessor D1 splitting signal end 1 and SEL2 splitting signal end 2 are output as " 0,0 ", choose serial ports 1D6 by serial expanded circuit D4; When the SEL1 of microprocessor D1 splitting signal end 1 and SEL2 splitting signal end 2 are output as " 0,1 ", choose serial ports 2D7 by serial expanded circuit D4; When the SEL1 of microprocessor D1 splitting signal end 1 and SEL2 splitting signal end 2 are output as " 1,0 ", be sky.When the SEL1 of microprocessor D1 splitting signal end 1 and SEL2 splitting signal end 2 are output as " 1,1 ", be sky.
When serial expanded circuit D4 chooses serial ports 1D6, the TXD1 of serial expanded circuit D4 end and RXD1 end conduct communication port at that time, microprocessor D1 communicates by letter by the electric energy meter W1 of serial ports expansion element circuit 2 with the outside.Microprocessor D1 by the data that serial ports 1D6 gathers external electric energy table W1, sends to electric energy meter W1 data by CAN interface 1 master control borad of terminal according to the order of master control borad again.
When serial expanded circuit D4 chooses serial ports 2D7, the TXD2 of serial expanded circuit D4 end and RXD2 end conduct communication port at that time, microprocessor D1 communicates by letter by the electric energy meter W2 of serial ports expansion element circuit 2 with the outside.TXD2 is the data sending terminal of serial expanded circuit D4, and RXD2 is the data receiver of serial expanded circuit D4.Microprocessor D1 by the data that serial ports 2D7 gathers the external electric energy table, sends to the data of electric energy meter W2 by the CAN interface master control borad of terminal according to the order of master control borad again.
In order to prevent that program unexpected race in operational process from flying and having increased watchdog circuit D5 (model is MAX706), the end 6 of microprocessor D1 is connected with the end 6 of watchdog circuit D5, exports the WDI clear signal by microprocessor D1 to watchdog circuit D5; The end 9 of microprocessor D1 is connected with the end 7 of watchdog circuit D5, exports the RESET reset signal by watchdog circuit D5 to microprocessor D1; Microprocessor D1 regularly produces pulse by control line WDI in program operation process, remove the counter of watchdog circuit D5, makes watchdog circuit D5 not have reset signal RESET output; If program is because unexpected situation enters an endless loop, in the time of setting, control line WDI does not produce pulse, and watchdog circuit D5 will export reset signal RESET, microprocessor D1 reset (RESET) calling program can be re-executed.The power supply of watchdog circuit D5 is provided by " VCC " and " GND " line by power circuit.
Please cooperate referring to Fig. 3, Fig. 4, CAN interface 1 is made up of CAN controller D2 (model is SJA1000) and CAN transceiver D3 (model is P82C250), realizes the control and the transmitting-receiving of CAN interface.Between the clock signal terminal 9 of CAN controller D2, end 10, connect clock circuit, this clock circuit by crystal oscillator and crystal oscillator two ends connect capacitor C 3 respectively, C4 constitutes; The end 13 of CAN controller D2 is connected with the end 1 of CAN transceiver D3, sends data TX0 by CAN controller D2 to CAN transceiver D3; The end 19 of CAN controller D2 is connected with the end 4 of CAN transceiver D3, by CAN transceiver D3 output data RX0 to CAN controller D2.
Other has a kind of CAN interface (circuit diagram is not provided), and controller is integrated in the microprocessor, and this CAN interface is made up of microprocessor and CAN transceiver; Between microprocessor and the CAN transceiver by the received signal line with send signal wire and be connected, and two-way transmission received signal and transmission signal; The differential signal end of CAN transceiver is attempted by on the cable of controller local area network of electric power load monitoring and control management system terminal inside, by controller local area network transmitted in both directions differential signal.
Please continue referring to shown in Figure 3, in the present embodiment, the end 39 of microprocessor D1 to end 32 is connected by data/address bus AD0 to AD8 between end 28 with end 1, end 2, the end 23 of CAN controller D2, and two-way transmission phase data-signal; The end 5 of microprocessor D1, end 30, end 17, end 16, end 13, end 7 by chip select line CS, address latch line ALE, read to allow line RD, write allow line WR and interrupt allowing line INT and reset signal CANRST line respectively with end 4, end 3, end 5, end 6, end 16,17 corresponding connections of end of CAN controller D2; By microprocessor D1 to CAN controller D2 export chip selection signal CS, address latch signal ALE respectively, read to allow signal RD, written allowance signal WR, reset signal CANRST.Export interrupt permission signal INT by CAN controller D2 to microprocessor D1; The differential signal CANL of CAN transceiver end 6, differential signal CANH end 7 are attempted by on the cable of controller local area network of electric power load monitoring and control management system terminal, by controller local area network transmitted in both directions differential signal CANH and CANL.The output terminal of power circuit is connected with the power end of CAN controller D2, and power supply is provided.
The structure of CAN interface 1 is comparatively simple, if for safety, can use the isolation bus, only needs to add suitable buffer circuit and gets final product.After CAN controller D2 sent or received a frame message, CAN controller D2 can produce an INT look-at-me and export to microprocessor D1, and microprocessor D1 carries out interrupt handling routine.CAN controller D2 gives CAN transceiver D3 by TX0 line output data; Transceiver D3 sends CAN controller D2 to after by RX0 line received signal.The differential signal output port CANH of CAN transceiver D3 and CANL are by CAN bus transmitted in both directions sub-signal.After microprocessor D1 writes a frame information, write again send to allow order after, CAN controller D2 sends this frame information immediately; Have no progeny when CAN controller D2 produces in a reception, microprocessor D1 reads the content of the reception buffer of CAN controller D2.
The form of the CAN Frame of CAN interface 1 has two kinds, and a kind of CAN standard frame must have the identifier of 11 bit bytes at the 2.0A of CAN agreement version regulation CAN controller; Another kind of CAN expansion frame can have the identifier of 11 or 29 bytes at the 2.0B of CAN agreement version regulation CAN controller.
Below be the standard frame chart of the utility model electric power load monitoring and control management system terminal with the CAN bus of meter-reading module.
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| Byte 1 | FF | RTR | X | X | DLC (data length) | |||
| Byte 2 | (message identification code) ID.10-ID.3 | |||||||
| Byte 3 | ID.2-ID.0 | X | X | X | X | X | ||
| Byte 4 | Data 1 | |||||||
| | Data 2 | |||||||
| Byte 6 | Data 3 | |||||||
| Byte 7 | Data 4 | |||||||
| Byte 8 | | |||||||
| Byte 9 | Data 6 | |||||||
| Byte 10 | Data 7 | |||||||
| Byte 11 | Data 8 | |||||||
CAN standard frame information is 11 bytes, comprises two parts: information and data division.Preceding 3 bytes are message part.Byte 1 is a frame information.The 7th (FF) represents frame format, in standard frame, and FF=0; The type of the 6th (RTR) expression frame, RTR=0 is expressed as Frame, and RTR=1 is expressed as remote frame; The data length of reality when DLC is illustrated in Frame.Byte 2,3 is the message identification code, and 11 effectively.Byte 4～11 is the real data of Frame, and is invalid during remote frame.
Below be the expansion frame chart of the utility model electric power load monitoring and control management system terminal with the CAN bus of meter-reading module.
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| Byte 1 | FF | RTR | X | X | DLC (data length) | |||
| Byte 2 | (message identification code) ID.28-ID.21 | |||||||
| Byte 3 | ID.20-ID.13 | |||||||
| Byte 4 | ID.12-ID.5 | |||||||
| | ID.4-ID.0 | X?X?X | ||||||
| Byte 6 | Data 1 | |||||||
| Byte 7 | Data 2 | |||||||
| Byte 8 | Data 3 | |||||||
| Byte 9 | Data 4 | |||||||
| Byte 10 | | |||||||
| Byte 11 | Data 6 | |||||||
| Byte 12 | Data 7 | |||||||
| Byte 13 | Data 8 | |||||||
The CAN Extended Superframe Format is that the identifier length of CAN can reach 29.In the present embodiment, CAN controller D2 supports the CAN2.0B agreement, promptly supports the extended format message structure of 29 bit identifiers.CAN expansion frame information is 13 bytes, comprises two parts, information and data division.Preceding 5 bytes are message part.Byte 1 is a frame information.The 7th (FF) represents frame format, in the expansion frame, and FF=1; The type of the 6th (RTR) expression frame, RTR=0 is expressed as Frame, and RTR=1 is expressed as remote frame; Real data length when DLC is illustrated in Frame.Byte 2～5 is the message identification code, its high 29 effectively.Byte 6～13 is the real data of Frame, and is invalid during remote frame.
The arbitration mechanism of CAN bus, CSMA/CD is the abbreviation of " Carrier Sense Multiple Access/collision detection " (CarrierSense Multiple Access with Collision Detect).When having two nodes to send simultaneously on the bus, must by " harmless arbitration by turn " method make highest priority message preferentially send.Each the bar message that sends on the CAN bus all has unique one 11 or the ID of 29 bit digital.The CAN bus state depends on binary number ' 0 ' rather than ' 1 ', thus ID number more little, then this message has high more right of priority.Therefore message for complete ' 0 ' identifier has the highest right of priority on the bus.Both in the position of message collision, first node sends 0 and other node sends 1, sends the control that 0 node will be obtained bus so, and the information that sends out it that can success.Utilize the CSMA access bus, can detect, have only when bus is in idle condition, just allow to send signal on the bus.Utilize this method, meter-reading module is by the CAN interface and receive on the CAN bus, can with the direct and two-way transmission information of the master control borad of terminal.
The CAN transmission line can use multiple physical medium, for example twisted-pair feeder, optical fiber etc.What adopt in the present embodiment is twisted-pair feeder, and signal uses differential voltage to transmit, and two signal line are called as " CAN_H " and " CAN_L ", all are about 2.5V when static, and this moment, state representation was a logical one, also can be called " recessiveness ".Than the high presentation logic of CAN_L " 0 ", be called " dominance " with CAN_H, at this moment, magnitude of voltage is usually: CAN_H=3.5V and CAN_L=1.5V.
The utility model meter-reading module is by the CAN interface and receive on the controller local area network of terminal, has at a high speed, remote message transmission rate: when transfer rate is 1Mbit/S, its transmission range can reach 40m; When transmission range was 10Km, transfer rate still can be up to 5Kbit/S; The reception of its message judges that work such as the tissue of frame, transmitting-receiving and verification are finished automatically by CAN controller and transceiver, does not need microprocessor to get involved, and has improved the exchange rate of data greatly, and has improved total line use ratio; Meter-reading module can initiatively be initiated communication, can become host node in the section sometime, realizes multi-host communication; Bus arbitration carries out automatically according to priority (ID number more little priority is high more), can save the repeating transmission time behind a large amount of bus collisions; Because of CAN single frames message length is 8 bytes, be convenient to handle; Simple in circuits adopts the difference working method, reaches very strong anti-interference; When a node detection during to irrecoverable property mistake, its controller can make this node withdraw from bus activity (this point is very important) automatically, does not influence the proper communication of other node, has improved reliability of system operation.
The output terminal output dc voltage of power circuit provides power supply by other circuit in the POWER alignment module.
A kind of electric power load monitoring and control management system terminal of the utility model with the circuit theory of meter-reading module is, after the terminal opening power, after meter-reading module is finished initialization, microprocessor D1 orders by " read data " that the CAN interface sends according to the master control borad of terminal, when microprocessor D1 chose serial ports 1D6 by serial expanded circuit D4, microprocessor D1 communicated by letter by the electric energy meter W1 of serial ports expansion element circuit 2 with the outside; Microprocessor D1 by the data that serial ports 1D6 gathers external electric energy table W1, sends to the data of electric energy meter W1 by the CAN interface master control borad of terminal according to the order of master control borad again.When microprocessor D1 chose serial ports 2D7 by serial expanded circuit D4, microprocessor D1 communicated by letter by the electric energy meter W2 of serial ports expansion element circuit 2 with the outside; Microprocessor D1 by the data that serial ports 2D7 gathers the external electric energy table, sends to the data of electric energy meter W2 by the CAN interface master control borad of terminal according to the order of master control borad again.
See also shown in Figure 5, the utility model electric power load monitoring and control management system terminal with the workflow of meter-reading module is, meter-reading module is after the terminal opening power, beginning meter-reading module initialize routine, after initialization was finished, meter-reading module began to wait for that master control borad passes through the CAN interface and sends order " the CAN interface receives message ".If not order, meter-reading module is waited for the master control borad order always; If master control borad sends order, what meter-reading module analysis master control borad needed now is the data of " serial ports 1 " or " serial ports 2 "; After analysis is finished, meter-reading module is gathered external electric energy table data from serial ports 1 or serial ports 2 respectively, promptly " read external electric energy table W1 data " or " reading external electric energy table W2 data ", receive the transmission message commands of master control borad again, meter-reading module carries out the transmission of message by the CAN bus, is the meter-reading module query message sent completely? be sent completely if do not finish then wait until always,, then return and receive " CAN receives message " again if be sent completely.
Please cooperate referring to shown in Figure 6, the CAN software overall procedure of meter-reading module is by reset processing, the hardware configuration of CAN controller, CAN initialization of register, the transmission CAN message of CAN controller D2 in the utility model, and the handling procedure that receives CAN message and message is formed.
Please cooperate referring to shown in Figure 7, it is the initialization flowchart of CAN controller D2, CAN controller D2 removes the reset mode request flag and enters before the mode of operation, must whether be eliminated really by first checkmark, whether entered mode of operation, just can carry out next step operation, this reads to indicate and realizes that this circulation is constantly to attempt clear flag whether successfully to leave reset mode with checking by circulation.
Please cooperate referring to shown in Figure 8, the transmission of message is independently finished by the CAN controller D2 of meter-reading module, and the message information that microprocessor D1 must will send is write transmission buffer, then with the transmission request flag set in the command register.When sending message, transmission buffer is write locking, meter-reading module sends the data of gathering the external electric energy table to master control borad, the transmission result that can send the mode confirmation message of successful zone bit by inquiry by interrupt request or the master routine of CAN controller D2 after finishing.
Please cooperate referring to shown in Figure 9, when meter-reading module receives the order of master control borad, independently finish the reception of message by CAN controller D2, the message that CAN controller D2 receives is placed on reception buffer, the CAN controller receives under this type of receipt and interrupts forbidden energy (here with the mode of inquiring about), microprocessor D1 often reads the status register of CAN controller D2, checks to receive buffer status sign RBS, sees whether receive a message; Microprocessor D1 continues current task, and up to receiving the new request of checking the reception buffer state, the reception buffer Status Flag is represented completely to that is to say and received one or more messages.After CAN controller D2 obtained first message from reception, the corresponding positions by the set command register sent one and discharges the reception buffer order, littlely went out to manage device D1 before checking the more information message, can handle the message that each is received.
In sum, the utility model with the meter-reading module of controller local area network communication by the CAN interface and receive on the controller local area network of terminal, by the CAN bus can and terminal in main control module and each and functional module between at a high speed, lead more, in real time, anti-interference, highly reliable data communication; Meter-reading module can be expanded the serial ports of a plurality of collection electric energy meter data owing to be provided with the serial ports expansion element circuit, can effectively improve ability and efficient that terminal is gathered the electric energy meter data, thereby improves the correctness of terminal monitoring, guarantees that electrical network normally moves.
Claims (5)
1, a kind of electric power load monitoring and control management system terminal meter-reading module, this module is arranged in the power load management system terminal, and it comprises microprocessor, the oscillatory circuit that is connected with microprocessor, watchdog circuit and the power circuit that is connected with each circuit in the meter-reading module; It is characterized in that: also comprise a controller local area network interface, described controller local area network interface is connected with control line and microprocessor are two-way by data line, the differential signal end of controller local area network interface is attempted by on the cable of controller local area network of terminal inner, and microprocessor is by the master control borad two-way transfer of data and the control command of controller local area network interface and terminal; The serial ports end of microprocessor is connected with external electric energy table in the electrical network by lead, gathers external electric energy table data.
2, electric power load monitoring and control management system terminal meter-reading module according to claim 1, it is characterized in that: described controller local area network interface is made up of controller local area network controller and controller local area network transceiver; Connect clock circuit at the clock signal terminal of controller local area network controller, be connected by received signal line and transmission signal wire between controller local area network controller and the controller local area network transceiver, and two-way transmission received signal and transmission signal; The controller local area network controller is connected with microprocessor with control signal wire by data bus, the differential signal end of controller local area network transceiver is attempted by on the controller local area network of electric power load monitoring and control management system terminal inside, by controller local area network transmitted in both directions differential signal.
3, electric power load monitoring and control management system terminal meter-reading module according to claim 1, it is characterized in that: described controller local area network interface is made up of microprocessor and controller local area network transceiver; Between microprocessor and the controller local area network transceiver by the received signal line with send signal wire and be connected, and two-way transmission received signal and transmission signal; The differential signal end of controller local area network transceiver is attempted by on the controller local area network of electric power load monitoring and control management system terminal inside, by controller local area network transmitted in both directions differential signal.
4, electric power load monitoring and control management system terminal meter-reading module according to claim 1, it is characterized in that: also comprise a serial ports expanding element circuit, described serial ports expansion element circuit is connected with microprocessor is two-way by data transmission line, Data Receiving line and control line, and the end of checking meter of serial ports expansion element circuit is connected with the external electric energy table by lead; Microprocessor is gathered the data of outside electric energy meter in the electrical network by the serial ports expansion element circuit.
5, electric power load monitoring and control management system terminal meter-reading module according to claim 4, it is characterized in that: described serial ports expansion element circuit is made up of serial expanded circuit, serial ports 1, serial ports 2; Serial expanded circuit is by data transmission line and Data Receiving line and 1 two-way connection of serial ports; Serial expanded circuit is by data transmission line and Data Receiving line and 2 two-way connections of serial ports; The end of checking meter of serial ports 1 and serial ports 2 is connected with the external electric energy table respectively by lead.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200420082206 CN2747584Y (en) | 2004-08-25 | 2004-08-25 | Meter reading module for terminal of electric power load monitoring and managing system |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200420082206 CN2747584Y (en) | 2004-08-25 | 2004-08-25 | Meter reading module for terminal of electric power load monitoring and managing system |
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| CN2747584Y true CN2747584Y (en) | 2005-12-21 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN 200420082206 Expired - Fee Related CN2747584Y (en) | 2004-08-25 | 2004-08-25 | Meter reading module for terminal of electric power load monitoring and managing system |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104237839A (en) * | 2014-09-12 | 2014-12-24 | 国家电网公司 | Standard electric energy high-frequency impulse high-fidelity transmission system |
| CN106468734A (en) * | 2015-08-19 | 2017-03-01 | Ls 产电株式会社 | Electricity monitoring system |
| CN110865955A (en) * | 2019-11-19 | 2020-03-06 | 天津津航计算技术研究所 | High-reliability merging and forwarding system for multi-path full-duplex serial port |
-
2004
- 2004-08-25 CN CN 200420082206 patent/CN2747584Y/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104237839A (en) * | 2014-09-12 | 2014-12-24 | 国家电网公司 | Standard electric energy high-frequency impulse high-fidelity transmission system |
| CN106468734A (en) * | 2015-08-19 | 2017-03-01 | Ls 产电株式会社 | Electricity monitoring system |
| CN110865955A (en) * | 2019-11-19 | 2020-03-06 | 天津津航计算技术研究所 | High-reliability merging and forwarding system for multi-path full-duplex serial port |
| CN110865955B (en) * | 2019-11-19 | 2023-03-10 | 天津津航计算技术研究所 | High-reliability merging and forwarding system of multi-path full-duplex serial port |
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Granted publication date: 20051221 Termination date: 20120825 |