free modbus详解.docx

1、free modbus详解freemodbus之协议模块2007-12-27 10:43:32作者：来源：freemodbus之Modbus协议配置浏览次数：844文字大小：【大】【中】【小】简介：Detailed Description详细描述 #include mb.h This module defines the interface for the application. It contains the basic functions and types required to use the Modbus protocol stack. A ty .Detailed Descrip

2、tion详细描述#include mb.h This module defines the interface for the application. It contains the basic functions and types required to use the Modbus protocol stack. A typical application will want to call eMBInit() first. If the device is ready to answer network requests it must then call eMBEnable() t

3、o activate the protocol stack. In the main loop the function eMBPoll() must be called periodically. The time interval between pooling depends on the configured Modbus timeout. If an RTOS is available a separate task should be created and the task should always call the function eMBPoll().这个模块为应用定义了接

4、口。它包括了使用Modbus协议栈所必须的基本功能函数和类型。一个典型的应用程序将会首先调用eMBInit()函数。如果该设备需要回应网络请求，则其必须调用eMBEnable()函数来激活协议栈。在主循环中，函数eMBPoll()将会被周期性调用。两次调用的时间间隔决定于Modbus的超时时间设置。如果使用了RTOS，用户则必须创建一个独立的任务，并且该任务必须一直调用函数eMBPoll()。/ Initialize protocol stack in RTU mode for a slave with address 10 = 0x0A eMBInit( MB_RTU, 0x0A, 3840

5、0, MB_PAR_EVEN ); / Enable the Modbus Protocol Stack. eMBEnable( ); for( ; ) / Call the main polling loop of the Modbus protocol stack. eMBPoll( ); . Defines定义#defineMB_TCP_PORT_USE_DEFAULT0Enumerations枚举类型enum eMBModeMB_RTU,MB_ASCII,MB_TCPModbus协议的模式：RTU，ASCII和TCPenum eMBRegisterModeMB_REG_READ,MB_

6、REG_WRITEModbus寄存器的模式：READ和WRITEenum eMBErrorCodeMB_ENOERR,MB_ENOREG,MB_EINVAL,MB_EPORTERR,MB_ENORES,MB_EIO,MB_EILLSTATE,MB_ETIMEDOUT错误码：没有错误，没有寄存器，无效，IO错误，无效，超时enum eMBParityMB_PAR_NONE,MB_PAR_ODD,MB_PAR_EVENModbus数据帧的校验类型：无校验，偶校验，奇校验Functions函数eMBErrorCodeeMBInit(eMBModeeMode, UCHAR ucSlaveAddress

7、, UCHAR ucPort, ULONG ulBaudRate,eMBParityeParity)协议初始化函数输入参数：eMBModeeMode, Modubus协议模式UCHAR ucSlaveAddress,子模块地址UCHAR ucPort,端口ULONG ulBaudRate,波特率eMBParityeParity串行数据的奇偶校验eMBErrorCodeeMBTCPInit(USHORT usTCPPort)如果使用了TCP协议，则用该函数进行初始化eMBErrorCodeeMBClose(void)关闭Modbus协议栈eMBErrorCodeeMBEnable(void)使能

8、Modbus协议栈eMBErrorCodeeMBDisable(void)禁止Modbus协议栈eMBErrorCodeeMBPoll(void)周期性调用的协议处理函数eMBErrorCodeeMBSetSlaveID(UCHAR ucSlaveID, BOOL xIsRunning, UCHAR const *pucAdditional, USHORT usAdditionalLen)设置子模块ID输入参数：UCHAR ucSlaveID,子模块IDBOOL xIsRunning,UCHAR const *pucAdditional,USHORT usAdditionalLeneMBErr

9、orCodeeMBRegisterCB(UCHAR ucFunctionCode, pxMBFunctionHandler pxHandler)Modbus协议的寄存器回调函数输入参数：UCHAR ucFunctionCode,功能码pxMBFunctionHandler pxHandler功能码对应的处理函数Define Documentation文档#define MB_TCP_PORT_USE_DEFAULT0Use the default Modbus TCP port (502).使用缺省的ModbusTCP移植Examples:MCF5235TCP/demo.c,STR71XTCP

10、/demo.c, andWIN32TCP/demo.cpp.Enumeration Type Documentation枚举类型定义enumeMBErrorCodeErrorcodes used by all function in the protocol stack.在协议栈中所有函数使用的错误码Enumeration values:枚举值MB_ENOERRno error.没有错误MB_ENOREGillegal register address.无效的寄存器地址MB_EINVALillegal argument.无效的参数MB_EPORTERRporting layer error.移

11、植层错误MB_ENORESinsufficient resources.资源不足MB_EIOI/O error. I/O错误MB_EILLSTATEprotocol stack in illegal state.协议栈状态错误MB_ETIMEDOUTtimeout error occurred.超时错误Examples:例子：AT91SAM7X_ROWLEY/demo.c,AVR/demo.c,LINUX/demo.c,MCF5235/demo.c,MCF5235TCP/demo.c,MSP430/demo.c,STR71X/simple2.c,STR71XTCP/demo.c,WIN32/d

12、emo.cpp, andWIN32TCP/demo.cpp.enumeMBModeModbus serial transmission modes (RTU/ASCII).Modubs串行传输模式Modbus serial supports two transmission modes. Either ASCII or RTU. RTU is faster but has more hardware requirements and requires a network with a low jitter. ASCII is slower and more reliable on slower

13、 links (E.g. modems)Modbus串行传输支持两种模式，ASCII或者是RTU。RTU模式较快但是具有较高的硬件要求并且要求网络延迟要低。ASCII模式较慢，但是在低速连接中更加可靠（如moderms）。Enumeration values:MB_RTURTU transmission mode. RTU传输模式MB_ASCIIASCII transmission mode. ASCII传输模式MB_TCPTCP mode. TCP模式enumeMBParityParity used for characters in serial mode.串行模式中字符的极性The pa

14、rity which should be applied to the characters sent over the serial link. Please note that this values are actually passed to the porting layer and therefore not all parity modes might be available.串行字符传输时应用的校验格式。需要注意，这个值其实是传给移植层，并且不是所有的奇偶模式都能有效。Enumeration values:MB_PAR_NONENo parity.无奇偶校验MB_PAR_OD

15、DOdd parity.偶校验MB_PAR_EVENEven parity.奇校验enumeMBRegisterModeIf register should be written or read.寄存器是读还是写This value is passed to the callback functions which support either reading or writing register values. Writing means that the application registers should be updated and reading means that the

16、modbus protocol stack needs to know the current register values.值将传给支持读或者写寄存器的回调函数。写意味着应用寄存器更新，读表示Modbus协议栈需要知道当前寄存器的数值。See also:eMBRegHoldingCB( ),eMBRegCoilsCB( ),eMBRegDiscreteCB( )andeMBRegInputCB( ).Enumeration values:MB_REG_READRead register values and pass to protocol stack.读寄存器数值并且传给协议栈MB_RE

17、G_WRITEUpdate register values.更新寄存器数值Examples:AT91SAM7X_ROWLEY/demo.c,AVR/demo.c,LINUX/demo.c,MCF5235/demo.c,MCF5235TCP/demo.c,MSP430/demo.c,STR71X/simple2.c,STR71XTCP/demo.c,WIN32/demo.cpp, andWIN32TCP/demo.cpp.Function DocumentationeMBErrorCodeeMBClose(void)Release resources used by the protocol s

18、tack.释放协议栈使用的资源。This function disables the Modbus protocol stack and release all hardware resources. It must only be called when the protocol stack is disabled.该函数禁止Modbus协议栈并且释放所有的硬件资源。只有当协议栈被禁止了，才能调用这个函数。Note:注意Note all ports implement this function. A port which wants to get an callback must defi

19、ne the macro MB_PORT_HAS_CLOSE to 1.注意所有的移植都要实现这个函数。需要获取回调Returns:If the resources where released it returneMBErrorCode:MB_ENOERR. If the protocol stack is not in the disabled state it returnseMBErrorCode:MB_EILLSTATE.如果资源释放了，该函数返回eMBErrorCode:MB_ENOERR。如果协议栈不是处于禁止状态，它返回eMBErrorCode:MB_EILLSTATE。Exa

20、mples:LINUX/demo.c,MCF5235TCP/demo.c,STR71XTCP/demo.c,WIN32/demo.cpp, andWIN32TCP/demo.cpp.eMBErrorCodeeMBDisable(void)Disable the Modbus protocol stack.禁止Modbus协议栈。This function disables processing of Modbus frames.这个函数禁止处理Modbus帧。Returns:返回If the protocol stack has been disabled it returnseMBError

21、Code:MB_ENOERR. If it was not in the enabled state it returnseMBErrorCode:MB_EILLSTATE.Examples:LINUX/demo.c,MCF5235TCP/demo.c,STR71XTCP/demo.c,WIN32/demo.cpp, andWIN32TCP/demo.cpp.eMBErrorCodeeMBEnable(void)Enable the Modbus protocol stack.使能Modbus协议栈This function enables processing of Modbus frame

22、s. Enabling the protocol stack is only possible if it is in the disabled state.本函数使能Modbus帧的处理。Returns:If the protocol stack is now in the state enabled it returnseMBErrorCode:MB_ENOERR. If it was not in the disabled state it returneMBErrorCode:MB_EILLSTATE.Examples:AT91SAM7X_ROWLEY/demo.c,AVR/demo.

23、c,LINUX/demo.c,MCF5235/demo.c,MCF5235TCP/demo.c,MSP430/demo.c,STR71X/simple2.c,STR71XTCP/demo.c,WIN32/demo.cpp, andWIN32TCP/demo.cpp.eMBErrorCodeeMBInit(eMBModeeMode,UCHARucSlaveAddress,UCHARucPort,ULONGulBaudRate,eMBParityeParity)Initialize the Modbus protocol stack.初始化Modbus协议栈This functions initi

24、alizes the ASCII or RTU module and calls the init functions of the porting layer to prepare the hardware. Please note that the receiver is still disabled and no Modbus frames are processed untileMBEnable( )has been called.该函数初始化为ASCII或者RTU模式，并且调用移植层的初始化函数来准备硬件。需要注意的是，接受依然是禁止的，并且Modbus数据帧都不会得到处理，除非eM

25、BEnable( )被调用。Parameters:eModeIf ASCII or RTU mode should be used. Modbus模式ucSlaveAddressThe slave address. Only frames sent to this address or to the broadcast address are processed.子模块地址。只有发向本模块地址或者广播地址的数据帧能得到处理。ucPortThe port to use. E.g. 1 for COM1 on windows. This value is platform dependent an

26、d some ports simply choose to ignore it.使用的端口。该值是硬件相关的，许多移植都会选择忽略该参数。ulBaudRateThe baudrate. E.g. 19200. Supported baudrates depend on the porting layer.波特率，所支持的波特率决定于移植层。eParityParity used for serial transmission.串行传输使用的校验。Returns:If no error occurs the function returnseMBErrorCode:MB_ENOERR. The p

27、rotocol is then in the disabled state and ready for activation by callingeMBEnable( ). Otherwise one of the following error codes is returned:eMBErrorCode:MB_EINVALIf the slave address was not valid. Valid slave addresses are in the range 1 - 247.eMBErrorCode:MB_EPORTERRIF the porting layer returned

28、 an error.如果没有错误，这个函数返回eMBErrorCode:MB_ENOERR。协议栈将处于禁止状态，可以通过调用eMBEnable( )来激活。否则，将返回下列的一个错误：eMBErrorCode:MB_EINVAL如果子模块地址无效。eMBErrorCode:MB_EPORTERR如果移植层返回一个错误。Examples:AT91SAM7X_ROWLEY/demo.c,AVR/demo.c,LINUX/demo.c,MCF5235/demo.c,MSP430/demo.c,STR71X/simple2.c, andWIN32/demo.cpp.eMBErrorCodeeMBPo

29、ll(void)The main pooling loop of the Modbus protocol stack.Modbus协议栈的主轮询函数。This function must be called periodically. The timer interval required is given by the application dependent Modbus slave timeout. Internally the function calls xMBPortEventGet() and waits for an event from the receiver or transmitter state machines.该函数必须被周期性调用。两次调用的时间间隔决定于Modbus的超时时间设置。在函数内部调用了xMBPortEventGet()函数来等待接受或者发送状态机发出的事件。Returns:If the protocol stack is not in the enabled state the function returnseMBErrorCode:MB_EILLSTATE. Otherwise it returnseMB