2. 关于mb.c文件的理解
u 宏定义与变量
mb.c文件中定义了一系列的宏定义、函数指针及全局变量,并使用优先编译指令预编译一些程序代码。定义与优先编译部分如下:
#if MB_RTU_ENABLED == 1
#include "mbrtu.h"
#endif
#if MB_ASCII_ENABLED == 1
#include "mbascii.h"
#endif
#if MB_TCP_ENABLED == 1
#include "mbtcp.h"
#endif
#ifndef MB_PORT_HAS_CLOSE
#define MB_PORT_HAS_CLOSE 0
#endif
/* ----------------------- Static variables ---------------------------------*/
static UCHAR ucMBAddress;
static eMBMode eMBCurrentMode;
static enum
{
STATE_ENABLED,
STATE_DISABLED,
STATE_NOT_INITIALIZED
} eMBState = STATE_NOT_INITIALIZED;
/* Functions pointer which are initialized in eMBInit( ). Depending on the
* mode (RTU or ASCII) the are set to the correct implementations.
*/
static peMBFrameSend peMBFrameSendCur;
static pvMBFrameStart pvMBFrameStartCur;
static pvMBFrameStop pvMBFrameStopCur;
static peMBFrameReceive peMBFrameReceiveCur;
static pvMBFrameClose pvMBFrameCloseCur;
/* Callback functions required by the porting layer. They are called when
* an external event has happend which includes a timeout or the reception
* or transmission of a character.
*/
BOOL( *pxMBFrameCBByteReceived ) ( void );
BOOL( *pxMBFrameCBTransmitterEmpty ) ( void );
BOOL( *pxMBPortCBTimerExpired ) ( void );
BOOL( *pxMBFrameCBReceiveFSMCur ) ( void );
BOOL( *pxMBFrameCBTransmitFSMCur ) ( void );
/* An array of Modbus functions handlers which associates Modbus function
* codes with implementing functions.
*/
static xMBFunctionHandler xFuncHandlers[MB_FUNC_HANDLERS_MAX] = {
#if MB_FUNC_OTHER_REP_SLAVEID_ENABLED > 0
{MB_FUNC_OTHER_REPORT_SLAVEID, eMBFuncReportSlaveID},
#endif
#if MB_FUNC_READ_INPUT_ENABLED > 0
{MB_FUNC_READ_INPUT_REGISTER, eMBFuncReadInputRegister},
#endif
#if MB_FUNC_READ_HOLDING_ENABLED > 0
{MB_FUNC_READ_HOLDING_REGISTER, eMBFuncReadHoldingRegister},
#endif
#if MB_FUNC_WRITE_MULTIPLE_HOLDING_ENABLED > 0
{MB_FUNC_WRITE_MULTIPLE_REGISTERS, eMBFuncWriteMultipleHoldingRegister},
#endif
#if MB_FUNC_WRITE_HOLDING_ENABLED > 0
{MB_FUNC_WRITE_REGISTER, eMBFuncWriteHoldingRegister},
#endif
#if MB_FUNC_READWRITE_HOLDING_ENABLED > 0
{MB_FUNC_READWRITE_MULTIPLE_REGISTERS, eMBFuncReadWriteMultipleHoldingRegister},
#endif
#if MB_FUNC_READ_COILS_ENABLED > 0
{MB_FUNC_READ_COILS, eMBFuncReadCoils},
#endif
#if MB_FUNC_WRITE_COIL_ENABLED > 0
{MB_FUNC_WRITE_SINGLE_COIL, eMBFuncWriteCoil},
#endif
#if MB_FUNC_WRITE_MULTIPLE_COILS_ENABLED > 0
{MB_FUNC_WRITE_MULTIPLE_COILS, eMBFuncWriteMultipleCoils},
#endif
#if MB_FUNC_READ_DISCRETE_INPUTS_ENABLED > 0
{MB_FUNC_READ_DISCRETE_INPUTS, eMBFuncReadDiscreteInputs},
#endif
}; |