c++ - freemodbus eMBRegCoilsCB 函数体示例

Question

谁能解释一下如何在 eMBRegCoilsCB()？我正在使用 freemodbus 作为 modbus rtu 从属驱动程序。

我无法添加我的代码，因为它太大了，但您可以在演示中看到示例(下面的链接)。在所有示例中 eMBRegCoilsCB() 未填充。

eMBErrorCode
eMBRegCoilsCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNCoils, eMBRegisterMode eMode )
{
    return MB_ENOREG;
}

eMBErrorCode
eMBRegDiscreteCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNDiscrete )
{
    return MB_ENOREG;
}

编辑

如果尝试写入 (0x15) 偏移量 > 0 的一些位，我的代码将无法正常工作

if ( ( usAddress >= REG_COILS_START )
    && ( usAddress + usNCoils <= REG_COILS_START + REG_COILS_NREGS ) )
{
    iRegIndex = ( int ) ( usAddress - usRegCoilsStart );

    switch ( eMode )
    {
        case MB_REG_READ:
        {
            while ( usNCoils > 0 )
            {
                UCHAR ucResult = xMBUtilGetBits( usRegCoilsBuf, iRegIndex, 1 );

                xMBUtilSetBits( pucRegBuffer, iRegIndex, 1, ucResult );

                iRegIndex++;
                usNCoils--;
            }

            break;
        }

        case MB_REG_WRITE:
        {                
            while ( usNCoils > 0 )
            {
                UCHAR ucResult = xMBUtilGetBits( pucRegBuffer, iRegIndex, 1 );

                xMBUtilSetBits( usRegCoilsBuf, iRegIndex, 1, ucResult );

                iRegIndex++;
                usNCoils--;
            }

            break;
        }
    }
}
else
{
    eStatus = MB_ENOREG;
}

链接

1. freemodbus

Answer 1

试试这个。我做了 REG_COILS_START = 0，以简化地址魔术。但即使在阅读和写作时偏移>0，它也对我有用。

uint8_t modbus_CS[10];
#define TABLE_CS_SIZE ( sizeof(modbus_CS) * sizeof(modbus_CS[0]) )

eMBErrorCode eMBRegCoilsCB(UCHAR * pucRegBuffer, USHORT usAddress,
    USHORT usNCoils, eMBRegisterMode eMode)
{
    usAddress -= 1; /* to c-style address */

    /* check if we away of table size */
    if (usAddress + usNCoils > TABLE_CS_SIZE) {
        return MB_ENOREG;
    }

    switch (eMode)
    {
        case MB_REG_WRITE:
            for (int i = 0; i < usNCoils; i++) {
                UCHAR wbit = xMBUtilGetBits(pucRegBuffer, i, 1 );
                xMBUtilSetBits( modbus_CS, usAddress+i, 1, wbit );
            }
            break;
        case MB_REG_READ:
            for (int i = 0; i < usNCoils; i++) {
                UCHAR rbit = xMBUtilGetBits( modbus_CS, usAddress+i, 1 );
                xMBUtilSetBits( pucRegBuffer, i, 1, rbit );
            }
            break;
    }

    return MB_ENOERR;
}