modbus问题!发送RTU串下位机不响应?
向下位机发送控制串,预置单个寄存器
串如下:
UINT pwriteBuffer[8];
pwriteBuffer[0]=0x1;
pwriteBuffer[1]=0x6; //功能码
pwriteBuffer[2]=0x0;
pwriteBuffer[3]=0x4; //寄存器地址
pwriteBuffer[4]=0xff; //高位数据
pwriteBuffer[5]=0xff; //低位数据
m_crcByte = 0xffff;
crcHandle(pwriteBuffer[0]);
crcHandle(pwriteBuffer[1]);
crcHandle(pwriteBuffer[2]);
crcHandle(pwriteBuffer[3]);
crcHandle(pwriteBuffer[4]);
crcHandle(pwriteBuffer[5]);
pwriteBuffer[6]=m_crcByte&0xff; //crc高位
pwriteBuffer[7]=m_crcByte/0x100; //crc低位
bWriteStat = WriteFile(m_hCom,pwriteBuffer,
8,&dwBytesWrite,NULL);
下位机不响应这命令,我用modbus调试精灵有能够响应,不知道是否串格式有误,请各位赐教!