private int _I2cRead16(byte devAddr, byte[] regAddr, byte length, byte[] data) { int rv; if (i2cMaster.connected == false) { if (_I2cMasterConnect() < 0) { return(-1); } } if (_SetQsfpMode(0x4D) < 0) { return(-1); } rv = i2cMaster.Read16Api(devAddr, regAddr, length, data); if (rv < 0) { MessageBox.Show("QSFP+ module no response!!"); _I2cMasterDisconnect(); } else if (rv != length) { MessageBox.Show("Only read " + rv + " not " + length + " byte Error!!"); } return(rv); }