2441主机无法向从机写数据

2441主机通过GATT_DiscCharsByUUID（）获取到特性值的handl后，无法对该特性值写数据，返回的状态是error 3，请问是什么原因导致的呢

读写主要使用GATT_WriteCharValue（）和GATT_ReadCharValue().可参考协议栈中例程

    // If procedure complete
    if ( ( pMsg->method == ATT_FIND_BY_TYPE_VALUE_RSP  && 
           pMsg->hdr.status == bleProcedureComplete ) ||
         ( pMsg->method == ATT_ERROR_RSP ) )
    {
      if ( simpleBLESvcStartHdl != 0 )
      {
        // Discover characteristic
        simpleBLEDiscState = BLE_DISC_STATE_CHAR;
        
        req.startHandle = simpleBLESvcStartHdl;
        req.endHandle = simpleBLESvcEndHdl;
        req.type.len = ATT_BT_UUID_SIZE;
        req.type.uuid[0] = LO_UINT16(SIMPLEPROFILE_CHAR1_UUID);
        req.type.uuid[1] = HI_UINT16(SIMPLEPROFILE_CHAR1_UUID);

        GATT_ReadUsingCharUUID( simpleBLEConnHandle, &req, simpleBLETaskId );
      }
    }
  }
  else if ( simpleBLEDiscState == BLE_DISC_STATE_CHAR )
  {
    // Characteristic found, store handle
    if ( pMsg->method == ATT_READ_BY_TYPE_RSP && 
         pMsg->msg.readByTypeRsp.numPairs > 0 )
    {
      simpleBLECharHdl = BUILD_UINT16( pMsg->msg.readByTypeRsp.dataList[0],
                                       pMsg->msg.readByTypeRsp.dataList[1] );
      
      LCD_WRITE_STRING( "Simple Svc Found", HAL_LCD_LINE_1 );
      simpleBLEProcedureInProgress = FALSE;
    }
    
    simpleBLEDiscState = BLE_DISC_STATE_IDLE;

    
  }