ajax跨域访问报错501的解决方法

$.ajax({      type: "POST",    url: "http://192.168.1.202/sensordata.php",    contentType:'application/json; charset=utf-8',    data: JSON.stringify(ajaxPostData),    dataType:'json',    success: function(data){      //On ajax success do this      console.info("success.");      if (data["status"] == "ok"){        alert("Settings is Ok. The Machine is rebooting.");      }    },    error: function(xhr, ajaxOptions, thrownError) {      //On error do this      console.info("error.");      if (xhr.status == 200) {        alert(ajaxOptions);      }      else {        alert(xhr.status);        alert(thrownError);      }    }  });