setTimeout(function() {

    //监控报表

var MonitorWidget = 'a1';

//目标报表

var ValueWidget = 'a1';

//监控单元格

var MonitorCellSite = 'A3';

//报表块背景设置

//未选中背景

var bg_unchecked_JSON = {"background" : "url(/webroot/help/picture/ceshi/weixuanzhong.png)no-repeat",

                            "background-size" : "100% 100%"};

//选中背景

var bg_checked_JSON = {"background" : "url(/webroot/help/picture/ceshi/xuanzhong.png)no-repeat",

                            "background-size" : "100% 100%"};

//获取监控报表块对象

var Monitor = _g().getWidgetByName(MonitorWidget);

//获取对应的刷新报表块对象

var Refresh = _g().getWidgetByName(ValueWidget);

//获取目前对应刷新报表块的当前值，并将其赋值给oldNum

var newNum = Monitor.getCellValue(MonitorCellSite);

var oldNum = newNum; 

//初始值赋予展示的刷新报表块

if(oldNum * 1 != 0 &&  oldNum.length != 0 ) {

Refresh.setCellValue("A3", oldNum);

Refresh.css(bg_unchecked_JSON);

}

//

var global_timer = setInterval(function() {

newNum = Monitor.getCellValue(MonitorCellSite); //获取最新数据

if (newNum != oldNum && newNum * 1 != 0 && newNum.length != 0) {

//判断新值与旧值不同，设置背景变化

Refresh.css(bg_checked_JSON);

oldNum = newNum;

Refresh.setCellValue("A3", oldNum);

//一定时间后刷新回原来背景1500ms

setTimeout(() =>Refresh.css(bg_unchecked_JSON), 1500);

}

}, 3000);

}, 2000);

要实现这个，首先你得保存变化前的那一次的值是多少，然后每次刷新去比对值，再判断

你这1s刷新一次，这大屏挂几个小时就会卡死~