Javascript run function one time in another function which sets as interval

hi i am using selenium chrome driver in my js. And i am checking value in website in every 2 seconds. here is my code. Value is checking every 2 seconds. and it has two value. like online or offline. i want write to text file for status changes. not for every check. here is my code. it is working but it save text file every two seconds. i want check every two seconds but i want save it in text only status changes. help me pls.

setInterval(MyControl, 2000);

function MyControl() {
  var x = browser.findElements(By.className("textclass")).then(function(divs) {
    // console.log("yy:",divs.length);
    var d = new Date();
    if (divs.length == 1) {
      divs.forEach(function(element) {
        element.getAttribute("title").then(function(text) {
          console.log(text, " Control Time :", d.toLocaleString());
          //    playSound();

          fs.appendFile('mytextfile.txt', text + " Control Time: " + d.toLocaleString() + '\n', function(err) {
            // console.log("/////////////////////////////////////");
            if (err) throw err;
          });
        });
      });
    } else {
      console.log("There isnt any info :" + "Control Time :" + d.toLocaleString());

    }
  });
}