When logging on to Spotfire tick the checkbox "Keep me logged in", the checkbox works best with Microsoft Internet Explorer.
If the browser refresh frequency is set to less than the default value of inactivityTimeout (2 hours) then there is no need to modify service configuration files for the Web Player where the dashboard is going to be routed.
Example of script to reload browser every 25 minutes:
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="X-UA-Compatible" content="IE=Edge" />
<script>
<!-- Will make the browser reload the page once every 20 minutes -->
setInterval(function () {
location.reload();
}, 1000 * 60 * 20 * 1);
</script>
</head>
<body>
<iframe src="link to your dashboard" width="1600" height="1000"></iframe>
</body>
</html>