How to get Mendix to default to a response after a timeout?
As Stephen mentioned in comment above you can use 'Microflow Timer widget' and place it on the page that is presented. Further as shown in the widget settings below you can define how often you want to call the microflow and configure other settings. Then create a microflow and add your logic ( whatever response you want to execute if time out occurs).
Mohammed Siddiqui - 'Old Account'
You can use the idle timer widget from the appstore. It logs out after a configurable time