The Self Timer mode enables you to trigger the camera after the timer goes off. It has a single parameter:
Timer: This parameter is used to set a timer up to 100 hours in milliseconds. When the timer goes off, the camera will be triggered once.
The Self Timer mode does not have any exposure parameter. It will only trigger the camera for pulse length duration. When you start the timer, a circle will appear at the bottom of the screen. The circle will show the progress of the time and it will count down from the timer value.