You can take two TON timer on delays and tie them together to make a PLC flasher.

This is the most common way to make a light flash on and off and you will find it in most PLC programs. It only takes two simple rungs to make a flashing beacon or pilot light. This universal method works with Studio 5000, RsLogix 5000, RsLogix 500, Connected Components Workbench, and most other brands of PLCs.