Parapet designs with crenulations sample plans

[Katalyst777]

I don't know if there are any "sample" plans that show what you want, but you should be able to do it using the instructions for creating a parapet.

Article Number 120: How to make a simple flat roof parapet wall structure

You can use the Break Wall tool along the solid railing to create breaks, so you can set the heights for different sections to create the castle wall look.