Problem
You want to use a function in a TwinCAT library. However, you can not access the function.
Solution
You need to add the library before before you can use the function.
- You need to figure out what library the function belongs to. Beckhoff System Information is a good place to start. It shows you what library the function belongs to. For example, the function to get and set TwinCAT device’s state is in TcEtherCAT.lib
- Click on insert in TwinCAT PLC Control.
Select Insert - Alternatively, you can click on Windows and Select Library Manager. Then Right click to select Add Library.
Add Library through Library Manager 
Right Click on Library Manager and Select Additional Library - Find the library file and hit on Open
Select Library - All the functions in the library are ready to be used.
Library Functions Ready
