So, I have done the following and received the following error message.
Inside of terminal.c I have placed
1) unsigned char Pan_Angle
Inside of user_routines.c I have placed
2) extern unsigned char Pan_Angle
and I received the following error message.
user_routines.c:566:Fatal [151] -internal p
opulateExternalReferences() - symbol 'Pan_Angle' is not an external reference.