Symbols

An SCL symbol is a user-defined name for an item such as a variable, timer, or label. During compilation, the compiler maintains tables of all the defined symbols it has encountered, so that it may resolve references to them.

There are separate symbol tables for variables, timers, and labels. All symbols within an individual symbol table must be unique. Symbols can be duplicated across separate symbol tables though. This allows the same symbol name to be used for a label, variable, or timer.

Furthermore, because labels are not propagated into subroutines or vice versa, labels within a subroutine may duplicate labels within other subroutines, or within the main body of the code.