12 POU Editing ModeDVP-PM Application Manual12-212.1.1 Function of SymbolsUsers can declare and define the symbols by local symbol table and global symbol table. Local symbols are applicablefor the current editing window and global symbols are applicable for all POUs in the program. Local Symbols:POU function operates in both Program and Function Blocks. Therefore, local sy mbols exist in both editingwindows of program (O100, Pn subroutine, OXn subroutine) and function blocks. However, usage of local symbolsdiffers in the two editing windows and is explained below.1. Local symbols in Program:(1) Only VAR is available for Class and the setting is only for internal use of current program.(2) All columns of Address should be filled.2. Local symbols in Function Blocks(1) VAR, INPUT, OUTPUT and INOUT are available for the column of Class.VAR: available only in current function block.INPUT: stores the input data of current function blockOUTPUT: stores the output data of current function blockINOUT: operates the input data and output the data after the calculation.(2) The column of Address can be blank.(3) When INPUT or OUTPUT is specified as the Class of symbols, the function block will utilize the symbols asthe input or output interface as the diagram below.
