The general format of a function is
FunctionName(Parameter1, Parameter2, ...etc );
Function parameters are separated by commas and may be constants, variables, I/O tags, modules or other functions, as shown:
Date(DateNum(25, 12, 1995), Cond(Valid(option), option, 2));
This illustrates the concept of nested functions.
Functions that do not require any parameters may be written either with or without an empty set of parentheses, however, including the parentheses precludes mistaking the function for a variable:
Seconds();
Seconds;