CAAPE User's Manual - ALSTOM Signaling Inc.

General Rules and Techniques5.2.3. Subroutine ArgumentsIn non-vital applications the same symbol name can be used in the argument lists ofmore than one subroutine declaration. This is because a subroutine argument existsonly within the scope of the subroutine that contains it. For example, declaring twosubroutines with argument “X” as shown below is allowed because there are really two“X” variables: the SUBRT1 argument variable and the SUBRT2 argument variable.The subroutine format is:SUBROUTINE SUBRT1(BOOL X)…END SUBRT1SUBROUTINE SUBRT2(BOOL X, INT Y)…END SUBRT2.5.2.4. ArraysArrays of internal variables can be declared in non-vital applications. Array elementscan be used in equations and also in output ports and outgoing message bits.5.2.5. PERMONE / PERMZEROPERMONE indicates a Boolean value that is always True and PERMZERO a value thatis always False. PERMONE and PERMZERO can be used in place of variable names insome cases such as message bits or I/O ports; the rules governing where they can beused depend on the application.5.2.6. Symbol TableEach CAAPE project maintains a master list of all the symbol names used throughoutthe project. The user can access this master list of names in graphical editing to findalready-entered names.5.3. I/O WIRINGIn general, I/O boards have a number of input or output ports which may be arranged ingroups. Groups have common wiring to provide energy to their ports. Group data mustbe entered when data for any port in the group is entered.Wire names must be no longer than 16 characters and can have no embedded blanks.The ‘+’ character is allowed.P2512A, Rev. Oct/09 5–3 Alstom Signaling Inc.