Rockwell Automation 1771-DB Basic Module User Manual - Series A - Manual (Page 61)

Operating Functions
Chapter 5
5–24
RETURN
Use this statement
to “return” control to the statement following the
most recently executed GO SUB STATEMENT. Use one return for each
GOSUB to
avoid overflowing the C-STACK. This means that a
subroutine
called by the GO SUB statement can call another
subroutine with another GOSUB statement.
Examples:
SIMPLE SUBROUTINE NESTED SUBROUTINES
u10 FOR I=1 TO 5 u10 FOR I=1 TO 3
u20 GOSUB 100 u20 GOSUB 100
u30 NEXT I u30 NEXT I
u40 END u40 END
u100 PRINT I u100 REM USER SUBROUTINE HERE
u110 RETURN u105 PRINT I,
uRUN u110 GOSUB 200
1
u200 PRINT I,I*I
2
u210 RETURN
3
uRUN
4
5 1 1
2 4
READY 3 9
u
READY
u
Mode: COMMAND AND/OR
RUN
Type: CONTROL
The GOTO [ln num] statement
causes BASIC to transfer control directly
to the line number ([ln
num]) following the GOTO statement.
Example:
u50 GOTO 100
If
line 100 exists, this statement causes execution of the program to
resume at line 100. If line number 100 does not exist the message ERROR:
INVALID
LINE NUMBER is printed to the console device.
5.4.12
Statements: GOSUB [ln num]
– RETURN (continued)
5.4.13
Statement: GOTO [ln num]