DO n... (EXIT)... ENDDO loops 
DO n... (EXIT)... ENDDO loops
To repeat CATT functions, you can put them in a loop.
Enter the DO function in the Funct. field, and the desired number of loop iterations in the Object field in the function maintenance screen. You can enter a number between 1 and 999.
Enter the CATT functions which are to be repeated.
End the loop with ENDDO.
The special variable &LPC contains the current loop counter.
DO 5
REF K1100001
ENDDO
The test module K1100001 runs five times.
You can nest DO...ENDDO loops and
EXIT
If a loop is to be conditionally ended, you can enter the EXIT <condition> function
between DO and ENDDO (see EXIT - Conditional termination). The condition is checked in each loop iteration. If the condition is satisfied, the loop is immediately ended, and the statement after ENDDO is executed.