January 2012 8.35 Program Structures 1745
8.35 Program Structures
To design an easily understandable program, divide it into program sequences.
Use labels (LBL) as well as conditional and unconditional jumps. If you use
structured statements, the compiler creates the labels and jump commands.
Remember that using these labels and jump commands reduces the number
of available labels accordingly. You can nest structured statements in up to 16
levels. It is not possible to share levels.
Example:
The statements IFT, IFF, WHILET, WHILEF, ENDW, UNTILT and UNTILF
require a valid gating result in the logic accumulator. They conclude the
sequence of gating operations. The statements ELSE, ENDI and REPEAT
require that all previous operations sequences have been concluded.
Correct program structure Incorrect program structure
IFT IFT
WHILEF WHILEF
ENDW ENDI
ENDI ENDW
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