User manual

Flow Chart Techniques
2373_en_B PHOENIX CONTACT 4-3
4 Flow Chart Techniques
This section provides an in-depth discussion of the flow charting features of nanoNavigator.
4.1 Basic Flow Chart Blocks
The first block in a flow chart is the starting point of execution. nanoNavigator automatically
creates the Enable block at the top of the flow chart when creating a new flow chart.
4.1.1 Enable Block
Each flow chart must have a beginning point, and the Enable block serves that purpose. The
Enable block is in the upper-left, grid cell A0, in a new flow chart (see Figure 4-1). It has the
following characteristics:
– The Enable block is the first block of every flow chart. It has a single exit from which flow
passes on to the rest of the control program. The Enable block cannot be deleted,
copied, or moved on the drawing area.
Figure 4-1 Every new flow chart opens with a predefined Enable block
– An empty Enable block (no expression created) causes a flow chart to always run.
– Double-click the block to edit its expression.