Ladder Logic / Function Block Diagram (Lad/Fbd) - Siemens SIMOTION SCOUT Configuration Manual

Introduction
3.4 Programming languages
Additional references
Detailed information can be found in the SIMOTION SCOUT online help and in the SIMOTION
MCC (Motion Control Chart) Programming and Operating Manual.
3.4.3

Ladder Logic / Function Block Diagram (LAD/FBD)

LAD/FBD is a graphical programming language and is available for Ladder Logic / Function
Block Diagram. The statement syntax corresponds to a circuit diagram (LAD) or a function
block diagram (FBD). LAD/FBD enable simple tracking of the signal flow between power rails
via inputs, outputs, and operations. LAD and FBD programs are usually suitable for application
in cyclic tasks (in particular, BackgroundTask).
LAD/FBD programs consist of elements and boxes that are graphically connected to networks.
Their operations work mostly according to the rules of Boolean logic or simple arithmetic
expressions and equations. Therefore, they are suitable only for control-relevant programs or
also for motion control tasks by using the PLCopen blocks.
Functions, function blocks and programs can be programmed in LAD/FBD. A source can
contain several LAD and FBD blocks. Only one POU can be implemented in an LAD or FBD
block.
LAD/FBD also include commands for SIMOTION system control using standard logic
functions. These commands are added from the command library. Motion Control tasks are
preferably programmed with PLCopen blocks. Blocks which have been programmed in other
SIMOTION languages can be called. User-friendly functions such as "on the fly" variable
declarations or automatic syntax checks are available when programming in LAD or FBD. It
is possible to switch over between LAD and FBD in the editor at any time. A program can
therefore be viewed and processed in either LAD or FBD.
The following user-friendly debug functions are available for online testing and diagnostics:
● Program status
● Breakpoints
Note
Direct editing of motion commands is not recommended. Instead, it is better to use the
PLCopen blocks. These blocks are designed for integration in logic-oriented programs.
Additional references
Detailed information can be found in the SIMOTION SCOUT online help and in the SIMOTION
LAD/FBD Programming and Operating Manual.
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SIMOTION SCOUT
Configuration Manual, 11/2016