Initial steps and steps in FBD
Use an initial step and →steps in order to create a step sequence (an →SFC network).
Several steps are allowed per SFC network but only one initial step. See the notes under "SFC elements in drawing field" how to create/use SFC networks efficiently and correctly.
One or several →actions can be associated to each step (and each initial step as well). See "Evaluating the ST-code including the SFC networks" for information on when a step or initial step is active or inactive and the results of this.
Lines visualize the connections to the other FBD-elements in the drawing field.
Representation
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Example for initial step with name S0: |
Example for step with name S1: |
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The step input in is located on the top edge, the step output out on the bottom edge, the step marker output X on the right edge.
The step input and the step output are connected to →transitions, the step marker output is usually connected to an action block.
Restrictions
Currently, the connections to these SFC elements are not possible within logi.CAD 3 because the appropriate SFC elements are not provided.
Although the usage of the step marker X, of the step time T and of the time of activation S is possible according to the →IEC-standard, they cannot be used within the FBD-editor.
It is only possible to resize initial steps and steps regarding their width. It is not possible to resize them regarding their height.
Depending on the configuration of your logi.CAD 3 version, the FBD-editor and its elements might be displayed differently in your logi.CAD 3 version than illustrated in the IDE documentation. This is the case, if logi.cals or the system integrator has changed the styles for the FBD-editor. Subsequently, the illustration in the IDE documentation are symbolic images and the representation in your logi.CAD 3 version takes precedence for the valid representation. In case of doubts, please contact logi.cals or your system integrator.
logi.cals recommends that you and/or your system integrator do not use yellow shades when designing FBD-elements because the color "Yellow" is used for tracking safe signals when developing safety-related applications. logi.CAD 3 does not check if colors are already used elsewhere. So the use of the yellow shades by you and/or your system integrator could have the consequence that "yellow" might also identify a non-safe logic as well.
Actions for initial step and steps
Page:Moving FBD-elements