Connection points are the start or end points of lines or nodes on the line itself.
The output connection point (short: output) of an FBD-element is connected by a line to the input connection point (short: input) of the other FBD-element.

Connected inputs and outputs of an FBD-element are always displayed as part of the line (see the inputs of the ADD block in the following illustration). In contrast to this, connection points on the line or at the start/end of an open line are displayed as red nodes .

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.

Connection points on a line are necessary in order to create a line fork. A connection point at the start or end of an open line can be used in order to dock the line to other FBD-elements.