Introduction

Links are vertical and horizontal connections between FFBs.

Attention should be paid to the following programming information:

  • Links can be used for every data type.

  • The data types of the inputs/outputs to be linked must be the same.

  • Several links can be connected with one FFB output. However, only one may have an FFB output.

  • Only inputs and outputs can be linked together. A link between several outputs cannot be made. This means that OR links are not possible using links in FBD. An OR function should always be used.

  • An overlap of links with other objects is permitted.

  • No loop can be configured with links because in this case the execution sequence in the section cannot be clearly determined. Loops must be terminated with actual parameters (see Terminating loops).

  • To avoid links crossing each other, links can also be represented in the form of connectors.

NOTE: A detailed description about Links can be found in the Reference manual.

Selecting links

You have the following options to activate the placement mode:

  • Use the Edit > New > Link menu command.

  • Press the F6 key.

    or

  • Select the symbol.

The and cursor symbols indicate which mode is active.

Representation

The link points are identified by a filled-in circle.

Crossed links are indicated by a "broken" link.