Introduction

The M580 safety PAC includes three different data editors:

  • a Safety Data Editor to manage data used in the safe namespace.

  • a Process Data Editor to manage data used in the process namespace.

  • a Global Data Editor to manage global variables and data types used throughout the application.

Both the Safety Data Editor and the Process Data Editor include an Interface tab. Use the Interface tab to create unlocated variables in that process namespace. The Interface tab presents two groups of unlocated variables:

  • <inputs>: A variable created in this group can be linked to, and receive data from, a globally scoped pass-through variable in the Global Data Editor .

  • <outputs>: A variable in this group can be linked to, and send data to, a globally scoped pass-through variable in the Global Data Editor.

NOTE: A variable created in either Interface tab needs to be all of the following:

  • An EDT or DDT category variable.

  • Of the same data type as the variable to which it is linked.

  • Not a variable linked to an extracted bit of a located variable (for example, not %MW10.1).

Unlocated variables created in the Interface tab groups of the Safety Data Editor and Process Data Editor can be linked as follows:

A process variable in this group in the Process Data Editor...

Can be linked to a safety variable in this group in the Safety Data Editor...

<inputs>

<outputs>

<outputs>

<inputs>

Using these three data editors, you can configure the transfer of data between the safe namespace and the process namespace.

Transferring Data Between Namespaces

The process for passing data from the safe to the process namespace, and from the process to the safe namespace are the mirror image of each other. The following example shows you how to pass data from the process to the safe area:

Step

Action

1

Open the Process Data Editor, click on the program Interface tab and then create a new variable in the <outputs> part of the data editor.

2

Open the Safety Data Editor, click on the program Interface tab and then create a new variable with the same type of the one created in step1 in the <inputs> part of the data editor. Then, double-click the Effective Parameter field. The Data Scope Editor: Variable Selection dialog opens.

3

In the drop-down menu at the top-right of the dialog, select the target namespace PROCESS. The variables in the selected namespace PROCESS in the <outputs> part are displayed.

4

Select the process variable created in step1 to be linked to the safe variable you created in step2, then click OK. The selected target variable appears in the Effective Parameter field.

5

Save your edits.

After you compile, download and run the edited application program, the value is transferred as follows:

  • The data from the Interface tab created in the <outputs> are published at the end of the corresponding task execution.

  • The data from Interface tab created in the <inputs> are subscribed at the beginning of the corresponding task execution.