Define global parameters and variables

A global parameter or variable is a parameter or variable that has the same value for all model instances on the Canvas. For example, if you define the ambient temperature, Tamb, as a global parameter, you can update its value for one model instance and AVEVA Process Simulation applies that change to all model instances on the Canvas that contain the Tamb parameter.

Only Model Editors can define a parameter or variable as a global parameter or variable. However, Simulation Builders can turn on or turn off the tracking for a global parameter or variable for any model instance on the Canvas. For example, if you define the pipe size as a global variable, you can choose whether a Pipe on the Canvas tracks and uses the value of this global pipe size or maintains its own value for the pipe size separate from the global pipe size.

On the Mini Inspector and the Properties Inspector, the Global badge appears next to global parameters and variables. The color of this badge indicates the tracking status of the global parameter or variable for the associated model instance. If the badge is colored, the model instance tracks and uses the global value. If the badge is blank, the model instance maintains its own value separate from the global value.

You can turn on or turn off the tracking for a global parameter or variable by using the Properties Inspector for a model instance. Please see Change the tracking for global parameters and variables for more information.

If you have more than one Model Type that contains a parameter or variable that you want to define as a global parameter or variable, you should define that parameter or variable as a global parameter or variable in all the Model Types. Otherwise, the global parameter or variable won't track across to the model instances that are based on a Model Type that does not include the global definition for that parameter or variable.

Currently, you can define only Real and Enumerated parameters as global parameters.

Define a parameter as a global parameter

1. Ensure that the Model Writing role is selected. See Roles, Roles.

2. Open the Model Editor for the desired Model Type.

3. Expand the Parameters section.

4. Select the Global icon to flag the parameter as a global parameter.

Define a variable as a global variable

5. Ensure that the Model Writing role is selected. See Roles, Roles.

6. Open the Model Editor for the desired Model Type.

7. Expand the Variables section.

8. Select the Global icon to flag the variable as a global variable.