Variable options
This parameter contains bit-coded setting options for a process variable.
| Parameter name | Bit | Description of the |
|---|---|---|
| Do not make available as a public variable in the variable server | 0 |
The variable server itself can be addressed as an OPC server. If this setting is made in the variable options, the process variable is not made available for external client applications that use the variable server as an OPC server. This option is not supported by structure elements. |
| Record value changes in the log server | 1 | When using the protocol server, a value change is recorded in this process variable. |
| Suppress element resolution in favour of power tag counting | 2 | A process variable that is only required as a complete structure or field in the application can be assigned this setting. As a result, the entire process variable is counted as just one power tag in the licensing check. However, the resolution of the process variables into their elements between the variable server and the application is no longer supported. The connection of control elements to the elements of the process variables, for example, is then no longer possible. |
| Client-internal | 3 |
If the option is active, the variable client buffers the process variable without the help of the variable server. In a client-server system, the process variable is therefore not stored in the variable server for all clients. The process variable can therefore take on an individual value in each client application. This option can only be set for internal variables. This option is not supported by structure elements. |
Typical applications for the option Suppress element resolution in favour of power tag counting are:
-
Variable fields e.g. for the XYGraph
-
Fields and structures that are not required in the display but are called up via VWGet/VWSet.
If the option is active, the following functions can no longer be executed on the elements of the variables:
-
Link to display elements in the VWItem properties
-
Linking with definition functions (e.g. use of the elements as event variables for alarms)
-
Reading/writing the individual elements via VWGet/VWSet
The variables counted by the system are displayed in the Runtime Licensing dialogue. This dialogue is opened via the context menu of the top node <Project name> in the VisiWin project explorer.
The client-internal option is usually used for control variables in the client-server system.
Example: In a client-server project, a variable is used to control the switching of a unit conversion. However, the unit is to be switched individually for a client application. To prevent the variable from switching the unit conversion of all client applications involved, the control variable is marked as client-internal.
Parameters for module: