Polybench® for biosignals / reference 1.34.1
A concept of system-wide parameter access, so that settings of operators and the system can be read and modified by other components.

Variable Parameters


Variable Parameters are settings of objects that can be changed from within a measurement configuration, as opposed to properties that can only be changed by the User. Using Variable Parameters it is possible for one object to change the behavior of another object.


To view which Variable Parameters an object has, click right on the object and see if the menu says 'Variable Parameters...'. If it does and if you select that item, the Variable Parameter Dialog opens, in which you can view and try the variables and copy their addresses. For more info see "Variable Parameter Viewer".

Variable Parameters are commonly referenced by their system address, which is a text line that specifies in which component the variable is located. Such an address always starts with a dollar sign '$' and if the variable is used inside a text, also ends with a $.
For example, if you have a Constant operator on the Design page, called Constant 1, then you can refer to its Value parameter as follows:

$Design.Constant 1.Value
Or as part of a text: The value of the constant is $Design.Constant 1.Value$.

If a Variable Parameter is not read-only, then it can also be changed from within your application. To do that, use the SET_PARAMETER action ("SET_PARAMETER"). For more information about Actions, see "Actions - Overview".

Further reading

Variable Parameters are most often single value, but they may also be array-values. In that case, the variable contains a list of sub-values. This is explained further in Parameter Lists ("Parameter List").

Not only objects may offer variable parameters - also the application itself offers them. There are a number of pre-defined global variables, but you may also define your own global variables. Read more about this in Global Variables ("Free Global and Namespace Variables").