Parameter objects are just holders for settings that influence certain aspect of how QuickOPC works (for example, timeouts).  There are several types of parameter objects (such as Timeouts, HoldPeriods, and more). For more information on their details, see the “Setting Parameters” and “Advanced Topics” chapters, and also the Reference documentation.

The parameters of all EasyXXClient objects are consistently organized into three groups:

• SharedParameters (static parameters that are always shared among object instances),
• InstanceParameters (parameters that can always be set independently for each object instance), and
• AdaptableParameters (parameters that are normally shared, but can be made specific to an instance if the Isolated property is set to ‘true’).

An instance of any EasyXXClient object that is not isolated (i.e. has its Isolated property equal to ‘false’, which is the default) actually uses following settings:

• Shared parameters from the static property EasyXXClient.SharedParameters,
• adaptable parameters from the static property EasyXXClient.AdaptableParameters, and
• instance parameters from its instance property EasyXXClient.InstanceParameters.

An isolated instance (i.e. an instance which has its Isolated property explicitly set to ‘true’) of any EasyXXClient object actually uses following settings:

• Shared parameters from the static property EasyXXClient.SharedParameters,
• adaptable parameters from its instance property EasyXXClient.IsolatedParameters, and
• instance parameters from its instance property EasyXXClient.InstanceParameters.

In QuickOPC.NET, there are sometimes useful conversions and implicit conversions that allow you to easily construct parameter objects. For example, the DAGroupParameters object has a FromInt32 static method, and a corresponding implicit conversion operator, that allow it be constructed from an integer that represents the requested update rate (in milliseconds). This means that in C# and many other languages, you can simply use an integer update rate at all places where DAGroupParameters object is expected, if you are fine with specifying just the update rate and keeping the other properties of DAGroupParameters at their defaults.

All parameter and policy objects (and their constituents) consistently have a static Default property. This allows for a cleaner code where an arguments is needed, but you want to supply a default (there is no need to call the default constructor).

All parameter objects consistently derive from a Parameters base class. This class has a StandardName property (a string). The standard name identifies certain well-known combination of parameter values. When all the parameters correspond to a well-known combination, the StandardName property contains a symbolic name of such combination; otherwise, it contains an empty string. You can also set the StandardName property yourself, and the parameter values will change to reflect the name.

Some other objects that have similar nature also derive from the Parameters base class.