External classes let you use ActiveX controls and ActiveX automation in your OpenROAD applications.

ActiveX objects have properties, methods, and events just like other class objects. Therefore, they are treated as external classes in OpenROAD. Each unique ActiveX object used in OpenROAD must have an external class to represent it. The external class is viewed by OpenROAD as an actual system class. As such, external classes can be displayed and manipulated like any other class in the system.

External classes reside in a binary file (library or executable), which must have the same bitness (32-bit or 64-bit) as the OpenROAD version you are using.

The binary must have been registered in the Windows registry. A 32-bit binary on a 64-bit Windows system must be registered in the 32-bit part of the registry.

For more information about ActiveX, see the documentation supplied with the ActiveX object.