The USB analogue converter published in the November 2003 issue is a neat circuit for simple measurement and test purposes. The ActiveX component described here can be used to control this circuit from a high level language.oMany Elektor Electronics readers constructed this simple circuit, which makes it possible to easily measure analogue voltages and switch digital outputs via USB. Unfortunately, the associated Windows program had a limited functionality and it wasn't always stable. The author was inundated with questions about the program, which led to the development of a utility that allows a user of the USB analogue converter to write a control program for driving any peripheral.The ActiveX component described here can read in analogue values and drive the digital outputs. This type of control makes it possible to program the circuit from within any high level language, such as Delphi, Visual Basic or C++ by Borland.Since Delphi is one of the most commonly used programming languages, we'll take a look how we can use this language with the ActiveX component.