This article focuses on the review of the tool for describing onboard repeater schemes. The tool was developed using C++ programming language and cross-platform library - Qt. In addition, this article describes the commutation transponders algorithm, which allows switching devices by optimal way. The algorithm takes into consideration condition, characteristic and type of device while finding the solution. The result of the algorithm is the matrix of devices and calculated positions of the switches depending on the list of enabled devices. This article describes data format for representing circuit of the transponder in a text format. This approach allows creating program models of objects using the mechanism of serialization and deserialization and generating graphical representation of the circuit. The software package for monitoring and control onboard repeater was designed using this platform.