The UAPDIFF is a machine located in the smart buildings and electrification laboratories of ABB S.p.A (Vittuone). The purpose of this machine is the automation of tests on the tripping current and tripping times of residual current circuit breakers. These tests are currently carried out by hand by operators, as the machine has limitations and malfunctions, it also has no documentation, no operating instructions, and the manufacturer is now bankrupt. The presented thesis is a continuation of another one, more focused on explaining the functions, the hardware and software structure and the operating state of the machine. This work, instead, involves improving some of the machine's functions, such as generating clearer and more readable reports at the end of the tests, and correcting, as far as possible, the malfunctions of one component of the machine, the linear amplifier (DANA).