fix cutoff

backend/services/control/exporter_monolith.py

@@ -1651,14 +1651,16 @@ async def write_inverter_setpoints(
                 r179 = await mb179.read_holding_registers(179, 1, unit_id)
                 if r179 and len(r179) >= 1:
                     current_179 = int(r179[0])
-                    new_179 = (current_179 & ~REG179_MI_EXPORT_MASK) | int(target_bits)
-                    registers.append((179, "control_board_special_1", new_179))
+                    # Deye firmware/UI u některých instalací neinterpretuje jen bits0–1 maskou,
+                    # ale očekává přímo hodnotu 2/3. Proto zapisujeme "clean" 2/3 (bez RMW),
+                    # aby se cutoff skutečně projevil i v UI.
+                    registers.append((179, "control_board_special_1", int(target_bits)))
                     logger.info(
                         "[control] %s: reg179 MI cutoff %s (old=%s new=%s mask=0x%04X)",
                         inv.code,
                         "ON" if want_cutoff else "OFF",
                         current_179,
-                        new_179,
+                        int(target_bits),
                         REG179_MI_EXPORT_MASK,
                     )
                 else: