A standard or basic UPS typically uses a standby topology, meaning it passes raw mains power directly to connected equipment and only switches to battery when a fault is detected. This switch takes 10 to 20 milliseconds, which is fast enough for most desktop computers but not for sensitive server or medical equipment. The APC Smart-UPS uses line-interactive topology, which actively conditions incoming voltage using an autotransformer before it reaches connected equipment, correcting sags and surges without switching to battery. SRT-series Smart-UPS units use online double-conversion, completely isolating equipment from the mains at all times. The Smart-UPS also includes intelligent monitoring, network management capability, automatic battery testing, and software integration, none of which are found on basic standby units.