From the manual:
AUTO-DETECT FEATURE (temp control mode versus wattage mode)
The SnowWolf 200W auto-detects nickel or kanthal wire coils and fires each in the appropriate mode — temperature control mode for nickel and wattage mode for kanthal. The temperature setting will remain on the screen for kanthal builds until the firing button is activated. Then the temperature will vanish, indicating that firing is in wattage mode.
That's how mine works. If I'm running a nickel-coiled tank, take it off and put on a kanthal-coiled tank, the SnowWolf may or may not ask me if it's a new coil. If it does I say yes. If it doesn't ask, the correct resistance for the new coil is displayed anyway. Then I adjust the wattage down---I run TC on the SnowWolf at 400°F and 40 watts, while most of my Kanthal-built tanks run from 20-35 watts---and fire. During the first couple seconds of firing, the SnowWolf acts like it's still in TC mode, showing momentarily-lowered temps and wattages. Then it senses the kanthal and switches over to wattage mode, blanking out the temperature during firing, and providing full selected wattage.
When going back to a nickel-built tank, the switchover of modes has no delay: My SnowWolf always asks if the coil is new. I say yes, it senses the nickel coil, shows the correct resistance, and goes into TC mode immediately upon firing. On rare occasions, the SnowWolf doesn't ask if the coil is new. Then I have to disconnect the atty/tank by unscrewing it a turn or two and reconnect, after which the new coil question comes up.
I can imagine that it's a bit confusing for some people that the selected temperature remains visible on-screen when the display is active in either mode. When firing in wattage mode, however, the temp blanks out---that's how you know it's running straight watts---while when firing in temperature mode, the display shows the set temperature and varying wattages.