If your iPad is set to lock automatically, you are likely to experience one or more of these issues:
Screen turns black
POS disconnects
iPad requests TouchID or Apple PIN
To prevent this, turn off Auto-Lock:
Go to the iPad settings
2. Go to Display & Brightness
3. Click Auto-Lock
4. Set Auto-Lock to Never
Now your iPad won't automatically lock, but it's still a good idea to turn the screen off outside of operations!