Cloud POS features a quick switch feature, so that the users do not need to fully log out of the Point of Sale to switch to another user.
Setting a pin number for the user
1) From the Back Office menu, expand the Users heading and then click on Users.
2) Click on the blue pencil icon next to the user that you wish to Edit:

3) Enter their chosen pin number into the PIN field, then click on Save.

4) You should also take note of their user number, shown here:

Please note the user number is not editable.
Switching User in the Point of Sale
That user will now be able to use the Switch User option in the Point of Sale menu:

This will prompt the user to log in using their user number and pin (or their full username and password can also be used):

It is also possible to use the Switch User function on completion of a transaction when you reach the Transaction Summary screen, as shown here:

Switch User - Keyboard Shortcut
There is also a keyboard shortcut to Switch User.
On Windows: CTRL+ ALT + Y
On Mac: CTRL + SHIFT + Y
Forcing Switch User after every transaction
If you wish to enforce this functionality, so that a user must log in after every transaction is completed, you can do this in the Cloud POS Back Office.
1) From the Back Office side menu, expand the Setup heading, then choose Configuration.
2) Under the section Cashier Settings, tick the box marked Force a cashier to quick (pin) login after each transaction.

3) Click Save Pending Change once you have made this selection.

Changing the setting for each register
This is a global setting, so it will be applied to every register at every store within your Cloud POS group.
To stop specific registers from forcing people to Switch User (for example, registers you may use to process internet orders), navigate to Setup, then Registers.
Click on the register you wish to exclude. Under the Register Settings section, tick the box marked Suppress Auto Logout and then click Save pending change.

Users using that register will remain logged in when a transaction is completed.