Source: One Step Solutions Knowledge Base
In order for an employee to check in, there must be someone logged into Retail Pro. It's best for the logged in user to have restricted rights. You could create a user called "checkin" with a simple password or no password, and assign that user to the POS group or a group with restricted rights. Then you would tell employees who just need to check in without logging in to use that user. Once they are logged in with that user, they can check in by choosing their username from the dropdown list in the Check-In/Out Module.