Managers have access to all scanner appliances automatically and can use them for scanning. Users with other roles do not. You must first grant the users access to appliances so they can use them for scanning. (Express Lite users always have access to all appliances.)
For Scanner users that are Unassigned:
1) Manager: Add the scanner appliances to one or more asset groups.
2) Manager: Edit each Scanner's account and add the asset groups (containing appliances) to the Assign Asset Groups list.
For Unit Managers and Scanners in a custom business unit:
1) Manager: Add the scanner appliances to one or more asset groups.
2) Manager: Edit the business unit and add the asset groups (containing the appliances) to the unit's Assigned Asset Groups list. This step grants Unit Managers access.
3) Manager or Unit Manager: Edit each Scanner's account and add the unit's asset groups (containing the appliances) to the Assigned Asset Groups list.