This document provides a user manual for meter reading entry in SAP ISU. It describes the software and hardware environment required to run SAP ISU. It outlines user roles and access rights in SAP ISU. It explains how to log in to SAP ISU and navigate the interface. It provides details on the mass meter reading entry process in SAP ISU, including entering readings by meter reading unit or installation and saving the entries. Key aspects like using menus, shortcuts, and logging out are also covered at a high level.