Electric energy remote terminal unit（ERTU）， an important plant-level device for periodic data acquisition of substation， is obviously a part of digital substation system. However， as the basis of digital substation， IEC 61850 has not covered all measurement of quantities of substation electric energy. Therefore， based on IEC 61850 standard extend principle， a new common data class（CDC） FEE， a series new data object（DO）， and a new logic node（LN） MEEE， are introduced to build a complete ERTU object model and its instance. Such extension meets the principle according to corresponding articles in IEC 61850. In accordance with the practical application demand and analysis of digital energy meter as well as ERTU， a complete data service scheme using URCB controlled report and LOG mechanism based on a series DATA-SET definition， is designed for periodic data communication between energy meters， ERTU， master station. A novel ERTU based on above modeling was developed and implemented in a 110 kV substation in Zhejiang Province.