## JA5.1 Introduction

The Occupant Controlled Smart Thermostat (OCST)1 shall be self-certified by the manufacturer to the Energy Commission to meet the requirements described in this section. This document provides a high level technical specification for an OCST. All OCSTs shall comply with the specifications set forth in this document or a specification approved by the Executive Director. This specification focuses on three interfaces that the Energy Commission has determined shall be supported by all OCSTs:

(a) Communications Interface

(b) User Display and Interface

(c) HVAC System Interface

Sections within this document address each interface in terms of its hardware and software characteristics. This specification is intended to compatible with National Electrical Manufacturers Association (NEMA) Standards Publication DC 3-2013 – “Residential Controls – Electrical Wall-Mounted Thermostats”2 unless otherwise specified.

The Communications Interface is comprised of the (1) physical communication interface and the (2) logical communication interface.

(a) The physical communication interface describes the physical connection that enables receipt of demand response signals or price signals.

(b) The logical communication interface describes the information model and its messaging protocol used for representation and interpretation of signals received by the OCST.

See Section 5.3.1 for a more detailed explanation of these communication interfaces.