Installation Instructions

Table Of Contents

Pro1 Wireless Thermostat and Base Module

Theory of Operation

Page 1 of 2

Introduction

The Pro1 Wireless Thermostat and Base Module form a HVAC system controller designed to work with

Packaged Terminal Air Conditioners (PTACs). The thermostat communicates with the base module using

a 915 MHz, single frequency, wireless link. Both the thermostat and the base module contain a S2-LP

transceiver from ST Microelectronics and both are set up to transmit and receive data to/from each

other. The base module also contains an AW-CU300 WiFi module from Azurewave that is co-located

with the S2-LP transceiver. The base module acts as a WiFi client to communicate with a WiFi access

point (gateway) for remote monitoring and control. The thermostat may be powered by 2, AA batteries

or connected to 24 VAC from the HVAC system. The base module is powered by 24 VAC from the HVAC

system and does not have an option for battery power.

Figure 1: Thermostat/Base Module System

915 MHz Wireless Link

The 915 MHz wireless link uses a proprietary protocol is designed to meet FCC part 15 subpart 249 (FCC

part 15.249). The S2-LP transceiver uses a 2-GFSK modulation scheme with a data rate of 4.8 kbps and a

frequency deviation of 2.5 KHz. Depending on the mode of operation, the system can use up to 5All

systems will communicate on the same TBD frequencyies in the 902-928 MHz ISM band. During initial

setup, the thermostat and base module communicate on TBD frequency at the maximum system power

output. Once the network is established, both the thermostat and base module monitor their RSSI and

packet throughput. These inputs allow each transmitter to adjust to the lowest possible reliable power

output for a given installation. Power output will never exceed the TBD maximum system output power

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Pro1 Wireless Thermostat and Base Module Theory of Operation Introduction The Pro1 Wireless Thermostat and Base Module form a HVAC system controller designed to work with Packaged Terminal Air Conditioners (PTACs). The thermostat communicates with the base module using a 915 MHz, single frequency, wireless link. Both the thermostat and the base module contain a S2-LP transceiver from ST Microelectronics and both are set up to transmit and receive data to/from each other.
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Pro1 Wireless Thermostat and Base Module Theory of Operation but may be reduced as much as 40dB in steps of 5dB. channel 0 (915.0 MHz). Once setup is complete and the thermostat is “paired” to the base module, the frequency used will change to one of 4 predefined channels that is determined by the base module’s unique ID (915.1, 915.2, 915.3 or 915.4 MHz). The frequency channel does not change during normal operation.