HAI thermostats can be integrated with a Cortexa in two different manners: direct connection to the Cortexa via serial connection, or integration through an HAI or ELK security panel. The preferred method is a direct connection to the Cortexa. This document will cover integration through the direct connection method, as well as configuration steps that apply to either method. Please refer to the security panel’s documentation for assistance with connecting thermostats to an HAI or Elk security panel.

Pre-Wire Basics

Each HAI communicating thermostat will require a dedicated communicating wire run from the thermostat location to a central point, ideally next to the installation location of the Cortexa. If the wires are not run to the location of the Cortexa, an additional 4 wire cable run will need to go from the Cortexa to the Central Location.

Only 4-wires will be needed for communication. Use 22 to 24 gauge shielded or unshielded, stranded or solid, twisted or untwisted - the wire type is not critical. CAT5(24 gauge twisted pair) can be used if desired.

Use shielded wiring if the installation environment calls for running the communications wire along with power wires, and connect the shield to a good ground at the computer. Do not connect the shield at the thermostat.

HAI Thermostats

There are two generations of HAI thermostats that can be integrated with the Cortexa:

    •    Omnistat 2 – RC-1000 and RC-2000
    •    Omnistat 1 – RC-80 and other models (no longer manufactured)

The main difference in integration between the Omnistat 1 and Omnistat 2 is the pin outs with the serial communication cable. This document covers Omnistat2 pin outs (except where otherwise noted).

Thermostat Basics

On one level, HAI communicating thermostats operate as regular thermostats:

    •    the thermostat typically draws power from the unit 
    •    the thermostat can be set to run in many different operation modes, just like any standard thermostat. 

Screw terminals for connection to the home’s air handler are located on the left side of the thermostat wall-plate.
The communicating connections reside on the right side of the thermostat back-plate. The four terminal posts used for communicating with Cortexa are terminals 4-7 starting from the bottom (labeled YELLOW, GREEN, BLACK, and N/C). Please note that the colors referred to in these labels (and referenced in the thermostat manual) are not correct for direct communication between the Cortexa and the thermostat(s).

Limitations on number of Thermostats and length of Wire Run

There are two limitations when connecting HAI Thermostats.

    •    A maximum of 4 HAI thermostats can be connected to the Cortexa without the need for a booster
    •    The total length of cable runs to all thermostats cannot exceed 500 feet without the need for a booster. 

If either of these parameters are exceeded, or if significant signal loss occurs for any other reason, a signal booster for HAI Thermostats (HAI p/n RC-202) will need to be installed for successful integration.

Connection to the Cortexa

The connecting end of the HAI thermostats into the Cortexa needs to be a serial (DB9) connection. There are multiple ways to create or purchase the needed serial connection end:

    •    Purchase the HAI RC-201, 10’ Thermostat Serial Cable. 
    •    Create a custom Serial Cable soldering a single Female DB-9 connector with the wiring as described below
    •    Create a custom Serial cable using a Female db-9 Pinout connector 

All of these connectors will have a Female db-9 connector on one end and open wires on the other end. Multiple thermostats are connected in parallel to the connector with all similar wires connecting to each other in a terminal block (preferred) or within a beanie.

Wiring

Wiring is the most complicated step in the setup process, and it is the most likely reason for communication to fail. This section will be broken down into the serial pin-out and the thermostat pin-out. A final section will bridge the two previous sections, and will give specifics to test for.
Serial Pin-out (extracted from HAI Documentation):

    1. At the DB-9F connector: Connect pins 7 and 8 together.
    2. At the DB-9F connector: Connect pins 1, 6 and 4 together.
    3. Connect pin 4 of the DB-9F to the YELLOW wire
    4. Connect pin 3 of the DB-9F to the GREEN wire 
    5. Connect pin 2 of the DB-9F to the RED wire 
    6. Connect pin 5 of the DB-9F to the BLACK

If using Cat5 to connect the thermostat, any consistent convention will work. One example that will be carried throughout this document is:

    • Cat5 Green = Green, 
    • Cat5 Green/White = Yellow, 
    • Cat5 Blue = Black
    • Cat 5 Blue/White = Red. 

The pin-outs for the Cat 5 example above should be as follows:

    1. At the DB-9F connector: Connect pins 7 and 8 together.
    2. At the DB-9F connector: Connect pins 1, 6 and 4 together.
    3. Connect pin 4 of the DB-9F to the Cat5 Green/White wire on the thermostat plug 
    4. Connect pin 3 of the DB-9F to the Cat5 GREEN wire on the thermostat plug 
    5. Connect pin 2 of the DB-9F to the Cat 5 Blue/White wire on the thermostat plug
    6. Connect pin 5 of the DB-9F to the Cat 5 BLUE

The open-ended wires will connect to the wires coming from the thermostat. See the section below on how to connect the thermostat communication wires

Thermostat Pin-out (extracted from HAI Documentation)

Each thermostat will have a communication cable that runs to the central location. The end at the central location will connect to the serial connector, and the other end will connect to the thermostats.
The following two jumpers need to be removed to ensure proper communication:

    • Remove the jumper on the communication terminals (discard or put in a safe place)
    • If the thermostat is Rev. 1.03C or later, remove Jumper 8 (J8 on lower left side) bridging the pins called COM (ver. previous to 1.03C did not have Jumper 8).

The Omnistat2 connection requires a different configuration than what is labeled on the wall-plate and what is shown in the HAI instruction manual. The instructions included with the thermostat typically refer to connecting the thermostat to a security panel rather than to a Cortexa.
For thermostat wire on an Omnistat 2 (RC-1000/2000) connect the wires as follows: (terminals are counted from the bottom of the thermostat plate):

    • Yellow wire goes to terminal labeled YELLOW (Terminal 4)
    • Green wire goes to GREEN (Terminal 5)
    • Red wire goes to terminal labeled Black (Terminal 6)
    • Black wire goes to terminal labeled N/C (Terminal  7) 

When using CAT5 wire on an Omnistat 2 setup and using the color conventions described in these instructions, connect the wires as follows: (terminals are counted from the bottom of the thermostat plate):

    • Green-White wire goes to terminal labeled YELLOW (Terminal 4)
    • Green wire goes to GREEN (Terminal 5)
    • Blue-white wire goes to terminal labeled Black (Terminal 6)
    • Blue wire goes to terminal labeled N/C (Terminal  7)

Legacy Omnistat1 wiring is also included below for reference.
For thermostat wire on an Omnistat1 (RC-80), connect the wires as follows to the 4-pin connector that comes with the thermostat: (terminals are counted from the bottom of the thermostat plate):

    • Yellow wire goes to YELLOW lead from RC-80 4-pin connector 
    • Green wire goes to GREEN lead from RC-80 4-pin connector
    • Black wire goes to BLACK lead from RC-80 4-pin connector
    • Red wire goes to RED lead from RC-80 4-pin connector

For CAT5 wire on an Omnistat1 (RC-80), connect the wires as follows:

    • Green-White wire goes to YELLOW lead from RC-80 4-pin connector 
    • Green wire goes to GREEN lead from RC-80 4-pin connector
    • Blue wire goes to BLACK lead from RC-80 4-pin connector
    • Blue-White wire goes to RED lead from RC-80 4-pin connector 

Bridging the two wires

Bridge the two sets of cables together. The thermostat wires will be in parallel to each other when connected to serial end. Simply match all wire colors together in a terminal block or with plastic connectors.
The individual pins on the serial connector can now be tested on the thermostat back panel for continuity. The listing below refers to an Omnistat2.

    • DB-9F Pin 1 continuous with DB-9F Pin 6 and Pin 4 and Thermostat Terminal 4 (labeled Yellow)
    • DB-9F Pin 2 continuous with Thermostat Terminal 6 (labeled Black)
    • DB-9F Pin 3 continuous with Thermostat Terminal 5 (labeled Green)
    • DB-9F Pin 5 continuous with Thermostat Terminal 7 (labeled N/C)
    • DB-9F Pin 7 continuous with DB-9F Pin 8
    • DB-9F Pin 9 is not connected to another pin or terminal92

Thermostat Configuration

To properly communicate with a network of thermostats, each thermostat must be set to the following settings:

    • Communications: Serial
    • Baud Rate: 300
    • Expansion Baud: 1200

Additionally, each thermostat must have a unique address and all address numbers must be sequential without any break in address numbers. For example, if 6 thermostats are installed, thermostats can only have an address of 1-6.