Daikin intelligent Touch Manager BACnet DCM014A51 Guide

Intelligent Touch Manager
BACnet® Server Gateway
DCM014A51
DESIGN GUIDE
DG_DCM014A51_02-17

Contents
Part 1. Overview.......................................................................................................................................... 6
1. DCM014A51 iTM BACnet® Server Gateway ......................................................................................... 6
1.1 Features ........................................................................................................................................ 6
1.2 BACnet® Compatibility.................................................................................................................. 7
1.3 System Outline.............................................................................................................................. 7
2. VRV System Overview........................................................................................................................... 8
2.1 Types of Daikin VRV Systems........................................................................................................ 8
2.2 DIII-Net System and Group Addresses ......................................................................................... 9
2.3 Remote Controller Group and Group Address ............................................................................. 9
2.4 Commanding Mode Change for Heat Recovery and Heat Pump Systems................................. 11
2.5 Changeover Master and Secondary (Non-Master) Indoor Units................................................12
2.6 Indoor Unit Logic ........................................................................................................................12
3. iTM Overview......................................................................................................................................14
3.1 Indoor Unit Management Point ................................................................................................. 14
3.2 Automatic Control ......................................................................................................................16
Part 2. Functional Specifications...............................................................................................................21
1. Introduction ........................................................................................................................................ 21
2. Network Topology ..............................................................................................................................21
2.1 Visualization of Each Device on the BACnet® Network.............................................................. 21
2.2 BACnet® Network Number......................................................................................................... 22
2.3 Device ID (Device Instance Number) ..........................................................................................22
2.4 What is a MAC Address?............................................................................................................. 22
2.5 MAC Address of a Virtual BACnet® Device ................................................................................. 22
3. iTM and BACnet® Server Gateway Logic ............................................................................................23
3.1 BACnet® Virtual Router Function ...............................................................................................23
3.2 iTM BACnet® Server Gateway Point Logic in the iTM.................................................................23
4. VRV System Monitor/Control Objects................................................................................................ 24
4.1 Member Objects......................................................................................................................... 24
4.2 Indoor Unit Device...................................................................................................................... 24
4.3 System Control Device................................................................................................................27
4.4 Restrictions .................................................................................................................................27

5. Properties ........................................................................................................................................... 30
5.1 Device Object Type..................................................................................................................... 30
5.2 System Control Device................................................................................................................32
5.3 Analog Input Object Type ........................................................................................................... 34
5.4 Analog Value Object Type........................................................................................................... 35
5.5 Binary Input Object Typed..........................................................................................................36
5.6 Binary Output Object Type .........................................................................................................37
5.7 Binary Value Object Type ...........................................................................................................38
5.8 Multi-State Input Object Type.................................................................................................... 39
5.9 Multi-State Output Object Type ................................................................................................. 40
5.10 Multi-State Value Object Type ...................................................................................................41
6. Error Response in BACnet® Communication ......................................................................................42
7. Detailed Description of Objects.......................................................................................................... 43
7.1 Specifications Common to All Objects........................................................................................43
7.2 Individual Object Specifications.................................................................................................. 44
7.3 Individual System Control Object Specifications ........................................................................61
8. Report Function .................................................................................................................................. 63
8.1 COV Notification ......................................................................................................................... 63
9. Error Codes ......................................................................................................................................... 64
10. PICS ...................................................................................................................................................66
11. BACnet® Interoperability Building Blocks Supported (BIBBs)........................................................... 70
Part 3. Commissioning Procedure............................................................................................................. 74
1. Site Visit .............................................................................................................................................. 74
1.1 Obtaining Object Information .................................................................................................... 74
2. Foreign Device .................................................................................................................................... 79
2.1 Foreign Device Setting................................................................................................................ 79
2.2 Typically Not Changed Unless Requested by the BMS............................................................... 79
3. BACnet® Point List .............................................................................................................................. 80
What is a point list? ............................................................................................................................ 80
3.1 System Control (one per system) ............................................................................................... 80
3.2 Indoor Unit Points (for each indoor unit) ...................................................................................81
4. Commissioning the BACnet® Server Gateway on the iTM .................................................................81
4.1 The iTM BACnet® Server Gateway Activation ............................................................................82
4.2 CSV Configuration.......................................................................................................................83
5. Connecting the test operation PC and iTM via the cross cable or the hub/switch
using 100BASE-TX straight cable ........................................................................................................89
5.1 Connecting a Test PC to the iTM ................................................................................................89
5.2 Configuring iTM Network Settings..............................................................................................89

5.3 How to configure PC Network Settings ......................................................................................89
5.4 Return the IP address of the Test PC to the Original Address After the Test Operation ........... 90
6. Reference............................................................................................................................................ 91
6.1 Possible Causes for Unconnected iTM and Test Operation PC .................................................. 91
6.2 How to Execute PING..................................................................................................................91
7. Handover to BMS................................................................................................................................92
7.1 CSV File ....................................................................................................................................... 92
7.2 Network Settings ........................................................................................................................92
7.3 Ask the BMS Integrator to Discover the BACnet® Points from the iTM..................................... 92
7.4 Unable to Auto-Discover BACnet® Points .................................................................................. 92
7.5 Final Review................................................................................................................................92
Part 4. Programming Guide....................................................................................................................... 93
1. Typical Requirements ......................................................................................................................... 93
1.1 Typical Indoor Unit Schedule Set by BMS Master Schedule....................................................... 93
2. How to Program.................................................................................................................................. 93
2.1 Setpoints.....................................................................................................................................93
2.2 Setpoint Range Limitation ..........................................................................................................94
2.3 Auto-Changeover Configuration................................................................................................. 94
2.4 Schedule ..................................................................................................................................... 94
2.5 Timed Override...........................................................................................................................94
2.6 Remote Controller Prohibits....................................................................................................... 94
3. Notes................................................................................................................................................... 95
3.1 Indoor Unit EEPROM .................................................................................................................. 95
3.2 Priority Array...............................................................................................................................95
Part 5. Installation Manual ....................................................................................................................... 96
1. Installation ..........................................................................................................................................96
1.1 Understanding theLocation of Terminals and Switches............................................................. 96
1.2 Rear Face .................................................................................................................................... 96
1.3 Front Panel.................................................................................................................................. 97
1.4 Side Face ..................................................................................................................................... 98
1.5 Environmental Conditions ..........................................................................................................98
2. Electrical Wiring.................................................................................................................................. 99
2.1 Removing Wiring Cover from Rear Face.....................................................................................99
2.2 Connecting DIII-Net-Compatible Air Conditioning Equipment...................................................99
2.3 Wiring Specifications ................................................................................................................100

3. Basic Setup of Intelligent Touch Manager........................................................................................ 105
3.1 Setting Backup Battery to ON...................................................................................................105
3.2 Turning On Power Supply to iTM and Air Conditioners ...........................................................106
Appendix A. BACnet® Gateway (DMS502B71) and iTM Protocol Comparison ................................... 107
1. Functions Removed from BACnet® Gateway...............................................................................107
2. Changes from the BACnet® Gateway .......................................................................................... 108
Appendix B. Supported Models and Monitoring Control Items ..........................................................111
Appendix C. iTM Specifications, Dimensions, and System Wiring ....................................................... 113
1. Specifications ...............................................................................................................................113
2. Dimensions...................................................................................................................................113
3. System Configuration and Wiring................................................................................................ 115

Part 1. Overview
6 Design Guide DCM014A51
Part 1. Overview
1. DCM014A51 iTM BACnet® Server Gateway
The intelligent Touch Manager (iTM) is now capable of serving as a BACnet® interface for Building
Management System (BMS) integration. The iTM BACnet® Server Gateway option (DCM014A51) will
provide BMS integrators the ability to monitor and control VRV indoor units via the BACnet®/IP protocol.
The iTM BACnet® Server Gateway option eliminates the need for an additional hardware interface for
the BMS to monitor and control a VRV system. The iTM BACnet® Server Gateway option provides
seamless control-logic integration between the iTM and BMS.
Figure 1. iTM BACnet® Server Gateway
1.1 Features:
• Direct connection on iTM using the BACnet®/IP Protocol.
• BACnet® virtual router function implemented:
» Individual BACnet® device ID assigned to each indoor unit group address.
»Indoor unit group names created in the iTM are visible on the BMS.
• Easy commissioning using CSV file.
»Available objects can be configured for each indoor unit.
• Support Change of Value (COV) notifications to BMS.
• Configurable as a BACnet® foreign device if BBMD exists on a different subnet within BACnet®
network.
• Independent heating and cooling setpoints for occupied and unoccupied periods.
• Individual min/max Setpoint Range Limitation for heat and cool modes.
• The iTM’s auto-changeover, setpoint range limitation, setback, dual setpoint logic, and
schedule can be accessed by the BMS.
The intelligent Touch Manager (hereinafter referred to as "iTM") supports the BACnet® 2004 protocol
(hereinafter referred to as "BACnet® specifications"). The iTM operates as a BACnet® server that
provides BACnet® objects to monitor/operate indoor units connected to the DIII network in response to
requests from a Building Management System (BMS), i.e., BACnet® client.

Part 1. Overview
DCM014A51 Design Guide 7
This document describes the operation for the BACnet® Server Gateway option for the iTM.
1.2 BACnet® Compatibility
• Packaging of the VRV indoor unit objects:
»Compatible with BACnet® (ANSI / ASHRAE-135).
»Compatible with BACnet® / IP (ISO16484-5).
• Conforming to Safety and Electromagnetic Compatibility (EMC) rules and regulations.
1.3 System Outline
1. Typical BACnet® Server Gateway Application:
Figure 2. Typical Daikin VRV System
2. The iTM BACnet® Server Gateway (DCM014A51) software option provides communication
between the VRV system and the BMS. The operation and monitoring of the VRV systems
through BACnet® communication uses the BACnet®/IP protocol.
3. Up to 128 indoor unit management points can be controlled and monitored through the iTM
BACnet® Server Gateway.
4. Up to 7 additional DIII-Net communication systems can be added with optional iTM Plus
Adaptors. The iTM Plus Adaptor is intended for use with the iTM, and shall not be used
independently.

Part 1. Overview
8 Design Guide DCM014A51
2. VRV System Overview
The Daikin VRV system consists of outdoor units, indoor units, zone controllers, centralized controllers,
and BMS interfaces. The customizable Daikin control system is built around the VRV system, and does
not require advanced field engineering (i.e., programming) for the control of the VRV system, except for
field settings configurations. The iTM BACnet® Server Gateway can be used for monitoring, scheduling,
control, and interlock operation. A BMS can be used in conjunction with the Daikin controllers to share
operation workload to reduce project costs.
2.1 Types of Daikin VRV Systems
The VRV system can consist of either a Heat Recovery system, Heat Pump systems, or system that has
a combination of both.
1. Heat Recovery systems can provide simultaneous cooling and heating to each indoor unit
served by the same outdoor unit with use of Branch Selector Boxes (BS Box).
Figure 3. Heat Recovery System
2. Heat Pump systems only allow each outdoor unit and its connected indoor units to operate in
either cooling or heating mode. Multiple Heat Pumps systems can be installed to operate
independently in either cooling or heating mode.
Figure 4. Heat Pump System

Part 1. Overview
DCM014A51 Design Guide 9
2.2 DIII-Net System and Group Addresses
1. The DIII-Net system consists of the following:
a. Up to 10 VRV outdoor units (daisy chained).
b. Up to 128 indoor units.
2. The iTM (central controller) and DIII-Net system consists of the following:
a. Up to 10 VRV outdoor units (daisy chained).
b. Up to 64 indoor unit groups (128 indoor units).
c. Up to 7 iTM Plus Adapters can be connected to a single iTM. Each adapter can contain up to
64 group addresses and 10 outdoor units.
3. When a centralized controller is connected to the DIII-Net system, a unique group address
must be created for each indoor unit to be monitored and controlled by the central controller.
4. Group Address:
a. Indoor units are assigned unique group addresses (up to 64 per DIII-Net system) manually
during the VRV commissioning.
b. Addresses are as follows: 1-00 to 1-15, 2-00 to 2-15, 3-00 to 3-15, 4-00 to 4-15.
c. With the use of the iTM Plus Adapter, up to 8 DIII-Net systems can be connected to a single
iTM. Each DIII-Net system will be assigned a port number with the iTM being port 1. For
example, an indoor unit connected to the iTM will have the complete group address of 1:1-
00. Similarly, each additional system will be assigned a port number 2 to 8 (2:1-00, 3:1-00,
etc.).
2.3 Remote Controller Group and Group Address
1. A remote control group consists of 1 -16 indoor units connected (via P1P2 daisy chain) to the
same remote controller. The indoor unit group allows for a maximum of 2 remote controllers
to be connected to the same remote controller group. It is not required to have a remote
controller connected to an indoor unit. If no remote controllers are used there should be a
centralized method for monitoring and controlling the indoor units.
2. Assigning a group address to a single indoor unit (typical configuration):
* F1F2 = DIII-Net ** P1P2 = Remote Controller line
Figure 5. Assigning Group Address to a Single Indoor Unit

Part 1. Overview
10 Design Guide DCM014A51
3. Assigning one group address to a remote controller group:
Figure 6. Assigning One Group Address to a Remote Controller Group
4. Assigning a group address to each indoor unit in a remote controller group:
Figure 7. Assigning a Group Address to Each Indoor Unit in a Remote Controller Group
Note: As shown in the figures above, a remote controller group consists of several
indoor units wired to the same remote controller. A remote controller group consists of
1-16 indoor units that can be started or stopped simultaneously. For units without a
remote controller, each unit is treated as a group.

Part 1. Overview
DCM014A51 Design Guide 11
2.4 Commanding Mode Change for Heat Recovery and Heat Pump Systems
What is a Changeover Master?
1. When the VRV contractor has commissioned a Heat Pump system, an indoor unit can be
nominated as the changeover master. This allows the nominated unit to change the mode of
operation for all units connected to the same outdoor unit.
Figure 8. Heat Pump System
2. A Heat Recovery system can utilize BS Boxes to provide simultaneous heating and cooling for
each zone.
Figure 9. Heat Recovery System
3. Every unit or group of units connected to a BS Box port can either be in cooling or heating
mode, i.e., units connected to the same BS Box port operate as a mini Heat Pump system.

Part 1. Overview
12 Design Guide DCM014A51
2.5 Changeover Master and Secondary (Non-Master) Indoor Units
1. Cool and heat modes are only available for selection on the cool/heat changeover master
indoor unit. The following table indicates the available operating modes for secondary indoor
units in the system based on the selected mode of the master indoor unit.
When the master
indoor unit is set to:
Secondary indoor units in the
system can be set to:
Cool Dry Heat Fan
Cool mode
•
•
•
Dry mode
•
•
•
Heat mode
•
•
Fan mode
•
2.6 Indoor Unit Logic
1. The indoor unit contains control logic to maintain room temperature by adjusting the
refrigerant flow and has the following data points:
a. Unit ON/OFF.
b. Operation Mode – Cool, Heat, Fan, Dry, Auto (Auto mode is not recommended as it can
create large temperature differentials between mode changes).
c. Setpoint – 60oF to 90oF, 1oF basis (16oC to 32oC, 0.1oC basis).
d. Room Temperature (read only).
e. Fan Speed – L, ML, M, MH, H, Auto (depends on indoor unit type).
f. Airflow Direction (if the indoor unit has louvers).
g. Alarm Status (read only).
h. Malfunction Code (read only).
2. Indoor Unit Sequence of Operation
a. During the cooling thermo-on (call for cooling) period, the indoor unit fan will operate based
upon the fan setting from the local controller, iTM, or BMS.
b. During the cooling thermo-off (cooling satisfied) period, the fan will continue to operate
based on the setting from the local controller, iTM, or BMS fan speed setting. However, the
fan can be turned OFF during the thermo-off period with a field setting (depends on the
indoor unit type). Also, the fan should not be OFF when an indoor unit receives outside air.
c. During the heating thermo-on (call for heating) period, the indoor unit fan will operate
based on the fan setting from the local controller, iTM, or BMS.
d. During the heating thermo-off (heating satisfied) period, the fan will continue to operate in
LL (Low Low) speed (default). The fan can be set to ON (H, MH, M, ML, L), LL or completely
OFF with a field setting (depends on the indoor unit type). However, the fan should not be
OFF when an indoor unit receives outside air.

Part 1. Overview
DCM014A51 Design Guide 13
3. Dry Mode
a. When selected, the setpoint is based on the room temperature as not to over cool.
1. Setpoint = Return Air (when the Return Air ≤ 75°F).
2. Setpoint = Return Air – 1°F (when the Return Air > 76°F).
b. The current setpoint is not displayed on the local controller, iTM, or the BACnet® Server
setpoint present value during Dry mode.
c. In Dry mode (or Fan mode), the BMS can write the cooling and heating setpoints to the iTM,
and are set to the IDU management point in the iTM. However, the cooling and heating
setpoints are not sent to the indoor unit.
4. Room Temperature Sensing
a. The room temperature can be measured by the following:
1. Indoor unit return air sensor (depending on indoor unit model).
2. Remote temperature sensor (KRCS01-1B/4B).
3. Sensor in the BRC1E73 (local remote controller).
b. The sensing local method depends on the indoor unit configuration (field setting).
c. The BMS cannot send the room temperature to the indoor unit due to the fact that the
room temperature is a read only point for the BMS.

Part 1. Overview
14 Design Guide DCM014A51
3. iTM Overview
3.1 Indoor Unit Management Point
1. The iTM manages the indoor unit groups as an Indoor Unit Management Point only when a
group address is assigned (see 2.3 Remote Controller Group and Group Address) to an indoor
unit(s).
One (1) indoor unit management point consists of the following on the iTM:
Function Monitor Control
On/Off X X
Operation Mode X X
Occ Cooling/Heating Setpoint X X
Unocc Cool/Heat Setpoint X X
Fan Speed X X
Vane Position X X
Remote Controller Prohibit (On/Off, Mode, Setpoint) X
Room Temperature X
Setpoint Range Limitation (Cool/Heat Min/Max) X
Error Status X
Malfunction Code X
Override Timer X
Setpoint Tracking X
Minimum Setpoint Differential X
2. Setpoints
a. Independent cool and heat dual setpoints in the occupied period. Single setpoint mode is
available with 0oF min setpoint differential and setpoint tracking enabled.
b. Occupied setpoint range for cooling and heating are configurable by Setpoint Range
Limitation within 60oF – 90oF as a default. The cooling setpoint cannot be set lower than the
heating setpoint and the heating setpoint cannot be set higher than the cooling setpoint.
c. Minimum Cool/Heat Setpoint Differential refers to the difference between the cooling and
heating setpoint values. The differential can be set between 0oF – 7oF.
d. Setpoint tracking is used to lock in the Min. Setpoint Differential for cooling and heating to a
fixed value.
e. The setback setpoints (cooling and heating) in the unoccupied period are adjustable
between 50oF – 95oF.
f. The setback setpoints can only be set outside of the occupied setpoint range with a 2oF
differential. The setback (unoccupied) setpoint will reduce the occupied setpoint range
automatically to maintain a 2oF fixed differential from the highest (cooling) and lowest
(heating) possible occupied setpoints.

Part 1. Overview
DCM014A51 Design Guide 15
Figure 10. Relationship between Setpoints, Setback, and Setpoint Range Limitation
3. Setback
a. The Setback function keeps the room temperature at a moderate level with the setback
setpoints when the indoor unit is off (when the room is unoccupied). The indoor unit only
turns on if the room temperature rises to meet the Cool Setback Setpoint in cooling mode,
or if the room temperature falls to meet the Heat Setback Setpoint in heating mode. Once
the room temperature has recovered and the guard timer has expired, the indoor unit is
turned off.
b. A guard timer keeps the indoor unit on for at least 30 minutes after the Setback function
turns on the indoor unit.
c. If the indoor unit is set to Fan or Dry mode, the setback function will not work.
d. The iTM setback provides independent setback setpoints for cooling and heating.
e. By default the setback setpoints are disabled and can be enabled by the schedule, interlock,
and setting features.
1. The default setback setpoint for cooling is 80oF (configurable).
2. The default setback setpoint for heating is 64oF (configurable).
3. Independent Setback Recovery Temp (hysteresis) for cooling (-4oF default) and heating
(+4oF default). Configurable from 2oF to 10oF.
f. Setback Control Logic
1. Room temperature and setback setpoint are evaluated every five minutes for each indoor
unit.
2. If the indoor unit is turned on by the iTM manually (or by the Schedule function), the
normal operation is maintained, i.e., the indoor unit maintains the room temperature
from the setpoint.
3. When the Setback function turns on the indoor unit (unless it is turned off by the iTM
manually, by the Schedule function, or by a remote controller), the Setback function
maintains the room temperature below (or above) the setback setpoint.

Part 1. Overview
16 Design Guide DCM014A51
4. Timer Extension
a. The Timer Extension is used to turn the indoor unit off (after a specified time has expired)
when it is turned on manually by the iTM or remote controller during unoccupied hours. It
can be set for 30, 60, 90, 120 (default), 150, or 180 minutes. The Timer Extension must be
enabled to operate during the unoccupied period.
b. Timer Extension function will not turn off an indoor unit that was turned on by the Setback
function.
3.2 Automatic Control
1. Scheduling
a. Independent cool and heat setpoints and independent setback setpoints allow for one
schedule to be set to run year round.
Figure 11. Year round setpoint schedule
b. Up to 100 schedule programs can be created.
c. A 7 day, 5+2 (Weekday + Weekend), 5+1+1 (Weekday + Saturday + Sunday) and 1 (Everyday)
schedules can be created in the iTM.
d. Up to 20 events can be registered each day.
e. Special Day (such as holiday) events can be created:
1. Up to 5 special day patterns can be registered.
2. Up to 20 events can be registered each day.
3. Events can be set by calendar date or by week and day of the month (Ex. July 4th or 1st
Monday in September).
f. The iTM schedule can provide an Optimum Start function to insure the room temperature
achieves setpoint at the scheduled event time. Optimum Start calculates the time when the
target indoor units turn on, according to the room temperature and the setpoint for the
current operation mode. Optimum Start evaluates and adjusts the turn-on time
appropriately. The schedule and Optimum Start feature can only be set via the iTM schedule
function and cannot be configured by the BMS.

Part 1. Overview
DCM014A51 Design Guide 17
g. The Daylight Savings Time (DST) setting automatically adjusts the iTM clock to insure
scheduled operation times are met.
Figure 12. Typical Weekday Office Schedule
2. iTM Auto-Changeover
a. Using the advanced auto-changeover functions in the iTM, the BMS programming time is
significantly reduced. Automatic changeover is available for both Heat Pump and Heat
Recovery systems. The changeover is automatically controlled to occur in the following two
cases:
Case 1: Changeover at the primary changeover temperature after the guard timer expires.
1. The changeover is evaluated by how much the room temperature has deviated from the
cooling or heating setpoint. For example, when the room temperature exceeds the
primary changeover deadband from the cooling setpoint, iTM initiates a change from
heating mode to cooling mode.
2. By default, the primary changeover setpoint is 1°F above the cooling setpoint or 1°F
below heating setpoint, which are configurable between 1°F – 4°F.
3. The guard timer can be set to 15, 30, or 60 (default) minutes.
a. The initiation of the guard timer is built in to help prevent frequent changeovers
which may cause energy loss.
b. When the setpoint is changed manually or by the schedule, the guard timer is not
active.

Part 1. Overview
18 Design Guide DCM014A51
Figure 13. Cool/Heat Changeover Logic
Case 2: Changeover at the secondary changeover temperature.
1. By default, the secondary changeover temperature is 1°F above the primary changeover
temperature for cooling, or 1°F below the primary changeover temperature for heating,
which is configurable between 1°F – 4°F.
2. Case 2 will happen while the guard time is active in Case 1.
3. The iTM auto-changeover is applicable to both Heat Pump and Heat Recovery systems.
a. The iTM provides four changeover methods to meet a variety of expectations in a
project. Fixed, Individual, Average, or Vote methods can be specified in the
changeover group with targeted indoor units, as well as Primary/Secondary
Changeover deadbands.
1. Fixed Method:
a. Changeover is evaluated with the representative indoor unit.
b. Changeover affects all indoor units.
c. Good method for prioritizing the representative indoor unit for the Heat Pump
system (or multiple units on the same port of the BS Box in Heat Recovery
system).
Figure 14. Fixed Method

Part 1. Overview
DCM014A51 Design Guide 19
2. Individual Method:
a. Changeover is evaluated by, and affects, each indoor unit individually.
b. Used in application with the Heat Recovery system.
Figure 15. Individual Method
3. Average Method:
a. Changeover is evaluated based on the average of the room temperature and
average setpoints in the changeover group.
b. A weight (0-3) can be added to each indoor unit demand in the changeover
group. The default is 1.
c. Changeover affects all indoor units in the changeover group.
d. Used in applications with Heat Pump systems (or multiple units on the same
port of the BS Box in the Heat Recovery system).
Figure 16. Average Method
4. Vote Method:
a. Changeover is evaluated based on the total cooling demand and total heating
demand. If the total cooling demand is greater than the heating demand, the
iTM changes the indoor units in the changeover group to cool mode.
b. When the changeover group is in cooling mode, the total cooling demand will
decrease; at that point, the total heating demand may become greater than the
cooling demand and change the mode to heating (a guard timer applies).

Part 1. Overview
20 Design Guide DCM014A51
c. The setpoints can be different in each indoor unit within the changeover group.
The demand is calculated based on the setpoints in comparison to room
temperature for each indoor unit. The demand within the Primary Changeover
deadband (PCd) is considered as no demand.
d. A good method for Heat Pump systems (or multiple units on the same port of
the BS Box in Heat Recovery system) as a pseudo-simultaneous cooling and
heating operation.
e. A weight (0-3) can be added to each indoor unit demand in the changeover
group. The default is 1.
f. An option for heating override can be applied if there is an indoor unit which
the heating demand exceeds [H_SP- (PCd + SCd)].
Figure 17. Vote Method