Daikin McQuay ED 15117 User manual

Engineering Data ED 15117
Group: Controls
Part Number: ED 15117
Date: April 2010
Supersedes: New
MagnitudeTM Chiller Unit Controller
Protocol Information
BACnet®Networks (MS/TP, IP, Ethernet)
LONWORKS®Networks
Daikin McQuay Magnitude™Magnetic Bearing Centrifugal Chiller, Single-
Compressor Model WME
© 2010 McQuay International

2 ED 15117
Table of Contents
BACnet®Networks (MS/TP, IP, Ethernet)
LONWORKS®Networks .............................. 1
Table of Contents ..................................... 2
REVISION HISTORY ........................................4
SOFTWARE REVISION .....................................4
REFERENCE DOCUMENTS...............................4
NOTICE...........................................................4
LIMITED WARRANTY .....................................4
Introduction ............................................... 5
UNIT CONTROLLER DATA POINTS..................5
PROTOCOL DEFINITIONS.................................5
Basic Protocol Information ........................ 6
SETTING UNIT CONTROLLER
COMMUNICATIONS PARAMETERS...................6
BACNET NETWORKS .....................................6
MAGNITUDE CHILLER UNIT CONTROLLER
DEVICE OBJECT..............................................8
Network Considerations.......................... 11
ACCESS TO PROPERTIES ...............................11
BACNET NETWORKS ...................................11
BACNET DEVICE MANAGEMENT.................13
Configuring the Unit Controller................ 15
LONWORKS NETWORKS...............................15
Typical Application: Minimum Integration 20
SET UP THE UNIT CONTROLLER FOR NETWORK
CONTROL .....................................................20
DISPLAY IMPORTANT DATA POINTS.............20
ALARMS.......................................................21
Protocol Point Summary - BACnet.......... 22
Protocol Point Summary - LONWORKS .... 25
NETWORK OUTPUT VARIABLES ...................25
NETWORK INPUT VARIABLES.......................26
NETWORK CONFIGURATION PARAMETERS...27
Detailed Data Point Information .............. 28
ACTIVE SETPOINT ........................................28
ACTUAL CAPACITY ......................................28
ALARM DIGITAL OUTPUT.............................29
APPLICATION VERSION ................................29
CAPACITY LIMIT ..........................................29
ACTIVE CAPACITY LIMIT OUTPUT ...............30
CAPACITY LIMIT SETPOINT -NETWORK.......30
CHILLER ENABLE.........................................31
CHILLER ENABLE OUTPUT ...........................31
CHILLER ENABLE SETPOINT.........................32
CHILLER CAPACITY LIMITED .......................32
CHILLER LOCAL/NETWORK .........................34
CHILLER LOCATION .....................................34
CHILLER MODE............................................35
CHILLER MODE OUTPUT..............................35
CHILLER MODE SETPOINT -NETWORK ........36
CHILLER MODEL..........................................36
CHILLER ON OFF..........................................36
CHILLER STATUS .........................................37
CLEAR ALARM NETWORK............................38
COMPRESSOR AVERAGE CURRENT ..............40
COMPRESSOR AVERAGE VOLTAGE ..............40
COMPRESSOR DISCHARGE REFRIGERANT
PRESSURE.....................................................40
COMPRESSOR DISCHARGE REFRIGERANT
TEMPERATURE .............................................41
COMPRESSOR DISCHARGE SATURATED
REFRIGERANT TEMPERATURE......................41
COMPRESSOR PERCENT RLA.......................42
COMPRESSOR POWER...................................42
COMPRESSOR RUN HOURS...........................42
COMPRESSOR SELECT ..................................43
COMPRESSOR STARTS ..................................43
COMPRESSOR SUCTION SATURATED
REFRIGERANT TEMPERATURE......................44
COMPRESSOR SUCTION REFRIGERANT
PRESSURE.....................................................44
COMPRESSOR SUCTION REFRIGERANT
TEMPERATURE .............................................45
CONDENSER ENTERING WATER
TEMPERATURE .............................................45
CONDENSER FLOW SWITCH STATUS ............45
CONDENSER LEAVING WATER TEMPERATURE
.....................................................................46
CONDENSER PUMP RUN HOURS ...................46
CONDENSER REFRIGERANT PRESSURE.........47
CONDENSER SATURATED REFRIGERANT
TEMPERATURE .............................................47
CONDENSER WATER FLOW RATE ................47
CONDENSER PUMP STATUS..........................48
COOL SETPOINT -NETWORK........................49
COOL SETPOINT ...........................................49
CURRENT DATE &TIME...............................49
DEFAULT VALUES........................................50
EVAPORATOR ENTERING WATER
TEMPERATURE .............................................50
EVAPORATOR FLOW SWITCH STATUS..........50

ED15117 3
EVAPORATOR LEAVING WATER
TEMPERATURE .............................................51
EVAPORATOR PUMP RUN HOURS .................52
EVAPORATOR PUMP STATUS........................52
EVAPORATOR WATER FLOW RATE ..............53
FILE DIRECTORY ADDRESS ..........................53
HEAT RECOVERY ENTERING WATER
TEMPERATURE .............................................53
HEAT RECOVERY LEAVING WATER
TEMPERATURE .............................................54
HEAT SETPOINT -NETWORK ........................54
HEAT SETPOINT............................................55
ICE SETPOINT -NETWORK............................55
ICE SETPOINT ...............................................55
MAXIMUM SEND TIME .................................56
MINIMUM SEND TIME ..................................56
OBJECT STATUS ...........................................57
OBJECT REQUEST.........................................58
OUTDOOR AIR TEMPERATURE......................59
PUMP SELECT...............................................59
RECEIVE HEARTBEAT...................................60
RUN ENABLED..............................................60
SOFTWARE IDENTIFICATION (MAJOR
VERSION) .....................................................61
SOFTWARE IDENTIFICATION (MINOR VERSION)
.....................................................................61
UNITS...........................................................61
Alarms-BACnet........................................63
ALARM CLASSES..........................................63
BACNET ALARM HANDLING .......................63
Clearing Alarms-BACnet .........................65
BACNET ALARM MESSAGES .......................65
Alarms-LONWORKS ..................................67
CURRENT ALARM.........................................67
Clearing Alarms - LONWORKS ..................68
LONWORKS ALARM MESSAGES...................68
Appendix A: Protocol Implementation
Conformance Statement (PICS)..............70
BACNET PROTOCOL IMPLEMENTATION
CONFORMANCE STATEMENT........................70
PRODUCT DESCRIPTION................................70
BACNET STANDARDIZED DEVICE PROFILE..70
BACNET INTEROPERABILITY BUILDING
BLOCKS (BIBBS)SUPPORTED......................70
STANDARD OBJECT TYPES SUPPORTED........72
DATA LINK LAYER OPTIONS........................74
SEGMENTATION CAPABILITY .......................74
DEVICE ADDRESS BINDING..........................74
NETWORKING OPTIONS................................74
CHARACTER SETS SUPPORTED.....................74
NON-BACNET EQUIPMENT/NETWORK(S)
SUPPORT ......................................................74
Index of Detailed Point Information .........75

4 ED 15117
Revision History
ED15117 April 2010 Preliminary release.
Software Revision
This edition documents all versions of the standard Magnitude Chiller Unit Controller software and all
subsequent revisions until otherwise indicated. You can determine the revision of the application
software from the display. The version is located on the Service screen. BACnet can also read the
software revision by reading the Application_Software_Version property of the Device Object.
Reference Documents
Company Number Title Source
McQuay International OM 1034 MagnitudeFrictionless Centrifugal Chiller Operation and
Maintenance Manual www.mcquay.com
McQuay International IM 963 Magnitude Frictionless Centrifugal Chiller, BACnet
Communication Module (MSTP, IP/Ethernet) Installation
Manual www.mcquay.com
McQuay International IM 965 Magnitude Frictionless Centrifugal Chiller, LONWORKS
Communication Module Installation Manual www.mcquay.com
American Society of
Heating, Refrigerating and
Air-Conditioning Engineers
ANSI/
ASHRAE 135-
2004
BACnet® A Data Communication Protocol for Building
Automation and Control Networks www.ashrae.org
LonMark Interoperability
Association
078-0120-01G LonMark® Layers 1-6 Interoperability Guidelines, Version 3.4 www.lonmark.org
LonMark Interoperability
Association 078-0120-01G LonMark Application Layer Interoperability Guidelines, Version 3.4 www.lonmark.org
LonMark Interoperability
Association 8040_10 LonMark Functional Profile: Chiller, Version 1.0 www.lonmark.org
Echelon Corporation 078-0156-01G LONWORKS FTT-10A Free Topology Transceiver Users Guide www.echelon.com
Notice
© 2010 McQuay International, Minneapolis MN. All rights reserved throughout the world
McQuay International reserves the right to change any information contained herein without prior
notice. The user is responsible for determining whether this product is appropriate for his or her
application.
The following are trademarks or registered trademarks of their respective companies: BACnet
from American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. Echelon,
LONWORKS, LONMARK, and LonTalk from Echelon Corporation, Windows from Microsoft
Corporation, and McQuay, Daikin McQuay, and Magnitude from McQuay International.
Limited Warranty
Consult your local McQuay Representative for warranty details. Refer to Form 933-430285Y. To find
your local McQuay Representative, go to www.mcquay.com.

ED15117 5
Introduction
This document contains the necessary information you need to incorporate a Daikin McQuay
Magnitude™ Chiller Unit Controller into a building automation system (BAS). It lists all BACnet®
properties, LONWORKS®variables, and corresponding Magnitude Chiller Unit Controller data points. It
also contains the BACnet Protocol Implementation Conformance Statement (PICS). BACnet and
LONWORKS terms are not defined. Refer to the respective specifications for definitions and details.
Unit Controller Data Points
The Magnitude Chiller Unit Controller contains data points or unit variables that are accessible from
three user interfaces: the unit controller OITS panel, a BACnet network (BACnet/IP, Ethernet, or
MS/TP), or a LONWORKS network. Not all points are accessible from each interface. This manual lists
all important data points and the corresponding path for each applicable interface. Refer to OM 1034
(available on www.mcquay.com) for display details. This document contains the network details
necessary to incorporate the Magnitude Chiller Unit Controller into the network.
Protocol Definitions
The Magnitude Chiller Unit Controller can be configured in either an interoperable BACnet or
LONWORKS network. The unit controller must have the corresponding communication module installed
for network integration (see Reference Document section for corresponding part numbers). There are
three communication modules: BACnet IP/Ethernet, BACnet MS/TP (Master/Slave Token Passing),
and LONWORKS.
BACnet Protocol
BACnet is a standard communication protocol for Building Automation and Control Networks
developed by the American National Standards Institute (ANSI) and American Society of Heating,
Refrigeration and Air-conditioning Engineers (ASHRAE) specified in ANSI/ASHRAE standard 135-
2004. It addresses all aspects of the various systems that are applied to building control systems.
BACnet provides the communication infrastructure needed to integrate products manufactured by
different vendors and to integrate building services that are now independent.
The Magnitude Chiller Unit Controller is tested according to the BACnet Testing Laboratory (BTL)
Test Plan. It is designed to meet the requirements of the BACnet Standard (ANSI/ASHRAE 135-2004)
as stated in the Protocol Implementation and Conformance Statement (PICS). However, it is not BTL
listed. The PICS are located at the end of this manual or the separate PICS document, ED 15119
(available on www.mcquay.com.)
LONWORKS Networks
A control network specification for information exchange built upon the use of the LonTalk®protocol
for transmitting data developed by the Echelon®Corporation.
LonTalk Protocol
A protocol developed and owned by the Echelon Corporation. It describes how information should be
transmitted between devices on a control network.
LonMark®Certification
LonMark certification is an official acknowledgement by the LonMark Interoperability Association that
a product communicates using the LonTalk protocol and transmits and receives data per a standard
LonMark functional profile. The LONWORKS communication module is LonMark 3.4 certified in
accordance with the Chiller functional profile.

6 ED 15117
Basic Protocol Information
Setting Unit Controller Communications Parameters
There are 12 communication parameters involved in setting up the unit controller for proper
communication with the three communication module options (BACnet IP/Ethernet, BACnet MS/TP,
LONWORKS). These parameters are set differently depending on which communication module is
ordered and shipped with the unit. The table below lists the three possible sets of default parameter
settings. Not all the parameters apply to all the module options. All parameters, except for Receive
Heartbeat, are configurable via the unit controller display. The boldface settings can only be
configured via the unit controller OITS (Operator Interface Touch Screen). See Magnitude
Chiller Unit Controller Operation Manual, OM 1034, for details. The items in parenthesis indicate
whether the parameter is Read-Only (R) or Read/Write (W) from the BACnet network.
Communication Parameter Settings
Parameter Name BACnet IP BACnet MS/TP BACnet Ethernet LONWORKS
IP Address 172.15.5.82N/A N/A N/A
IP Subnet Mask 255.255.255.0 N/A N/A N/A
Default Gateway
Address “None” N/A N/A N/A
UDP Port 47808 N/A N/A N/A
MSTP MAC Address N/A 1 N/A N/A
MSTP Baud Rate N/A 38400 N/A N/A
Device Instance Number
(W) 3000330003N/A N/A
Max APDU Length (R) 1024 480 1476 N/A
Device Object Name (W) Magnitude3Magnitude3Magnitude3N/A
Max Master (W) N/A 127 N/A N/A
Max Info Frames (W) N/A 5 N/A N/A
APDU Retries (W) 3 3 N/A N/A
APDU Timeout (W) 3000 3000 N/A N/A
Receive Heartbeat1N/A N/A N/A 0Sec
1. All parameters, except for Receive Heartbeat, are configurable via the OITS panel.
2. If the IP Address is set to 0.0.0.0 from the unit controller OITS panel or through the network,
DHCP addressing will be enabled and the IP address will be requested from the network DHCP
server.
3. Device value must be unique on the BACnet network.
BACnet Networks
Compatibility
The Magnitude Chiller Unit Controller is tested according to the BACnet Testing Laboratory (BTL)
Test Plan. It is designed to meet the requirements of the BACnet Standard (ANSI/ASHRAE 135-2004)
as stated in the Protocol Implementation and Conformance Statement (PICS). However, it is not BTL
listed. The PICS is located at the end of this manual or the separate PICS document, ED 15119
(available on www.mcquay.com.)
BACnet Objects
Magnitude Chiller Unit Controllers incorporate standard BACnet object types (i.e., object types defined
in the BACnet Standard) that conform to the BACnet Standard. Each object has properties that control
unit variables or data points. Some object types occur more than once in the Magnitude Chiller Unit
Controller; each occurrence or instance has different properties and controls different unit variables or
data points. Each instance is designated with a unique instance index. Some properties can be adjusted

ED15117 7
(read/write properties, e.g., setpoints) from the network and others can only be interrogated (read-only
properties, e.g., status information).
Each data point accessible from a BACnet network is described with a table that gives the Object
Identifier, Property Identifier, Full BACnet Reference or path, and the Name enumeration of the
property.
Example of BACnet Data Point
Object Identifier Property Identifier
Object Type Type Enumeration Instance Property Name Property Enumeration
Binary Output 4 5 Present Value 85
Object Name
AlarmDigitalOutput
Property Values
0 = No Alarm
1 = Alarm
Object Identifier
Object Identifiers are each designated with an Object type as defined in the BACnet specification. The
first column of the data point definition gives the object type. This object happens to be Alarm Digital
Output. The object identifier is a property of the object that you can read from the object. The name of
the property is “Object_Identifier” and the property identifier is 75.
Each object in the unit controller has a unique identifier. BACnet object identifiers are two-part
numbers of BACnet Object Identifier data type. The first part identifies the object type (the first 10 bits
of the 32-bit BACnet Object Identifier [See ANSI/ASHRAE 135-2004 BACnet A Data
Communication Protocol for Building Automation and Control Networks]). The first column of the
data point definition gives the object type. The second part identifies the instances of that particular
object type (the last 22 bits of the 32-bit BACnet Object Identifier).
The object identifier is shown in the data points listing as two numbers. The first number is shown in
the Type ID column and designates the Object type enumeration. The second number is shown in the
Instance column and designates the instance of that particular object type.
The object identifier is a property of the object that you can read from the object code. The name of the
property is “Object_Identifier” and the property identifier is 75. The ASHRAE BACnet specification
reserves the first 128 numbers for ASHRAE defined objects. Manufacturers may define additional
object types and assign a number above 127 as long as they conform to the requirements of the
ASHRAE BACnet specification.
Each object also has a name. Object Names are character strings. The object name is a property of the
object that you can read from the object. The name of the property is “Object_Name” and the property
identifier is 77.
Objects are sometimes referred to as an Object Type and Instance Number as they are in the BACnet
specification. The example object above would be: Binary Output, Instance 5.
Property Identifier
Each object has a number of properties or attributes. Each property has a unique identifier of BACnet
Property Identifier data type. Property identifiers are an enumerated set; a number identifies each
member. The Property Identifier enumeration number is shown in the Property ID column. In the
example above the property identifier is 85.

Property Name
Each property also has a unique name. Property names are character strings and shown in the Property
Name column. In the example above the property name is Present Value.
Object Name
The Object Name is the name of the object in the device. Object Names must be unique within each
BACnet device. In the example above the object name is AlarmDigitalOutput.
Enumerated Values
Some properties are standard data types and some are enumerated sets. If the property value is an
enumerated set, all enumerated values and corresponding meaning are given in the Enumeration
column of the data point listing.
Magnitude Chiller Unit Controller Device Object
Each BACnet-compatible device can only have a single BACnet Device Object.
Device Object Identifier
The Magnitude Chiller Unit Controller Device Object Identifier uniquely specifies the unit within the
network. The device object type for all devices is fixed by ASHRAE at 8. Therefore the device object
instance number must be unique. The device object instance will be read from a parameter in the
Magnitude Chiller Unit Controller during the BACnet communication module’s initialization phase.
The BACnet communication module continues to poll the device object instance parameter during run-
time. If the device object instance is changed at the controller during run-time, the update will be
automatically applied to the BACnet communication module as soon as the change is received. The
allowable range of values for the device object instance will be 0 to 4194302. (The value 4194303 is
reserved by BTL for reading a device’s object id.) If a value greater than 4194302 is read from the
controller, the following default value will be used:
Default device object instance: 3000 + address*
*Address = the last two octets of the MAC Address
For example:
BACnet MS/TP: 3023
BACnet Ethernet: 10312 (3000 + F75A)
BACnet/IP: CDB (3000 + 0123)
The device object identifier can be read from the unit controller. The name of the property is
“Object_Identifier” and the property identifier is 75. Changing the device object ID may affect the
operation of other BACnet devices on the network that have previously discovered the device. The
object instance number can be changed via the unit controller OITS panel.
!CAUTION
If another device in the network already has this object identifier (instance number), you must change the instance number of one
device object, so that all devices in the network have a unique device identifier.
Device Object Name
The Device Object Name uniquely specifies a device in the network. It must be unique in the network.
The device object name will be read from a parameter in the Magnitude Chiller Unit Controller during
the BACnet communication module’s initialization phase. The BACnet communication module
continues to poll the device object name parameter during run-time. If the device object name is
changed at the controller during runtime, the update will be automatically applied to the BACnet
8 ED 15117

ED15117 9
communication module as soon as the change is received. The allowable range of characters for the
device object name will be 1 to 31 characters. If an empty string is read from the controller, the
following default name will be used:
Default device object name: MTE Chiller UCA - address*
*Address = the MAC Address
For example:
BACnet MS/TP: MTE Chiller UCA-23
BACnet Ethernet and BACnet/IP: MTE Chiller UCA-0-176-208-13-247-90
Note: If the constructed name is longer than 31 characters, the numeric portion of the name will be
shortened to fit the name into the 31 character limit.
The Device Object name is also available to the network in the device. The property name is
“Object_Name” and property identifier is 77. Changing the device object name may affect the
operation of other BACnet devices on the network that have previously discovered the device. The
object name can be changed via the unit controller OITS panel.
Device Object Properties
The device object contains many other informative properties as shown in Table 1. Items in bold are
configurable via the BACnet network.
Table 1. Magnitude Chiller Unit Controller Device Object Properties
Property Identifier Default Value Data Type
Object Identifier 75 Device, variable BACnetObjectIdentifier
Object Name 77 Magnitude Character String
Object Type 79 8 BACnetObjectType
System Status 112 BACnetDeviceStatus
Vendor Name 121 McQuay International Character String
Vendor Identifier 120 3 Unsigned 16
Model Name 70 WME Character String
Firmware Revision 44 variable Character String
Application Software Version 12 variable Character String
Location 58 Character String
Description 28 McQuay Chiller Character String
Protocol Version 98 1 Unsigned
Protocol Revision 139 4 Unsigned
Protocol Services Supported 97 readProperty, readPropertyMultiple,
writeProperty,
writePropertyMultiple,
deviceCommunicationControl,
timeSynchronization, who-Has,
who-Is, utcTimeSyncronization,
BACnetServicesSupported

10 ED 15117
Property Identifier Default Value Data Type
reinitializeDevice
Protocol Object Types Supported196 AI, AO, AV, BI, BO, BV, Device,
MSI, MSO, MSV
BACnetObjectTypesSupported
Object List 76 Sequence of BACnetObjectIdentifer
Max APDU Length Accepted 62 1024 (IP) / 480 (MS/TP) Unsigned 16
Segmentation Supported 107 None BACnetSegmentation
APDU Timeout 11 3000 Unsigned
Number of APDU Retries 73 3 Unsigned
Max Master 64 127 (Range: 1 .. 127) Unsigned
Max Info Frames 63 5 (Range: 1.. 5) Unsigned
Device Address Binding 30 Sequence of BACnetAddressBinding
Database Revision 115 1 Unsigned
Local Time257 variable (read from the controller) Time
Local Date256 variable (read from the controller) Date
UTC Offset 119 0 (Range: –720 .. 720) Integer
Daylight Savings Status 24 0 (False) Boolean
1. While the Magnitude Chiller Unit Controller supports all shown object types, not all object types are used. See the Object List for
details.
2. The device properties will be read-only. The controller values are writable from BACnet via the BACnet TimeSynchronization
services.

ED15117 11
Network Considerations
Access to Properties
Object properties are accessible from the network by specifying the device object identifier, object
identifier, and the property identifier. To access a property, you must specify the object identifier
including the device object identifier or the object name including the device object name and the
property identifier.
BACnet Networks
The BACnet communication module supports three separate BACnet data link layers:
BACnet MS/TP
BACnet Ethernet
BACnet/IP
Only one data link layer may be used at one time.
During initialization, the BACnet communication module reads a parameter in the Magnitude Chiller
Unit Controller to select the data link layer. If the value read is not one of the supported BACnet data
link layers, the BACnet communication module initialization loops in this phase of the initialization
until a supported BACnet data link layer value is read from the unit controller. The BACnet
communication module’s active data link layer may not be changed at run-time. If the unit controller
parameter is changed during run-time, the BACnet communication module requires a reset in order to
re-initialize with the new data link layer selection.
The different data link layers have different parameters. All parameters that require configuration are
read from the unit controller by the BACnet communication module via the unit controller OITS panel.
The BACnet communication module reads only those parameters relevant to the selected data link
layer. During initialization, the BACnet communication module must read a complete set of valid
parameters for the BACnet network layer and selected data link layer before proceeding to build a set
of BACnet objects for the device.
BACnet Ethernet Communications Parameters
None of the Ethernet Data Link Layer or Physical layer parameters require configuration.
BACnet/IP Communications Parameters
The key parameters for setting up BACnet/IP are described in the following sub-sections. The
parameters are accessible and configurable via the unit controller OITS panel. They are not accessible
from the BACnet network.
IP Address
The IP address is read from a parameter in the Magnitude Chiller Unit Controller during the BACnet
communication module’s initialization phase. The BACnet communication module can be configured
for Dynamic Host Configuration Protocol (DHCP) addressing by setting the IP Address to 0.0.0.0
using the unit controller OITS panel. The BACnet communication module continues to poll the IP
address parameter during run-time. If the IP address is changed at the unit controller during run-time,
the update is automatically applied to the BACnet communication module as soon as the change is
received. The validity of the IP address is verified against the Subnet Mask. If the address is not valid,
BACnet/IP communications cannot be established and the device does not initiate or respond to
BACnet messages. If the IP address is changed at run-time and the IP address is not valid, BACnet/IP

12 ED 15117
communications are disabled. However, once a valid IP address is received, BACnet/IP
communications are then enabled. Changing the IP address may affect the operation of other BACnet
devices on the network. This parameter can only be accessed and configured via the unit controller
OITS panel.
Subnet Mask
The Subnet Mask is read from a parameter in the Magnitude Chiller Unit Controller during the BACnet
communication module’s initialization phase. The BACnet communication module continues to poll
the Subnet Mask parameter during run-time. If the Subnet Mask is changed at the unit controller during
run-time, the update is automatically applied to the BACnet communication module as soon as the
change is received. The validity of the Subnet Mask is verified against the IP address. If the Subnet
Mask is not valid, the BACnet communication module does not enable BACnet/IP communications
and the device does not initiate or respond to BACnet messages. If the Subnet Mask is changed at run-
time and is not valid, the BACnet/IP communications are disabled. However, once a valid Subnet
Mask is received, BACnet/IP communications are then enabled. Changing the Subnet Mask may affect
the operation of other BACnet devices on the network. This parameter can only be accessed and
configured via the unit controller OITS panel.
UDP Port
The UDP Port is read from the Magnitude Chiller Unit Controller during the BACnet communication
module’s initialization phase. The BACnet communication module continues to poll the UDP Port
parameter during run-time. If the UDP Port is changed at the unit controller during run-time, the update
is automatically applied to the BACnet communication module as soon as the change is received.
Changing the UDP Port may affect the operation of other BACnet devices on the network. This
parameter can only be accessed and configured via the unit controller OITS panel.
Default Gateway Address
The default gateway address is read from a parameter in the Magnitude Chiller Unit Controller during
the BACnet communication module’s initialization phase. The BACnet communication module
continues to poll the default gateway address parameter during run-time. If the default gateway address
is changed at the unit controller during run-time, the update is automatically applied to the BACnet
communication module as soon as the change is received. Modifying the default gateway address may
affect the operation of other BACnet devices on the network. This parameter can only be accessed and
configured via the unit controller OITS panel.
BBMD Address
The BBMD address is read from the Magnitude Chiller Unit Controller during the BACnet
communication module’s initialization phase. If the BBMD address is not 0.0.0.0, the BACnet
communication module sends a Register-Foreign-Device message to the address. If the result code
returned is X’0000’, the BACnet communication module renews the registration at the period defined
by the Foreign Device Time-To-Live value. The BACnet communication module continues to poll the
BBMD address parameter during run-time. If the BBMD address is changed at the unit controller
during run-time, the update is automatically applied to the BACnet communication module as soon as
the change is received. If the new value is 0.0.0.0, a Delete-Foreign-Device-Table-Entry message is
sent to the BBMD address. If the new value is non-zero, a Register-Foreign-Device message is sent to
the BBMD address. Changing the BBMD address may affect the operation of other BACnet devices
on the network. This parameter can only be accessed and configured via the unit controller OITS
panel.

ED15117 13
Foreign Device Time-To-Live
The Foreign Device Time-To-Live (FDTTL) value is read from the Magnitude Chiller Unit Controller
during the BACnet communication module’s initialization phase. The BACnet communication module
continues to poll the FDTTL parameter during run-time. If the FDTTL is changed at the unit controller
during run-time, the update is automatically applied to the BACnet communication module as soon as
the change is received. If the new value is different from the existing value, a Register-Foreign-Device
message is sent to the BBMD address. This parameter can only be accessed and configured via the unit
controller OITS panel.
BACnet MS/TP Communication Parameters
The BACnet MS/TP communication setup parameters consist of: the Device Object Name, Device
Object Identifier, Max Master, Max_Info_Frames, MAC Address and Baud Rate. These parameters can
only be accessed and configured via the unit controller OITS panel. Both the MAC Address and the
Baud Rate settings require configuration prior to establishing communication from the unit controller
to the BACnet network.
MAC Address
The MAC address is read from a parameter in the Magnitude Chiller Unit Controller during the
BACnet communication module’s initialization phase. This parameter can only be accessed and
configured via the unit controller OITS panel. It is not accessible from the BACnet network interface
(i.e. Building Automation System workstation). The BACnet communication module continues to poll
the MAC address parameter during run-time. If the MAC address is changed at the unit controller
during run-time, the update is automatically applied to the BACnet communication module as soon as
the change is received. Changing the MAC address may affect the operation of other BACnet devices
on the network.
The allowable range of values for the MAC address is: 0-127. Since the BACnet communication
module is always configured as an MS/TP master, only addresses 0-127 are valid. If a value greater
than 127 is read from the unit controller, the BACnet communication module defaults to a MAC
address of 127. The MAC address must be unique on the BACnet MS/TP network.
Baud Rate
The baud rate is read from a parameter in the Magnitude Chiller Unit Controller during the BACnet
communication module’s initialization phase. The Baud Rate must match the other devices on the same
MS/TP network and requires configuration prior to establishing communications from the unit
controller to the BACnet network. This parameter can only be accessed and configured via the unit
controller OITS panel. It is not accessible from the BACnet network interface (i.e. Building
Automation System workstation).
The BACnet communication module continues to poll the baud rate parameter during run-time. If the
baud rate is changed at the unit controller during run-time, the update is automatically applied to the
BACnet communication module as soon as the change is received. Baud rates supported are as
follows: 9600, 19200, 38400 (default) and 76800 bps.
BACnet Device Management
The following functions are specific to the BACnet device. These functions are used for maintenance
and testing. A network management tool such as VTS is typically used to issue the network commands.
DeviceCommunicationControl - Disable
The purpose of this command is to reduce network traffic for diagnostic testing of the BACnet network.
When the BACnet communication module receives a network command to Disable communications it
stops communicating information to the network. An optional time may be specified for how long to

14 ED 15117
suspend communications. The unit continues to operate during the Disabled state. A password of 1234
is required.
DeviceCommunicationControl - Enable
When the BACnet Communication module receives a network command to Enable, the chiller unit
controller communication to BACnet is restored. A password of 1234 is required.
ReinitializeDevice (Reset)
When the BACnet Communication module is capable of receiving a network ReinitializeDevice
command to reboot itself (cold start or warm start). The functionality of a cold and warm start are the
same and simply reboot the BACnet
Communication module. The chiller controller can never be reset via the BACnet network.
Reinitialize Device is implemented with a non-changeable password of 1234.

ED15117 15
Configuring the Unit Controller
The Magnitude Chiller Unit Controller can operate with the default values of the various parameters.
However, certain communication parameters must be configured appropriately (see the appropriate
Magnitude Communication Module Installation Manual for details). Default values may be changed
using the unit controller OITS panel or via the BACnet network (see the Magnitude Chiller Unit
Controller Operation & Maintenance Manual, OM 1034 for details).
LONWORKS Networks
LONWORKS technology, developed by Echelon Corporation, is the basis for LONMARK Interoperable
Systems. This technology is independent of the communication media. The LONMARK Interoperable
Association has developed standards for interoperable LONWORKS technology systems. In particular
they have published standards for HVAC equipment including the Chiller Functional profile. This
profile specifies a number of mandatory and optional standard network variables and standard
configuration parameters. This manual defines the variables and parameters available in the Magnitude
Chiller Unit Controller.
Compatibility
The Magnitude Chiller Unit Controller, along with the LONWORKS Communication Module, operates
in accordance with the Chiller Functional profile of the LONMARK Interoperability Association.
LONWORKS Variables
The Magnitude Chiller Unit Controller incorporates LONWORKS network variables to access unit data
points. The controller uses LONWORKS Standard Network Variable Types (SNVT) from the profile.
Some data points can be adjusted (input network variables, nvi) (read/write attributes, e.g., setpoints)
from the network and others can only be interrogated (network variables, nvo) (read only attributes,
e.g., status information). Configuration variables (nci) are included with the input network variables.
Each data point accessible from a LONWORKS network is described with a table that gives the
LONWORKS Name, Profile, SNVT Type, and SNVT Index. If the variable is a configuration variable
the table also includes the SCPT (Standard Configuration Parameter Type) Reference and the SCPT
Index.
Example of LONWORKS Data Point
LONWORKS Name Profile SNVT Type SNVT Index SNVT Size
nvoSuctionTemp McQuayChiller SNVT_temp_p 105 two bytes
LONWORKS Name
Each network variable has a name that you use to access the data point. This is the name of the variable
from the profile. In the example above, the name of the variable is nvoSuctionTemp.
Profile
The profile column designates whether the variable is defined in the LONMARK Chiller functional
profile or is a McQuay proprietary variable. The variable itself may not be a standard component of the
profile, but the unit controller implements it and it is available to the network. The Profile column
indicates “Chiller” for LONMARK standard network variables or “McQuayChiller” for proprietary
variables.
SNVT Type
This column gives the name of the standard network variable type from the master list. In the example
above, the SNVT is SNVT_temp_p.

16 ED 15117
SNVT Index
This column gives the Index of the standard network variable type from the master list. In the example
above, the SNVT Index is 105.
SNVT Size
This column gives the size of the standard network variable type in number of bytes. In the example
above, the SNVT Size is two bytes.
SCPT Reference
This column gives the name of the Standard Configuration Parameter Type (SCPT) from the master
list.
SCPT Index
This column gives the Index of the Standard Configuration Parameter Type (SCPT) from the master
list.
Network Considerations
Network Topology
Each LONWORKS Communication Module is equipped with an FTT-10A transceiver for network
communication. This transceiver allows for (1) free topology network wiring schemes using twisted
pair (unshielded) cable and (2) polarity insensitive connections at each node. These features greatly
simplify installation and reduce network commissioning problems. Additional nodes may be added
with little regard to existing cable routing.
Free Topology Networks
A LONWORKS “free topology network” means that devices (nodes) can be connected to the network in
a variety of geometric configurations. For example, devices can be daisy-chained from one device to
the next, connected with stub cables branching off from a main cable, connected using a tree or star
topology, or any of these configurations can be mixed on the same network as shown in Figure 1. Free
topology segments require termination for proper transmission performance. Only one termination is
required. It may be placed anywhere along the segment. Refer to Echelon LONWORKS FTT-10A
Transceiver User’s Guide.
Free topology networks may take on the following topologies:
Bus
Ring
Star
Mixed - Any combination of Bus, Ring, and Star
Limitations to wire lengths apply and must be observed.

Figure 1. Singly Terminated Free Topology
Te r m i n at i o n
Star Topology
Termination
Ri
ng
T
opo
l
ogy
Termination
Singly Terminated Bus Topology
Stub
}
Termination
Mixed Topology
A network segment is any part of the free topology network in which each conductor is electrically
continuous. Each of the four diagrams in is a illustration of a network segment. Some applications may
require two or more segments. See Free Topology Restrictions. If necessary, segments can be joined
with FTT-10A-to-FTT-10A physical layer repeaters. See Figure 2.
Figure 2. Combining Network Segments with a Repeater
Termination Te rm i n a ti o n
FTT-10A FTT-10A
Free Topology Restrictions
Although free topology wiring is very flexible, there are restrictions. A summary follows:
The maximum number of nodes per segment is 64.
The maximum total bus length depends on the wire size:
Wire
Size Maximum Node-to-Node Length Maximum Cable Length
24 AWG 820 ft (250 m) 1476 ft (450 m)
22 AWG 1312 ft (400 m) 1640 ft (500 m)
16 AWG 1640 ft (500 m) 1640 ft (500 m)
The longest cable path between any possible pair of nodes on a segment must not exceed the maximum
node-to-node distance. If two or more paths exist between a pair of nodes (e.g., a loop topology), the
longest path should be considered. Note that in a bus topology, the longest node-to-node distance is
equal to the total cable length. The total length of all cable in a segment must not exceed the maximum
total cable length. One termination is required in each segment. It may be located anywhere along the
segment.
Doubly Terminated Networks
You can extend the maximum total cable length without using a repeater by using doubly-terminated
network topology. The trade-offs are (1) this network topology must be rigorously followed during the
installation and subsequent retrofits and (2) two terminations must be installed at the ends of the bus for
proper transmission performance.
Limitations to wire lengths apply and must be observed.
ED15117 17

Figure 3. Doubly Terminated Network Topology
Termination Termination
Doubly Terminated Topology Restrictions
The restrictions on doubly-terminated bus topology are as follows:
The maximum number of nodes per segment is 64. The maximum total bus length depends on the wire
size:
Wire Size Maximum Cable
Length
24 AWG 2952 ft (900 m)
22 AWG 4590 ft (1400 m)
16 AWG 8855 ft (2700 m)
The maximum stub length is 9.8 ft (3 m). A stub is a piece of cable that is wired between the node and
the bus (see Figure 1.) Note that if the bus is wired directly to the node, there is no stub, and thus
the stub length is zero. If you are wiring to a field terminal strip on a unit, be sure to account for any
factory wiring between the terminal strip and the controller. This wiring is considered part of the
stub. Two terminations are required in each segment. One must be located at each end of the bus.
Network Cable Termination
LONWORKS network segments require termination for proper data transmission performance. The type
and number of terminations depend on network topology.
LONWORKS Network Addressing
Every Neuron® Chip has a unique 48-bit Neuron ID or physical address. This address is generally used
only at initial installation or for diagnostic purposes. For normal network operation, a device address is
used. Device addresses are defined at the time of network configuration. All device addresses have
three parts. The first part is the Domain ID, designating the domain. Devices must be in the same
domain in order to communicate with each other. The second part is the Subnet ID that specifies a
collection of up to 127 devices that are on a single channel or a set of channels connected by repeaters.
There may be up to 255 subnets in a domain. The third part is the Node ID that identifies an individual
device within the subnet.
A group is a logical collection of devices within a domain. Groups are assembled with regard for their
physical location in the domain. There may be up to 256 groups in a domain. A group address is the
address that identifies all devices of the group. There may be any number of devices in a group when
unacknowledged messaging is used. Groups are limited to 64 devices if acknowledged messaging is
used. A broadcast address identifies all devices within a subnet or domain.
Commissioning the Network
Pressing the service pin, switch on the LONWORKS Communication Module, generates a service pin
message, which contains the Neuron ID and the program code identification of the node. A service pin
message is a network message that is generated by a node and broadcast on the network. It can be used
to commission the LONWORKS network. A network configuration tool maps device Neuron IDs to the
domain/subnet/node logical addressing scheme when it creates the network image, the logical network
addresses and connection information for all devices (nodes) on the network.
18 ED 15117

ED15117 19
External Interface File (XIF)
LONMARK guidelines specify exact documentation rules so that proprietary configuration tools are not
required to commission and configure LONWORKS devices. The LONWORKS Chiller Communication
Module is self-documenting so that any network management tool can obtain all the information
needed over the network to connect it into the system and to configure and manage it. An external
interface file (a specially formatted PC text file with an extension .XIF) is available so that any network
tool can design and configure it prior to installation. XIFs are available on www.mcquay.com or
www.lonmark.org.
Resource Files
The Magnitude Chiller Unit Controller supports variables defined by the LONMARK Chiller functional
profile as well as McQuay proprietary variables. The variable itself may not be a standard component
of the profile, but the unit controller implements it and it is available to the network. Resource Files
provide definitions of functional profiles, type definitions, enumerations, and formats that can be used
by network configuration tools such as Echelon’s LonMaker®program. Refer to the Detailed Data
Section for each variable to determine if it is supported by the standard LONMARK Chiller functional
profile or is a proprietary variable. Within the Detailed Data Section, each parameter includes a
LONWORKS table with a Profile column. The Profile column indicates “Chiller” for a LONMARK
standard network variable or “McQuayChiller” for a proprietary variable. The Resource Files define
the format of how these McQuay-specific variables are displayed when using a tool such as LonMaker.
The Resource Files are available on www.mcquay.com or www.lonmark.org.
Unit Controller Default Values
The Magnitude Chiller Unit Controller and the LONWORKS Communication Module are designed in
accordance with the LONMARK chiller functional profile. The unit can operate with the default values
of the various parameters. However, the Protocol Type must be set to LONWORKS. Additional
configuration may be necessary for optimal unit performance and network integration. Default values
may be changed via the unit controller OITS panel and/or the BACnet network. Refer to the
appropriate operation manual for default values and unit controller operating instructions (see
Reference Documents section for details.)
Data Integrity
The integrity of some data depends on a valid network connection to maintain current values. The
following data points require a valid network connection. If a data point listed in Table 2 does not
change after a given time (receive heartbeat), the controller reverts to the value contained in the
corresponding network configuration variable (nci). The receive heartbeat feature is only applicable
when nciDefaults is set to 0.
Table 2. Receive Heart Beat Variables
Data Point LONWORKS Variable
Capacity Limit Setpoint nviCapacityLim
Chiller Enable Setpoint nviChillerEnable
Cool Setpoint nviCoolSetpt
Heat Setpoint nviHeatSetpt
Ice Setpoint nviIceSpt
Chiller Mode Setpoint nviMode

20 ED 15117
Typical Application: Minimum Integration
This section gives you the basic information required for integrating the Magnitude Chiller Unit
Controller to a BAS and outlines a procedure to set up the unit for network control.
Set up the Unit Controller for Network Control
From the unit controller OITS panel, follow the steps below:
1. Set the Control Source on the SET/UNIT screen to USER.
2. Change the BAS Network Protocol default to the appropriate BAS Protocol on the SET/BAS
screen.
3. Verify with the chiller/control company technician that the chiller is operational on the BAS.
4. Set the Control Source on the SET/UNIT screen to BAS.
Display Important Data Points
Typical workstation displays of Magnitude Chiller Unit Controller attributes include the following
significant data points (page number of detailed description in parenthesis). Each data point is
identified with a number that also identifies it in the respective BACnet or LONWORKS Protocol Point
Summary tables. These data points are also shaded in the comprehensive tables so that you can
distinguish them from the rest of the data points in the table. References in the text of this section also
identify these data points with a number and shading.
Table 3. Significant Data Points
No
.
Configuratio
n
No
.Temperatures No .Setpoints No .Alarms
1 Chiller Status (37) 5
Evaporator Entering
Water Temperature (50) 9 Cool Setpoint – Network
(49) 11 Alarm Digital Output (29)
2 Chiller Mode Set-point
(36) 6 Evaporator Leaving
Water Temperature (51) 10 Capacity Limit Setpoint – Network (30) 12 Clear Alarm Network (38)
3 Actual Capacity (28) 7 Condenser Entering
Water Temperature (45)
4 Chiller Enable Setpoint
(32) 8 Condenser Leaving
Water Temperature (46)
You can display any number of additional data points based on job requirements or individual
preference. See Protocol Point Summary section (Tables 4-7) for a complete list of all LONWORKS
variables or BACnet points available to the network. For a detailed description of all available data
points, see the Detailed Data Point Information section.