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SYSTIMAX® Solutions

Johnson Controls Metasys® System Over CommScope SYSTIMAX CablingDesign and Implementation DocumentDecember 2009

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Chapter 1 Executive Summary 4

Chapter 2 JCI Metasys Solution Architecture 5

2.1 Overview 5

2.2 Communication Media 7

2.2.1 Metasys BACnet Family 7

2.2.2 Metasys LON Family 8

2.2.3 Metasys N2 Bus Family 8

Chapter 3 Physical Layer Design 9

3.1 IP over Ethernet Network 9

3.2 BACnet over MS/TP Network 12

3.2.1 FC Bus 13

3.2.2 SA Bus 14

3.2.3 End-of-Line Termination on the MS/TP Bus 16

3.2.4 MS/TP Bus Cable Recommendation from JCI 16

3.2.5 SYSTIMAX Guidelines for FC bus 16

3.2.5.1 FC Chained Branches 17

3.2.5.2 FC Chained Devices 18

3.2.6 SYSTIMAX Guidelines for SA bus 19

3.2.6.1 SA Chained Branches 20

3.2.6.2 SA Chained Devices 21

3.3 LON (LonWorks) Network 22

3.4 N2 Bus Network 23

3.4.1 End-of-Line (EOL) 24

3.4.2 SYSTIMAX Guidelines for N2 bus 24

3.4.2.1 N2 Chained Branches 25

3.4.2.2 N2 Chained Devices 25

3.4.2.3 Calculating the Number of Chained Branches per N2 Segment 26

3.5 Lightning Protection Circuitry 27

3.6 Input/Output Device Guidelines 27

3.6.1 Analog Inputs 27

3.6.1.1 Temperature Sensors 27

3.6.1.2 Powered Sensors 29

3.6.2 Analog Outputs 29

3.6.3 Digital Outputs 30

4.0 References 30

Contents

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This design and implementation document represents a collaborative development effort between CommScope and Johnson Controls Inc. (JCI). It is in addition to design and installation guidelines from CommScope SYSTIMAX documents and JCI documents.

CommScope/JCI Validated DesignThe CommScope/JCI Validated Design consists of systems and solutions designed, tested, and documented to facilitate faster, more reliable, and more predictable customer deployments.

THE DESIGNS ARE SUBJECT TO CHANGE WITHOUT NOTICE. USERS ARE SOLELY RESPONSIBLE FOR THEIR APPLICATION OF THE DESIGNS. THE DESIGNS DO NOT CONSTITUTE THE TECHNICAL OR OTHER PROFESSIONAL ADVICE OF COMMSCOPE AND JCI, THEIR SUPPLIERS OR PARTNERS. USERS SHOULD CONSULT THEIR OWN TECHNICAL ADVISORS BEFORE IMPLEMENTING THE DESIGNS. RESULTS MAY VARY DEPENDING ON FACTORS NOT TESTED BY COMMSCOPE AND JCI.

CommScope 1100 CommScope Place SE Hickory, North Carolina 28603

www.commscope.com

Johnson Controls IncBuilding Efficiency507 E. Michigan StreetMilwaukee, WI 53202

www.johnsoncontrols.com

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Chapter 1 Executive SummaryThis Design and Implementation Document (DID) represents a collaborative effort between CommScope and Johnson Controls Inc. (JCI) in support of the CommScope-JCI relationship. The intent of this document is to provide guidance to the respective sales and technical organizations of each party in the relationship for the design and implementation of a Johnson Controls Building Automation System (BAS) network running over CommScope Intelligent Building Infrastructure Solutions (IBIS).

This DID is an extension of the SYSTIMAX Johnson Controls Metasys® Design Guide that was published in 1995 that offered building owners greater flexibility by providing a single structured cabling infrastructure to handle all information traffic -- from voice, data, or video to building management functions such as security systems or heating, ventilation and air conditioning (HVAC).

CommScope IBIS is a modular, flexible cabling infrastructure system that supports voice, data, video and BAS by providing a robust and cost effective connectivity for all of a building’s BAS and communication systems. IBIS utilizes twisted pair and/or fiber optic cabling to provide connectivity in an open architecture environment. In addition, combining CommScope IBIS with CommScope iPatch Intelligent Infrastructure Solution provides the user with control of the physical infrastructure.

CommScope IBIS can support traditional BAS systems based on direct-digital control communication protocols over RS-485 low voltage control networks and newer protocols such as BACnet over MS/TP, LONWorks over FTT-10 or IP over Ethernet networks using various CommScope SYSTIMAX solutions.

There are several standards that describe how BAS can be designed and implemented over structured cabling systems. The standards that supplement this DID are:

1. ANSI/TIA-862 ‘Building Automation Cabling Standard’. This standard specifies a generic cabling system for BAS used in commercial buildings that will support a multi-vendor environment. The purpose of this standard is to enable the planning and installation of a structured cabling system for BAS applications used in new or renovated commercial premises. It establishes performance, topology and technical criteria for various cabling system configurations for connecting BAS equipment and devices. It also provides information that may be used for the design of commercial BAS products.

2. ISO/IEC IS 15018 ‘Generic Cabling for Homes’. This standard specifies a generic cabling system for applications used in homes and multi-dwelling units. It includes support for CCCB (commands, controls and communications in buildings) applications which encompass lighting controls, building controls, security and fire alarms.

3. CENELEC EN 50173-4 ‘Generic Cabling Systems – Part 4: Homes’. This standard specifies a generic cabling system for applications used in homes and multi-dwelling units. It is very similar to ISO/IEC IS 15018.

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Chapter 2 JCI Metasys Solution Architecture 2.1 OverviewEvery building has to meet several basic requirements such as security, fire-life-safety, ventilation, lighting, health and comfort. Security comes from the need to protect property, content and personnel. Examples of security requirements are identification of vehicles entering and exiting a car park, controlling access to sensitive or secured areas, and precautions against terrorist bomb threats, robberies and burglaries.

Fire safety remains a top priority for high rise office buildings and large shopping malls. The ability to locate and contain the source of a fire rapidly, reduce time to locate missing personnel and facilitate access control is very important. In order to effectively perform these functions, buildings will require fire monitoring and sprinkler systems, lift and access control systems, a public address system and a personnel database.

There is also a need for energy conservation due to dwindling natural resources, and concerns about global warming. This is compounded by a host of regulations especially in Europe. Buildings produce half the carbon dioxide emission and are now more rigorously regulated with new directives. These have resulted in an increasing demand for more efficient and ‘greener’ buildings. All these require efficient HVAC and lighting control together with an electrical demand monitoring system.

The JCI Metasys system offers data communications and information management via a two level communications architecture (see Figure 1), PC-based workstations, and microprocessor-based controllers and equipment. This results in three levels of BAS equipment plus the endpoint devices:

Level 0 equipment consists of the endpoint devices (i.e. sensors and actuators)•

Level 1 equipment is the system and local control units (e.g. NCEs, FECs, LN-series)•

Level 2 equipment is the master network or building controllers (e.g. NAEs)•

Level 3 equipment is the server (e.g. Application and Data Server [ADS] or Extended •Application and Data Server [ADX])

The top level of the communications architecture is a LAN of Metasys controllers and servers and the network software that enable them to communicate. This is based on IEEE 802.3 10/100/1000BASE-T LAN standards. The server (ADS or ADX) is a component of the Metasys system that manages the collection and presentation of large amounts of trend data, event messages, operator transactions, and system configuration data. As Site Director, the server provides secure communication to a network of Network Automation Engines (NAEs), Network Control Engines (NCEs), and Network Integration Engines (NIEs).

The second level of the communications architecture supports BACnet (Building Automation Control Network) protocol, LonTalk protocol, and JCI legacy N2 bus protocol. BACnet was developed by ASHRAE and is now an ISO standard (ISO 16484-5). It is designed to maximize interoperability across many products, systems and vendors in commercial buildings. BACnet devices are connected directly to the IP Ethernet network or to the MS/TP Field Bus.

LonTalk is a standard open protocol developed by Echelon and is now an ISO standard (ISO/IEC/EN 14908 series). It provides sensor and controller connectivity. LonWorks enabled controllers from Johnson Controls or LonMark certified devices from other manufacturers can be integrated into the Metasys system architecture via the LonWorks network.

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In a similar fashion, Metasys connects to N2 protocol devices via the N2 bus. The N2 bus is a modified RS-485 network that links Network Control Modules (NCMs), which reside in NCUs, to N2 bus devices such as the Application Specific Controllers (ASCs), Digital Controller Modules (DCMs), Point Multiplex Modules (XBN, XRE, XRL, XRM) and Digital Expansion Modules (XMs). The N2 bus uses a master/slave protocol, in which the master device, the NCM, initiates all communication with the N2 bus devices.

The NAE is a Web-enabled, Ethernet-based supervisory controller that monitors and supervises networks of field-level building automation devices that typically control HVAC equipment; lighting; security; fire; and building access. The NAE provides features including alarm and event management, trending, archiving, energy management, scheduling, and password protection through its embedded Site Management Portal.

Figure 1: JCI Metasys Solution Architecture

ETHERNET

Figure 1

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Different models and options support various communications protocols including BACnet/IP, BACnet Master-Slave/Token-Passing (MS/TP), N2 Bus, N2 over Ethernet, and LonWorks network devices.

The NCE combines the network supervisor capabilities and IP network connectivity of an NAE with the I/O point connectivity and direct digital control capabilities of a Metasys Field Equipment Controller (FEC). The NCE provides a cost-effective solution designed for central plants and large built-up air handler applications. All NCE models provide IP Ethernet network connectivity, the Site Management Portal, and the network supervisory functions featured on network automation engines, including the BACnet IP integration. Depending on the model, an NCE supports either a BACnet MS/TP trunk, an N2 bus trunk, or a LonWorks network trunk.

The NIE is a Web-enabled supervisory controller for integration of Metasys N1 networks. The NIE is a specialized version of the NAE and is designed to provide for the migration of existing N1 networks into the Metasys system extended architecture. The NIE provides the same Site Management Portal as the NAE. Unlike the NAE, the NIE does not support integration of BACnet MS/TP or BACnet IP, N2, and LonWorks networks. The N1 bus network is not covered in this document.

The NCM and NAE perform very similar control and functions of the subservient controllers. The NCM however does not have the hardware capabilities of running an embedded Windows OS or a web server.

2.2 Communication Media

2.2.1 Metasys BACnet FamilyBACnet supports five media types including Ethernet, RS-485, Arcnet, LON and RS-232 (see Figure 2. Addendum Q has been approved that adds IEEE 802.15.4 ZigBee as an approved data link). The RS-485 interface uses the MS/TP (Master-Slave/Token-Passing) protocol to communicate between the physical and network layers.

Figure 2: BACnet collapsed architecture

BACnet Application Layer

BACnet Network Layer

ISO 8802-2 (IEEE 802.3) Type 1

ISO 8802-3 (IEEE 802.3)

ARCNET

MS/TP PTP

EIA-485 EIA-232

LonTalk

IEEE 802.15

ZigBee

Application

Network

Data Link

Physical

BACnet Layers Equivalent OSI Layers

Figure 2

The Metasys BACnet family provides a fully-programmable, high-performance line of devices including FECs, Input/Output Modules (IOMs), Network Sensors, and Variable Air Volume (VAV) Modular Assembly (VMA) 1600 controllers. FECs are stand-alone digital control devices that apply to a wide range of HVAC and other building system applications. The Metasys BACnet family of controllers uses BACnet/IP (Ethernet interface) or BACnet MS/TP (RS-485 interface) for communication. MS/TP is a token-passing network field bus. The protocol supports a combination of shared resource and peer-to-peer communications, where more than one controller can be the network master at any given time. Electrically, MS/TP adheres to the RS-485 standard. The MS/TP bus connects NAE/NCEs and field controllers using BACnet MS/TP protocol. Two tiers of MS/TP buses exist in the Metasys architecture. The Field Controller Bus (FC Bus) consists of BACnet controllers and point interfaces supervised by an NAE/NCE. The Sensor Actuator (SA) Bus consists of point interfaces and networked sensors supervised by a field controller.

2.2.2 Metasys LON FamilyThe Metasys system LN Series controllers use the LonWorks communication protocol. LN Series controllers are available either in fully-programmable or LonMark profile-compliant configurable models. LN Series application-specific controllers allow you to control equipment, such as rooftop units, fan coils, heat pumps, unit ventilators, VAV boxes, and other terminal units. LN Series programmable controllers apply to multistage air handling units, chillers, boilers, and refrigeration systems. The LonWorks network links LonWorks enabled devices to the NAE/NCE. The NAE acts as a supervisory controller and communication path to the Metasys system for a network of LonWorks enabled devices. The NAE supports any LonWorks enabled device if the network interface follows the current LonMark Guidelines and uses the Free Topology Transceiver FTT10, including all current LonMark certified devices from Johnson Controls such as:

LN Series Controllers including programmable controllers, application specific controllers, •and displays and schedulers

Terminal Control Units (TCUs)•

Programmable NexSys Flexible System Controllers (FSCs)•

2.2.3 Metasys N2 Bus FamilyThe N2 communications bus is a local network that links controllers and point interfaces to the NCM. The N2 bus uses a master/slave protocol, in which the master device, the NCM, initiates all communication with the N2 Bus devices. These N2 bus devices include the DCMs, Point Multiplex Modules (XBN, XRE, XRL, XRM), and all ASCs. The N2 bus is based on a modified RS-485 interface.

The N2 bus is wired in a daisy-chained fashion. The N2 bus can use either solid or stranded wire. It can also use optical fiber when special fiber modems are used. Choices include:

3-wire twisted cable•

Two twisted pair telephone cable•

Two twisted pair cable with a shield•

Duplex optical fiber (requires a pair of fiber modems•

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Chapter 3 Physical Layer Design

CommScope IBIS supports cabling for the installation of Johnson Controls Metasys systems using various CommScope SYSTIMAX solutions. The purpose of this chapter is to help customers identify and implement CommScope IBIS connectivity solutions for the Metasys systems. Only IP over Ethernet network, BACnet over MS/TP network, LonWorks over FTT-10 network and the N2 bus are considered.

3.1 IP over Ethernet NetworkEthernet/IP network devices are capable of transmitting at 10 Mb/s, 100 Mb/s, 1000 Mb/s and 10000 Mb/s rates. This section focuses on Ethernet/IP connectivity guidelines using CommScope twisted pair and fiber solutions.

CommScope recommends the T568B layout for installations. See Figure 3.

Figure 3: ANSI/TIA T568B pin assignment

Table 1 provides the distances supported by CommScope twisted pair solutions for various Ethernet/IP LANs and Table 2 provides CommScope PowerSUM, GigaSPEED XL (GSXL) and GigaSPEED X10D (GSX10D) solution components.

Table 3 provides the distances supported by CommScope fiber solutions for various Ethernet/IP LANs.

TABLE 1: MAXIMUM SUPPORTED DISTANCES USING COMMSCOPE POWERSUM, GSXL AND GSX10D SOLUTIONS

Ethernet/IP LANs Maximum Distance in meters

PowerSUM GigaSPEED XL GigaSPEED X10D

100BASE-TX 100 1, 962, 923 1171, 115 2, 1103 1171, 1152, 1103

1000BASE-T 100 1, 962, 923 1171, 115 2, 1103 1171, 1152, 1103

10GBASE-T Not Supported Limited Support4 1001, 962, 923

Notes: 1 For 20 °C 2 For 30 °C 3 For 40 °C 4 Mitigation procedures according to ISO/IEC TR 24750 and TIA TSB-155 may be required to ensure support.

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TABLE 2: COMMSCOPE POWERSUM, GIGASPEED XL AND GIGASPEED X10D SOLUTION COMPONENTS

PowerSUM GigaSPEED XL GigaSPEED X10D GSX10D

Patch Panel

1100PSCAT5EPM2150PSE

1100GS3 (U/UTP)PM-GS3 (U/UTP)VisiPatch (U/UTP)iPatch 1100GS3 (U/UTP)iPatch M4200i (U/UTP & F/UTP)

1100GS5 (U/UTP)PM-GS5 (U/UTP)M2000/M3000 (U/UTP)VisiPatch 360 (U/UTP)M3200 (F/UTP)iPatch 1100GS5 (U/UTP)iPatch M4200i (U/UTP & F/UTP)

Cable 1061 Nonplenum (U/UTP)2061 Plenum (U/UTP)3061 LSZH (U/UTP)

1071 Nonplenum (U/UTP)2071 Plenum (U/UTP)3071 LSZH (U/UTP)

1091 Nonplenum (U/UTP)2091 Plenum (U/UTP)3091 LSZH (U/UTP)1291 Nonplenum (F/UTP)2291 Plenum (F/UTP)3291 LSZH (F/UTP)

Outlet MPS100E (U/UTP) MGS400 (U/UTP) MGS600 (U/UTP)MFP520 (F/UTP)

Cords DP8S (U/UTP) GS8E Nonplenum (U/UTP)GS8E-SND Nonplenum (U/UTP)GS8E-SPD Plenum (U/UTP)GS8H LSZH (U/UTP)GS8E-SLD LSZH (U/UTP)

GS10E Nonplenum (U/UTP)GS10E-P Plenum (U/UTPGS10E-L LSZH (U/UTP)G10FP Nonplenum (F/UTP)G10FP-L LSZH (F/UTP)

Ethernet/ IP LANs

Maximum Distance in meters a, b, c

OptiSPEED MM LazrSPEED 150 LazrSPEED 300 LazrSPEED 550 TeraSPEED

1000BASE-SX @ 850 nm

300 800 1000 1100 N/A

1000BASE-LX @ 1300 nm

600 600 600 600 N/A

1000BASE-LX @ 1310 nm

N/A N/A N/A N/A 5000

10GBASE-S @ 850 nm

33 150 300 550 N/A

10GBASE-LX4 @ 1300 nm

300 300 300 300 10000

10GBASE-L @ 1310 nm

N/A N/A N/A N/A 10000

10GBASE-E @ 1550 nm

N/A N/A N/A N/A 40000

TABLE 3: MAXIMUM SUPPORTED DISTANCES USING COMMSCOPE OPTISPEED, LAZRSPEED AND TERASPEED SOLUTIONS

Notes: a Assumes the use of two LC connectors and zero splices. b Excludes connectors at the device end-points. c Please refer to ‘SYSTIMAX Performance Specification, Volume 1 – SYSTIMAX Applications’

for more detail information.


Horizontal cable

Coverage Area Equipment Room

Outlet

Cord

Patch Panel

Ethernet Switch

Administrator PC

Figure 4

Horizontal cable

Coverage Area Floor Distributor

Outlet

Patch Panel

Ethernet Switch

Horizontal cable


Outlet

Cord

Patch Panel

Ethernet Switch

Administrator PC

Second Floor

First Floor

Cop

per

Bac

kbon

e D

istr

ibut

ion

Figure 5

Figure 4 shows an intra-room connectivity for an Ethernet network. Figures 5 and 6 show inter-floor connectivities with copper and fiber optic backbone respectively.

Figure 4: Intra-room Ethernet connectivity

Figure 5: Inter-floor Ethernet connectivity with copper backbone


Figure 6: Inter-floor Ethernet connectivity with fiber optic backbone

Horizontal cable

Coverage Area Floor Distributor

Outlet

Patch Panel

Ethernet Switch

Horizontal cable


Outlet

Cord

Patch Panel

Ethernet Switch

Administrator PC

Second Floor

First Floor

Fib

er B

ackb

one

Dis

trib

utio

n

Fiber Optic Panel

Fiber Optic Panel

Figure 63.2 BACnet over MS/TP NetworkThe BACnet MS/TP communications bus is a local network that connects supervisory controllers and field controllers to field point interfaces. The data interface is RS-485.

IMPORTANT: Do not connect MS/TP devices and N2 devices to the same bus. MS/TP Communications Buses follow different protocol and wiring rules from N2 Communications Buses, and MS/TP devices and N2 devices are not compatible on the same bus.

An MS/TP bus (Figure 7) supports two types/levels of buses: a FC Bus and a SA Bus. The FC bus and the SA bus are networks of daisy-chained devices.

An MS/TP bus can be configured to communicate at one of four different baud rates. It is very important that all of the devices on an MS/TP bus communicate at the same baud rate. The baud rate setting determines the rate at which devices communicate data over the bus. The baud rate settings available on Metasys MS/TP devices are 9600, 19200, 38400, 76800 and Auto. The baud rate setting for Metasys devices is set in the Metasys software. JCI recommends setting all MS/TP bus supervisors (NAEs and NCEs) to 38400, and all field controllers on the FC bus (FECs, VMA1600s and IOMs) to Auto.

Note: Some third-party devices do not support all four baud rates. The NAE55xx-0 models do not support 76800 baud.

Please refer to ‘JCI MS/TP Communications Bus Technical Bulletin’ for more detailed information on the MS/TP communications bus.


3.2.1 FC BusAn FC bus connects a Metasys system NAE or NCE to FECs, VMA1600s, Input/Output Modules (IOMs), TEC26xx series thermostats, and Variable Speed Drives (VSDs). On an FC bus, the NAE or NCE is the bus supervisor. An FC bus supports up to three bus segments that are connected with network repeaters. The FC bus requires EOL termination at the end of each bus segment on the FC bus. The FC bus is a 3-wire system.

The FC bus terminations have pluggable screw terminal blocks that allow you to connect the bus devices in a daisy-chain configuration.

Note: The SHLD terminal on the FC bus terminal block is electrically isolated from ground and is provided as a convenient terminal for connecting the cable shield (if present) in a daisy-chain on the bus segment.

Table 4 provides the rules and limits for the FC bus. Metasys MS/TP devices generate less data traffic than third-party MS/TP devices and TEC26xx thermostats. Connecting third-party devices or TEC26xx thermostats to the FC bus increases data traffic, reduces bus performance, and reduces the number of devices that can be connected to the FC bus.

A network repeater has two device connections, which are independent of each other. Each device connection on the repeater is connected to a bus segment just like any other device connection on the segment, and a repeater device connection can be connected at the end of a bus segment or anywhere along the segment. When a repeater device connection is at the end of a bus segment, EOL termination must be enabled on that repeater device connection.

NAE (FC Bus Supervisor)

Ethernet Network

FEC (SA Bus Supervisor)

FC Bus

VMA (SA Bus

Supervisor)

SA Bus

IOM

Network Sensor

Network Sensors

SA Bus

Figure 7

Figure 7: Example of an MS/TP communication bus


3.2.2 SA BusThe SA bus connects NCEs, FECs, and VMA1600s (field controllers) to point devices such as IOMs, network thermostats, and network sensors on the FC bus. On an SA bus, an NCE, FEC, or VMA1600 is the bus supervisor. The SA bus does not support bus segments. On an SA bus, the minimum requirement is that EOL termination must be enabled on at least one device on the bus, and because an SA bus supervisor always has EOL termination enabled, this requirement is always met; however, for enhanced bus performance, it is preferable to have EOL termination enabled on the devices at each end of the SA bus. The SA-bus is a 4-wire or 6-wire system depending on the connector type used. The SA bus terminations can either have pluggable screw terminal blocks that allow you to connect the bus devices in a daisy-chain configuration or 6-pin RJ-type modular jack connections.

Table 5 provides the rules and limits for the SA bus. The SA bus is limited to 10 devices total to ensure good communication on the bus and is limited to four NS sensors because only four unique addresses can be set on the sensors. The SA bus is also limited by the total power consumption of the devices connected on the bus. SA bus applications are limited to a temporary power load of 210 mA. The best practice when configuring an SA bus is to limit the total available operating power consumption to 120 mA or less. Table 6 provides the power consumption of devices commonly connected to the SA bus.

Rules/Limits

General NAE55 series models can support up to two FC buses1.NAE45 series models can support one FC bus1.NAE35 series models can support one FC bus1 (but an NAE35 FC bus supports only half the number of devices that are supported on an FC Bus on an NAE45 or NAE55).NCE25 Series models can support one FC bus1.

Note: An FC port on an NAE/NCE can connect to only one bus segment on an FC bus. Only a daisy-chain topology is allowed (no T or Star topology configurations).

Number of Devices and Bus Segments

NCE25 models support 32 MS/TP devices (maximum) on an FC bus trunk and up to 3 bus segments.NAE45 and NAE55 models support the following device limits on an FC bus trunk:NAE35 models support half the number of devices that an NAE45 supports.When all of the devices connected on the FC bus are Metasys FECs, VMA1600s, and/or IOMs, the device and bus segment limits are as follows:• 100 devices total per FC bus (maximum)• 3 bus segments per FC bus (maximum)• 50 devices per bus segment (maximum, not to exceed 100 devices per FC bus)When one or more TEC-26xx Series thermostat or third-party MS/TP device2 is connected on the FC Bus, the device and bus segment limits are as follows:• 64 devices total per FC bus (maximum)• 3 bus segments per FC bus (maximum)• 32 devices per bus segment (maximum, not to exceed 64 devices per FC bus)

Bus segments on an FC bus are connected with repeaters (only). Up to two cascadedrepeaters may be applied to an FC bus (to connect three bus segments).

EOL Termination The EOL switch must be set to ON (or an EOL terminator installed) on the two deviceslocated at either end of each bus segment on an FC bus. The EOL switches must be set to OFF (or EOL termination disabled) for all other devices on the bus segment on an FC bus.

TABLE 4: FC BUS RULES AND LIMITS

Notes: 1. Refer to the Network Automation Engine (NAE) Product Bulletin (LIT-1201160) and the Network Controller

Engine Product Bulletin (LIT-12011283) for complete information on MS/TP bus support on NAE and NCE models.

2. If third-party devices are connected to the bus, the cable lengths should be reduced (if necessary) to match the third-party vendor recommendations.


IMPORTANT: The total power consumption on an SA bus is limited; do not exceed the SA bus power consumption limit. Exceeding the total power consumption limit can cause poor bus communication and devices to go offline.

Rules/Limits

General Each bus supervisor supports one SA bus (and each SA bus is a single segment).

Number of Devices and Bus Segments

An SA bus supports up to 10 devices.

Note: Only four Network Sensor addresses are available for use on an SA bus. In addition, the SA bus supervisor provides power for Network Sensors and some of the other devices connected on the bus. Exceeding the SA bus power limit can result in devices going offline and poor bus performance.

SA buses do not support repeaters.

SA buses do not support repeaters.

EOL Termination Each SA bus supervisor has integral (fixed ON) EOL termination, which typically provides sufficient EOL termination on an SA bus. Long SA bus runs or persistent communication problems on an SA bus may require EOL termination at the last device on the SA bus (in addition to the integral EOL termination at the SA bus supervisor).

TABLE 5: SA BUS RULES AND LIMITS

SA Bus Device Power Consumption on the SA Bus

Discharge Air Sensors (NS-DTN70x3-0) 12 mA

Network Sensors without display 13 mA

Network Sensors with display no RH 21 mA

Network Sensors with display and RH 27 mA

ZFR1811 Wireless Field Bus Router 90 mA

DIS1710 Local Controller Display 90 mA – may be a temporary load

BTCVT Wireless Commissioning Converter 90 mA – temporary load

Variable Speed Drives N/A (self powered)

IOM Series Controllers N/A (self powered)

Romutec® Modules N/A (self powered)

TABLE 6: POWER CONSUMPTION BY COMMON SA BUS DEVICES


3.2.3 End-of-Line Termination on the MS/TP BusDaisy-chained RS-485 networks typically require some type of End-of-Line (EOL) termination to reduce interference caused by signal reflection that occurs when data transmissions reach the end of a bus segment and bounce back on the segment. The high baud rates on MS/TP bus applications require robust EOL termination and strict adherence to the EOL termination rules.

The EOL termination requirements for the FC bus are different from the SA Bus requirements. Also, third-party MS/TP devices and TEC26xx Series thermostats have different EOL termination requirements from Metasys devices on the FC bus.

3.2.4 MS/TP Bus Cable Recommendation from JCIThe MS/TP bus supports much higher baud rates than the N2 bus. Higher baud rates make the MS/TP bus less fault tolerant and less immune to interference from inductive noise sources that may be present in the application environment.

For the best performance on MS/TP bus applications, 22 AWG stranded wire in a shielded cable with proper cable shield grounding is recommended. Other wire gauges and non-shielded cable can provide acceptable bus performance in many applications, especially applications that have short cable runs and low ambient inductive noise levels.

Table 7 provides cable recommendations for MS/TP applications.

3.2.5 SYSTIMAX Guidelines for FC busThe FC bus can be supported using SYSTIMAX PowerSUM, GSXL or GSX10D UTP cabling. The recommended solutions are GSXL and GSX10D since these are based on 23 AWG cables. The FC bus uses pairs 1 & 2 and links the NAE or NCE to FECs, VMA1600s, Input/Output Modules (IOMs), TEC26xx series thermostats, and Variable Speed Drives (VSDs). Table 8 provides the SYSTIMAX supported distances and Table 9 provides the assignment of signals to cable pairs.

The SYSTIMAX Power Separation Guidelines document shall be adhered to.

Bus and Cable Type Cable Type

Recommended FC Bus:SA Bus (Terminal Block):SA Bus (Modular Jack):

22 AWG Stranded, 3-Wire Shielded Twisted Pair Cable22 AWG Stranded, 4-Wire, Shielded Twisted Pair Cable26 AWG Solid, 6-Wire, Unshielded Twisted Pair Cable

Acceptable FC Bus: SA Bus (Terminal Block):

22 AWG Stranded, 3-Wire Unshielded Twisted Pair Cable22 AWG Stranded, 4-Wire Unshielded Twisted Pair Cable

TABLE 7: RECOMMENDED CABLES FOR FC AND SA BUSES


Bus Name Bus Layout PowerSUM, GigaSPEED XL, GigaSPEED X10D1

Maximum Length m (ft)

Number of Devices2

Number of Pairs Required

Sheath Sharing with Like Signal

FC bus (No Repeater)

Chained Devices and Chained Branches

1 segment1220 (4000) per segment

Up to 50/NAE3 2 YES

FC bus (2 Repeaters)


3 segments3660 (12000) per network

Up to 100/NAE3

50 per segment2 YES

TABLE 8: SYSTIMAX SUPPORTED DISTANCES FOR FC BUS

TABLE 9: ASSIGNMENT OF FC BUS SIGNALS TO CABLE PAIRS

Notes: 1. GSXL and GSX10D are the recommended solutions. 2. Please refer to Table 4 and consult JCI representatives for maximum number of devices that can be

daisy-chained together.3. When one or more TEC-26xx Series thermostat or third-party MS/TP device is connected on the FC bus,

the device and bus segment limits are as follows • 975 meter (3200 ft) per segment or 2925 meter (9600 ft) per network using repeaters • 64 devices total per FC bus (maximum) • 3 bus segments per FC bus (maximum) • 32 devices per bus segment (maximum, not to exceed 64 devices per FC bus)

Notes:

COM = Common or Signal Ground

S = Signal

3.2.5.1 FC Chained BranchesSince the individual segments of the FC bus cannot be star wired, each horizontal run (branch) must be wired in a daisy chain fashion as shown in Figure 8. Remember to account for the distance travelled by the signal in both directions on a branch, when calculating the overall maximum distance. Note that the VMA device is the last device on the FC bus in Figure 8.

Pair Number/Wire Colors/Pin Numbers

1 2 3 4

W-BL BL W-O O W-G G W-BR BR

FC bus +S –S COM COM

FC bus (shared sheath) +S –S COM COM +S –S COM COM


Horizontal cable

Outlet VP/VP360 Panel

Horizontal cable

NAE/ NCE

Second Floor

First Floor

Cop

per

Bac

kbon

e D

istr

ibut

ion

VMA (Last device EOL)

FEC

+S

–S

COM

W-BL & W-G

BL & G

W-O/O & W-BR/BR

+S

–S

COM

W-BL

BL

W-O/O

+S

–S

COM

W-BL

BL

W-O/O

VP/VP360 Panel

To NAE

1 2 3 4 1 2 3 4 Pair No. 1 2 3 4

To 2nd floor To outlet

Jumpers or patch cords

Figure 8

Figure 8: Chained branches for FC bus with shared sheath

3.2.5.2 FC Chained DevicesChained devices are typically used for zone coverage as depicted in Figure 9. It is possible to combine FC chained devices and FC chained branches in the same segment.


Horizontal cable NAE/NCE

(Last device EOL)

FEC

+S

–S

COM

W-BL

BL

W-O/O

VP/VP360 Panel

VMA

+S

–S

COM

W-BL

BL

W-O/O

+S

–S

COM

W-BL

BL

W-O/O

+S

–S

COM

W-G

G

W-BR/BR

+S

–S

COM

W-BL

BL

W-O/O

+S

–S

COM

W-G

G

W-BR/BR

+S

–S

COM

W-BL

BL

W-O/O

FEC

To NAE

1 2 3 4 1 2 3 4 Pair No.

To next FC device or repeater

To outlet


Figure 9

3.2.6 SYSTIMAX Guidelines for SA busThe SA bus can be supported using SYSTIMAX PowerSUM, GSXL or GSX10D UTP cabling. The recommended solutions are GSXL and GSX10D since these are based on 23 AWG cables. The SA bus uses pairs 1 & 2 and links the NCEs, FECs, and VMA1600s (field controllers) to point devices such as IOMs, network thermostats, and network sensors on the FC bus. Table 10 provides the SYSTIMAX supported distances and Table 11 provides the assignment of signals to cable pairs.

Figure 9: Chained devices for FC bus zone coverage

Bus Name Bus Layout PowerSUM, GigaSPEED XL, GigaSPEED X10D1

Maximum Length m (ft)

Number of Devices


SA bus Chained Devices and Chained Branches

1 segment293 (960) per segment2

Up to 10 2 2

Network Sensors and Bus Supervisor (FEC or VMA1600 supplying power to sensor) using bus cable connected to the SA bus screw terminal blocks

122 (400) N/A 2

Network Sensors using bus cables connected to the RJ-type modular jack

24 (80) N/A 2

TABLE 10: SYSTIMAX SUPPORTED DISTANCES FOR SA BUS

Notes: 1. GSXL and GSX10D are the recommended solutions. 2. Please refer to Table 5 and consult JCI representatives for maximum number of devices

that can be daisy-chained together.


TABLE 11: ASSIGNMENT OF SA BUS SIGNALS TO CABLE PAIRS

Notes: S = Signal COM = Common or Ground SA PWR = SA Power

3.2.6.1 SA Chained BranchesSince the individual segments of the SA bus cannot be star wired, each horizontal run (branch) must be wired in a daisy chain fashion as shown in Figure 10. Remember to account for the distance travelled by the signal in both directions on a branch, when calculating the overall maximum distance. Note that the IOM device is the last device on the SA bus in Figure 10 and JCI recommends that its EOL termination is enabled for best performance.

Figure 10: Chained branches for SA bus with shared sheath

Horizontal cable


Horizontal cable FEC

Second Floor

First Floor

Cop

per

Bac

kbon

e D

istr

ibut

ion

(Last device EOL recommended)

VP/VP360 Panel

+S

–S

COM

W-BL

BL

W-O

SA PWR O

W-BL & W-G

BL & G

W-O & W-BR

+S

–S

COM

SA PWR O & BR

IOM

Network Sensor

W-BL

BL

W-O

+S

–S

COM

SA PWR O

To FEC

1 2 3 4 1 2 3 4 Pair No. 1 2 3 4



Figure 10


1 2 3 4


SA bus +S –S COM SA PWR

SA bus (shared sheath) +S –S COM SA PWR +S –S COM SA PWR


3.2.6.2 SA Chained DevicesChained devices are typically used for zone coverage as depicted in Figure 11.

Figure 11: Chained devices for SA bus zone coverage

Horizontal cable

(Last device EOL)

VP/VP360 Panel

FEC

+S

–S

COM

W-BL

BL

W-O

SA PWR O

Network Sensor

+S

–S

COM

W-BL

BL

W-O

SA PWR O

+S

–S

COM

W-BL

BL

W-O

SA PWR O

+S

–S

COM

W-BL

BL

W-O

SA PWR O

IOM

+S

–S

COM

W-BL

BL

W-O

SA PWR O

Network Sensor

+S

–S

COM

W-G

G

W-BR

SA PWR BR

+S

–S

COM

W-G

G

W-BR

SA PWR BR

To FEC

1 2 3 4 1 2 3 4 Pair No.

To next SA device

To outlet


Figure 11


3.3 LON (LonWorks) NetworkLON is a standard open protocol developed by Echelon. It provides sensor and controller connectivity. Its applications are well defined allowing customers to find ‘pin compatible’ products across vendors. LON devices, however, require a single-sourced communication chip, the neuron, for node-to-node communication. LON also has a limited set of configuration tools available to configure the resident applications. LON devices are most prominent at the sensor and room controller layers.

The LON technology provides the components and tools required to design applications that distribute intelligence and control throughout a system. A central component in the LON product family is the Neuron chip, which contains the LonTalk protocol stack and a dedicated applications processor. When nodes are required to communicate over long distances, transceivers are used. The LON FTT-10A transceiver is a free topology device that provides a physical communication interface between a Neuron Chip and a LON twisted pair network. The FTT-10A is used to implement node-to-node communication, and may also be used as elements of repeaters and routers to extend networks. The FTT-10A Free Topology twisted pair transceiver supports star, bus, and loop wiring architectures. The FTT-10A transceiver uses transformer isolation and 78 kb/s differential Manchester coded data signals. Nodes equipped with the FTT-10A communicate via a twisted-pair cabling channel. The cabling channel may be comprised of multiple segments separated by physical layer repeaters. The FTT-10A transceiver may be used as an element of a physical layer repeater or router to extend the number of nodes and distances of the network. A free topology architecture allows virtually no topology restrictions.

CommScope IBIS supports cabling for the installation of JCI LON technology based systems using various SYSTIMAX PowerSUM, GSXL or GSX10D solutions and this is listed in Table 12. For more detailed design guidelines, please refer to the ‘CommScope IBIS LonWorks Design Guide’.

LON FTT-10A Free Topology Transceiver

Transceiver Rate (kb/s) Topology Nodes/Segment PowerSUM, GSXL, GSX10D (m)

Maximumnode-to-nodedistance

FTT-10A 78 Bus1 64 500 (900 m electrical length)

500 (900 m electrical length)

FTT-10A 78 Free2 64 450 250

TABLE 12: LON FTT-10A PARAMETERS AND SYSTIMAX SUPPORTED DISTANCES

Notes: 1 Doubly terminated bus; 3 meter stubs. SYSTIMAX implements this as star wiring with chained branches. 2 Requires one termination. SYSTIMAX implements this as star wiring with bridged branches.


Figure 12: Example of a N2 bus network

3.4 N2 Bus NetworkThe N2 bus is a modified RS-485 network that links Network Control Modules (NCMs), which reside in NCUs, to N2 bus devices such as ASCs, DCMs, Point Multiplex Modules (XBN, XRE, XRL, XRM) and XMs. The N2 bus uses a master/slave protocol, in which the master device, the NCM, initiates all communication with the N2 bus devices. See Figure 12.

The N2 bus can be extended using repeaters. The N2 repeater isolates and boosts the power of the N2 bus signal, which extends the range and increases the number of devices that can reside on the N2 bus. The repeater actually creates a new N2 bus segment. (A segment is an electrically continuous daisy-chained cable between repeaters or repeaters to End-of-Line [EOL].) In addition, the repeater electrically isolates the two segments. A maximum of two repeaters may be used in series, creating three N2 bus segments. Table 13 provides the N2 bus rules.

Please refer to ‘JCI N2 Communications Bus Technical Bulletin’ for more detail information on the N2 communications bus.

Rules/Maximums Allowed

General One or two N2 bus per NCM. Only daisy-chained devices.

Number of Devices 100 devices per NCM (60 to 200 TC-9100s). 50 devices per repeater. Two repeaters cascaded.

Line Length and Type

1520 m (5000 ft) between NCM to farthest N2 device before repeater is needed.4570 m (15000 ft) from NCM to farthest N2 device (three segments of 1520 m [5000 ft] each).2012 m (6600 ft) between two fiber modems.

Cable 26 AWG twisted pair or larger (solid or stranded, 22 AWG or heavier recommended).

Terminations Two switched EOL per segment (preferred).One switched EOL per segment (required).

TABLE 13: N2 BUS RULES

NCU/NCM

Ethernet Network

N2 Bus

ASC (DX9100)

ASC (UNT)

Thermostat

Figure 12


3.4.1 End-of-Line (EOL)The N2 bus requires a minimum of one and a maximum of two configured End-of-Line (EOL) devices per N2 segment. The NCMs, DCM, XBN, XRE, XRL, XRM, ILC, IFC, D600, and repeaters have selectable EOL switches (i.e. switch-terminating). Typically, the NCM and repeater are designated as an EOL. The repeater has two EOL switches (A and B Line). AHU, LCP, UNT, and VAVs do not need EOL devices, because they terminate automatically (i.e. self-terminating).

3.4.2 SYSTIMAX Guidelines for N2 busThe N2 bus can be supported using SYSTIMAX PowerSUM, GSXL or GSX10D UTP cabling. The N2 bus uses pairs 1 & 2 and links the NCMs to N2 devices (ASCs, XMs, DCMs, etc). All devices residing on the N2 bus use wire-insert screw-down connection terminals. These screw terminals will accept 23/24-AWG wire. However, for a quality connection, use crimp-on pins. When inserting multiple wires into a terminal, place the conductors flat and side-by-side. This allows pressure to be placed on all the conductors.

Note: Do not twist the wires together, as twisted wires have the tendency to pull out.

Table 14 provides the SYSTIMAX supported distances and Table 15 provides the assignment of signals to cable pairs. Up to 50 N2 devices can be located on a segment with a total length of 1520 m (5000 ft). A maximum of two repeaters can be used in series on an N2 bus, creating a maximum of 100 N2 devices per NCM. The N2 devices can be interconnected via both chained branches (see Figure 13) and chained devices (see Figure 14).

Bus Name Bus Layout PowerSUM, GSXL, GSX10D Maximum Length m (ft)

Maximum Number of Devices


SheathSharingwith Like Signal

N2 bus(No Repeater)


1 segment1520 (5000) per segment

50/NCM 2 YES

N2 bus(1 Repeater)


2 segments1520 (5000) per segment

100/NCM 50 per segment

2 YES

TABLE 14: SYSTIMAX SUPPORTED DISTANCES FOR N2 BUS

TABLE 15: ASSIGNMENT OF SIGNALS TO CABLE PAIRS


1 2 3 4


N2 bus N2 bus (shared sheath)

N2+N2+

N2–N2–

REFREF

REFREF N2+ N2– REF REF

AOAI

SS

GNDGND

AOAI

SS

GNDGND

Power +AC/DC –AC/DC

Notes: REF = Reference or Signal Ground, S = Signal, GND = Ground (Common or Reference)


3.4.2.1 N2 Chained BranchesSince the individual segments of the N2 bus cannot be star wired, each horizontal run (branch) must be wired in a daisy chain fashion as shown in Figure 13. Remember to account for the distance travelled by the signal in both directions on a branch, when calculating the overall maximum distance. Note that the AHU device is the last device on the N2 bus in Figure 13.

Figure 13: Chained branches for N2 bus with shared sheath

3.4.2.2 N2 Chained DevicesChained devices are typically used for zone coverage as depicted in Figure 14. It is possible to combine N2 chained devices and N2 chained branches in the same segment.

Horizontal cable


Horizontal cable

NCU/NCM

Second Floor

First Floor

Cop

per

Bac

kbon

e D

istr

ibut

ion

AHU (Last device EOL)

VAV

N2+

N2–

Ref

W-BL & W-G

BL & G

W-O/O & W-BR/BR

N2+

N2–

Ref

W-BL

BL

W-O/O

N2+

N2–

Ref

W-BL

BL

W-O/O

VP/VP360 Panel

To NCU

1 2 3 4 1 2 3 4 Pair No. 1 2 3 4



Figure 13

Horizontal cable

OutletVP/VP360 Panel

Horizontalcable

NCU/NCM

Second Floor

First Floor

Cop

per

Bac

kbon

eD

istr

ibut

ion

AHU(Last deviceEOL)

VAVVAVVAAVAVVAAV

N2+

N2–

Ref

W-BL & W-G

BL & G

W-O/O & W-BR////BR

N2+

N2–

Ref

W-BL

BL

W-O/O

N2+

N2–

Ref

W-BL

BL

W-O/O

VP/VP360Panel

ToTToTToTT NCU

1 2 3 4 1 2 3 4Pair No. 1 2 3 4

ToToTToT 2nd floorToToTToT outlet


Figure 13

Horizontal cable


Horizontal cable

NCU/NCM

Second Floor

First Floor

Cop

per

Bac

kbon

e D

istr

ibut

ion

AHU (Last device EOL)

VAV

N2+

N2–

Ref

W-BL & W-G

BL & G

W-O/O & W-BR/BR

N2+

N2–

Ref

W-BL

BL

W-O/O

N2+

N2–

Ref

W-BL

BL

W-O/O

VP/VP360 Panel

To NCU

1 2 3 4 1 2 3 4 Pair No. 1 2 3 4



Figure 13


Figure 14: Chained devices for N2 bus zone coverage

3.4.2.3 Calculating the Number of Chained Branches per N2 SegmentIn a worst case application the distance from the patch panel to the ASC device would be 100 m (328 ft). Since the branches are chained at the patch panel, the N2 signal must travel out to the ASC cluster, then back to the patch panel, and then on to the next cluster of ASCs. Consequently, the distance travelled for each branch is

2 x 100 m = 200 m (656 ft)

The maximum distance/segment is 1520 m (5000 ft).

1520/200 m = 7.6 or 7 full branches 200 m x 7 branches = 1400 m (4592 ft)

It is possible to connect an eighth branch, provided the signal does not have to return to the patch panel. This eighth branch would give an N2 segment length of:

1400 m + 100 m = 1500 m (4920 ft)

Note: The N2 bus may also extend over the riser/backbone cabling system.

Horizontal cable NCU/NCM

(Last device EOL)

VAV

N2+

N2–

Ref

W-BL

BL

W-O/O

N2+

N2–

Ref

W-BL

BL

W-O/O

VP/VP360 Panel

To NCU

1 2 3 4 1 2 3 4 Pair No.

To next N2 device or repeater

To outlet

AHU

UNT

N2+

N2–

Ref

W-BL

BL

W-O/O

N2+

N2–

Ref

W-BL

BL

W-O/O

N2+

N2–

Ref

W-G

G

W-BR/BR

N2+

N2–

Ref

W-BL

BL

W-O/O

N2+

N2–

Ref

W-G

G

W-BR/BR


Figure 14


3.5 Lightning Protection CircuitrySurge protection is recommended if any of the buses are wired between buildings using copper cabling, especially in areas with above average thunderstorm activity. The protection is provided by a voltage surge protector, which is installed on the bus near the device. One surge protector is required at each location where a bus enters a building from the outside.

Please contact a JCI representative for more detailed information about surge protection.

3.6 Input/Output Device GuidelinesASCs support both digital and analog I/O devices. The primary considerations for digital device distances are usually the electrical parameters (in other words, resistance, current, and voltage) and signal attenuation. In most cases, the analog device distances are not limited by interface or signal attenuation, but by potential interference sources such as other control signals or AC power transients. For these reasons, the overall limit for all endpoint devices (analog and digital) of 200 m (656 ft) is imposed. If there is any reason to suspect a particularly noisy environment or cable route, then an alternate cable route or additional routing precautions should be taken.

3.6.1 Analog Inputs

3.6.1.1 Temperature SensorsTemperature sensors are connected to controllers by 24-AWG UTP cable, which changes resistance with the environmental temperature. Since the temperature sensors are resistive and the sensors’ resistance changes with the temperature of the environment being measured, it is important to determine the measurement error due to temperature change in the cable. This error can be linearly compensated for in the Johnson Control software, by applying an offset value to the temperature device being monitored. Temperature measurements are usually performed with error less than or equal to ±0.5 K. Table 16 lists sensitivities in ohm per Kelvin (Ω/K) for analog input passive sensors.

Sensor Sensor Sensitivity

Thin Film or Nickel Wire 5.4 Ω/K

Platinum 0.4 or 4 Ω/K

Silicon 7.7 Ω/K

TABLE 16: SENSOR SENSITIVITY MEASURED IN Ω/K


Two factors contribute to the measurement error introduced by a cable:

Static error due to cable resistance•

Dynamic error due to change in cable resistance with temperature•

Static error, expressed in degrees Kelvin per 100 m (328 ft) of a cable pair is calculated by dividing cable resistance by sensor sensitivity (see Table 16) at a given temperature.

Example: The resistance of the 24-AWG UTP cable pair is 18.76 ohm per 100 m at 20°C (68°F), so the static error introduced by the cable at this temperature in the nickel sensor is:

18.76 ohm per 100 m /5.4 ohm/K = 3.47 K per 100 m of cable

The static error is corrected by an offset adjustment during installation. Once this adjustment has been made, there is no static error (and no measurement error at a constant temperature) for the sensors using 100 m (328 ft) of 24-AWG UTP cable.

The temperature coefficient for copper wire is 0.393% per °C @ 20°C. Hence, the resulting resistance, RT for a copper conductor at a given temperature, T°C is given by

RT = R20 * [1 + 0.00393*(T-20)]

where

R20 is the resistance at 20°C

Table 17 provides the maximum DC resistance of a 0.511 mm (24 AWG) copper conductor at various temperatures.

Note: With an offset adjustment applied, the temperature error is based on the sensor accuracy and dynamic error (caused by resistance change in the cable over a range of temperatures). If more accuracy is required throughout the range, please consult a JCI representative.

Resistance in the wire between a resistive temperature sensor and a controller introduces a temperature error into the sensor circuit. Both the Nickel (Ni) and Platinum (Pt) type resistive sensors experience errors in their temperature readings due to resistance in the sensor cable. The amount of resistance (temperature error) increases with an increase in wire length and/or a decrease in wire diameter (wire gauge).

To minimize sensor temperature error due to field wiring, the total resistance of all resistive sensor wiring should be less than 3 ohms (which results in approximately a 1.0 °F offset in Nickel sensors).

Table 18 provides the maximum wire lengths for sensor to controller circuits.

Maximum Operating Temperature Maximum DC Resistance (ohms per meter)

20°C 0.0938

30°C 0.0975

40°C 0.1012

50°C 0.1049

60°C 0.1085

TABLE 17: MAXIMUM DC RESISTANCE FOR 0.511 MM (24 AWG) COPPER CONDUCTOR


System Controller Maximum Controller Source Current (mA)

Maximum Resistance(ohm)

Maximum 18-/24-AWG Cable Length in m (ft)

UNT @ 0 – 10 VDC 10 1K – 10M 61 – 305 (200 – 1000)

VAV @ 0 – 10 VDC 10 1K – 10M 61 – 305 (200 – 1000)

AHU (current)@ 18 VDC max

AHU (voltage)0 – 10 VDC

0 – 20 mA

0 – 20 mA

900

900

305 (1000)

305 (1000)

DX (current)@ 10VDC max

DX (voltage)0 – 10 VDC

0 – 20 mA

0 – 20 mA

500

1K – 10M

152 (500)

30 – 152 (100 – 1000)

FEC, IOM, VMA(Configurable Outputs – configured for current output)

10 500 – 5000K 30 – 1520 (100 – 5000)

Wiring Configuration Distance in m (ft)

2-wire (locally powered) 30 (100)

TABLE 20: MAXIMUM CABLE RESISTANCE

TABLE 19: MAXIMUM DISTANCE FOR 2% MEASUREMENT ERROR

Wire Gauge, mm (AWG) Ohms/305 m (Ohms/1000 ft) Maximum one way distance, m (ft)

0.643 (22) 16.2 28.3 (93)

0.511 (24) 25.7 17.7 (58)

0.404 (26) 41.0 11.3 (37)

TABLE 18: MAXIMUM WIRE LENGTHS FOR SENSOR TO CONTROLLER CIRCUITS

3.6.1.2 Powered SensorsTable 19 gives the maximum distance in meters (feet) for a 2% measurement error.

3.6.2 Analog OutputsTo ensure a maximum voltage deviation of ±100 mV at the user end of a cable and maximum rated load, refer to Table 20, which lists the maximum controller current allowed.

If the user current is not known, then use the maximum controller current to calculate voltage deviation at the user end of the cable for these systems.


System Controller Maximum Voltage at Controller (V)

Maximum Controller Current (mA)

Maximum 24-AWG UTP Cable Lengthin m (ft)

AHU, VAV, UNT, DX-9100, LCP, FEC, IOM, VMA

24 VAC 50 – 500 30 (100)

TABLE 21: CONTROLLER DIGITAL OUTPUT PARAMETERS

3.6.3 Digital OutputsTable 21 lists the maximum controller current allowed and the minimum controller voltage guaranteed. If the user current is not known, then use the maximum controller current.

4.0 ReferencesPlease contact your local CommScope or JCI representative for the documents listed below. Most of these documents can also be obtained from the respective company website. The latest issue shall be used.

1. JCI MS/TP Communications Bus Technical Bulletin (LIT-12011034)

2. JCI Network Automation Engine (NAE) Product Bulletin (LIT-1201160)

3. JCI Network Controller Engine Product Bulletin (LIT-12011283)

4. SYSTIMAX Performance Specification, Volume 1 – SYSTIMAX Applications

5. CommScope IBIS LonWorks Design Guide

6. Power Separation Guidelines for SYSTIMAX SCS Installations

www.commscope.comVisit our Web site or contact your local CommScope representative for more information. © 2011 CommScope, Inc. All rights reserved.

All trademarks identified by ® or ™ are registered trademarks or trademarks, respectively, of CommScope, Inc.

This document is for planning purposes only and is not intended to modify or supplement any specifications or warranties relating to CommScope products or services.

12/09

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