Trane Tracer MP503 Installation and operating instructions

Tracer® MP503 Input/Output Module
Installation, Operation, and Maintenance
April 2020 CNT-SVX09E-EN
SAFETY WARNING
Only qualified personnel should install and service the equipment. The installation, starting up, and servicing of
heating, ventilating, and air-conditioning equipment can be hazardous and requires specific knowledge and training.
Improperly installed, adjusted or altered equipment by an unqualified person could result in death or serious injury.
When working on the equipment, observe all precautions in the literature and on the tags, stickers, and labels that are
attached to the equipment.

©2020 Trane CNT-SVX09E-EN
Introduction
Warnings, Cautions, and Notices
Safety advisories appear throughout this manual as required. Your personal safety and the proper
operation of this machine depend upon the strict observance of these precautions.
The three types of advisories are defined as follows:
WARNING Indicates a potentially hazardous situation which, if not avoided, could result in
death or serious injury.
CAUTIONsIndicates a potentially hazardous situation which, if not avoided, could result in
minor or moderate injury. It could also be used to alert against unsafe practices.
NOTICE Indicates a situation that could result in equipment or property-damage only
accidents.
Copyright
This document and the information in it are the property of Trane, and may not be used or
reproduced in whole or in part without written permission. Trane reserves the right to revise this
publication at any time, and to make changes to its content without obligation to notify any person
of such revision or change.
Trademarks
All trademarks referenced in this document are the trademarks of their respective owners.
Agency Listings and Compliance
The European Union (EU) Declaration of Conformity is available from your local Trane®office.
Revision History
CNT-SVX09D-EN
• Added the Agency Listings and Compliance statement.
CNT-SVX09C-EN
• Cost Savings: Update to mount plate and metal enclosure to remove metal screw/nut and use
plastic PEM nut. Change to figure illustrations.

Table of Contents
CNT-SVX09E-EN 3
Overview and Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Product Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Storage Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Operating Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Agency Listing/Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
General Wiring Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Input/Output Terminal Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
AC Power Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Communication Link Wiring and Addressing . . . . . . . . . . . . . . . . . . . . . . . . . 9
Mounting the Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Location Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Operating Environment Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Mounting Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Applications for the MP503 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Binary Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Thermistor Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
0–20 mA Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
0–10 Vdc Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Wiring Requirements and Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Network Variable Bindings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Network Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Binding Network Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
MP503 Bindings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Receiving Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Sending Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Examples of Network Variable Bindings . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Example 1: Display Sensor Readings from a MP503 on a MP581 Operator
Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Example 2: Display Sensor Readings from a MP503 on Two Different
MP581 Operator Displays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Example 3: Control a Binary Output on the MP503 from a MP581 . . . . . 18
Example 4: Use a Sensor Reading on a MP503 to Control a Pump VFD on a
MP581 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Table of Contents
4CNT-SVX09E-EN
Status Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
MP503 Circuit Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Service Pin Button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Interpreting LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Red Service LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Green Status LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Yellow LonTalk LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Binary Output LEDs (4 Green) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Initial Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Troubleshooting Binary Output (Relay Output) . . . . . . . . . . . . . . . . . . . . . . 24
Troubleshooting Universal Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

CNT-SVX09E-EN 5
Overview and Specifications
This guide provides installation and configuration information for the Tracer™ MP503 input/output
(I/O) module, as well as a description of its operations. The overview includes a product description,
specifications, and descriptions of additional components needed in some MP503 applications.
Product Description
The MP503 I/O module is a field-installed device used to monitor inputs and control binary outputs.
The module has four universal inputs that can be configured as binary, thermistor, 0–20 mA, or 0–
10 Vdc, as well as four binary outputs.
Storage Environment
If a MP503 I/O module is to be stored for a substantial amount of time, store it in an indoor
environment that meets the following requirements:
• Temperature: –40° to 185°F (–40° to 85°C)
• Relative humidity: 5–95%, non-condensing
Operating Environment
Operate a MP503 I/O module in an environment that meets the following requirements:
• Temperature: –40°F to 158°F (–40°C to 70°C)
• Relative humidity: 5–95%, non-condensing
Dimensions
Plastic Cover Model
• Height: 5.375 in. (137 mm)
• Width: 6.875 in. (175 mm)
• Depth: 2 in. (51 mm)
Metal Cover Model
• Height: 9.0 in (25 mm)
• Width: 10.37in. (263 mm)
• Depth: 2.25 in. (58 mm)
Clearances
For wiring, ventilation, and maintenance, provide the following minimum clearances for the
MP503:
Plastic Cover Model
• Front: 4.0 in. (102 mm)
• Each side: 1.0 in. (25 mm)
• Top and bottom: 4.0 in. (102 mm)
Metal Cover Model
• Front: 24.0 in. (610 mm)
• Each side: 2.0 in. (51 mm)
• Top and bottom: 1.0 in. (25 mm)

6CNT-SVX09E-EN
Overview and Specifications
Power
The transformer must meet the following minimum requirements for the controller and its output
devices:
• 19–30 Vac (24 Vac nominal)
• 50/60 Hz
• 9 VA and 12 VA maximum per binary output utilized
Agency Listing/Compliance
CE—Immunity:
EMC Directive 89/336/EEC
EN 50090-2-2:1996
EN 50082-1:1997
EN 50082-2:1995
EN 61326-1:1997
CE—Emissions:
EN 50090-2-2:1996 (CISPR 22) Class B
EN 50081-1:1992 (CISPR 22) Class B
EN 55022:1998 (CISPR 22) Class B
EN 61326-1:1997 (CISPR 11) Class B
UL and C-UL listed:
Energy Management Equipment—PAZX (UL 916)
UL 94-5V (UL flammability rating for plenum use)
FCC Part 15, Subpart B, Class B

CNT-SVX09E-EN 7
Overview and Specifications
Figure 1.
4 in.
(102 mm)
1 in.
(25 mm)
5.625 in.
(143 mm)
5.375 in. (137 mm)
1 in.
(25 mm)
6.31 in.
(160 mm)
4 in.
(102 mm)
4 in.
(102 mm)
2 in. (51 mm)
6.875 in.
(175 mm)
Clearances
Dimensions
MP503 plastic cover model dimensions and clearances
Figure 2. MP503 metal cover model dimensions and clearances
1 in. 
(25 mm)
9 in. 
(229 mm)
2 in. 
(51 mm)
24 in. 
(610 mm)
10.37 in.
(263 mm)
width with cover
1 in. 
(25 mm)
2.25 in. 
(58 mm)
Clearances
Dimensions
2 in. 
(51 mm)
9 in. 
(229 mm)
6.5 in. 
(165 mm)
1.875 in. 
(48 mm)
7 in. 
(178 mm)
1 in. 
(25 mm)
10.25 in. 
(260 mm)
width without cover

8CNT-SVX09E-EN
General Wiring Information
This section provides information about the following:
• Input/output terminal wiring
• AC power wiring
• Communication link wiring and addressing
Input/Output Terminal Wiring
• All input/output terminal wiring for the MP503 must meet the following requirements:
• All wiring must comply with the National Electrical Code™ (NEC) and local codes.
• Use only 18 AWG twisted-pair wire with stranded, tinned-copper conductors (Trane
recommends shielded wire).
• Binary output wiring must not exceed 1000 ft (300 m).
• Binary input and 4–20 mA input wiring must not exceed 1000 ft (300 m).
• Thermistor input and 0–10 Vdc input wiring must not exceed 300 ft (100 m).
Important:

Do not run input/output wires in the same wire bundle with any ac power wires.
For more details about wiring, refer to the section, “Applications for the MP503,” p. 11.
AC Power Wiring
CAUTION
Equipment Damage!
To prevent equipment damage, do not share 24 Vac between devices.
CAUTION
Equipment Damage!
Complete input/output wiring before applying power to the MP503. Failure to do so may cause
damage to the device or power transformer due to inadvertent connections to power circuits.
WARNING
Hazardous Voltage!
Disconnect all electric power, including remote disconnects before servicing. Follow proper
lockout/tagout procedures to ensure the power can not be inadvertently energized. Failure to
disconnect power before servicing could result in death or serious injury.
WARNING
Hazardous Voltage!
Ensure that the 24 Vac transformer is properly grounded. Failure to do so could result in death
or serious injury and/or damage to equipment.
The recommended wire for ac power is 16 AWG (1.3 mm2)copper wire. All wiring must comply with
National Electrical Code and local codes. The ac power connections are in the top left corner of the
MP503 as shown Figure 3.

CNT-SVX09E-EN 9
General Wiring Information
Figure 3. Connecting ac power wires to the module
H
N
24 Vac
transformer
Line
voltage
Use a UL-listed Class 2 power transformer supplying a nominal 24 Vac (20–30 Vac). The
transformer must be sized to provide adequate power to the MP503 (10 VA) and to the output
devices [including relays], to a maximum of 12 VA per output utilized. The MP503 may be powered
by an existing transformer integral to the controlled equipment, provided the transformer has
adequate power available and proper grounding is observed.
Communication Link Wiring and Addressing
The MP503 communicates with the BAS and with other devices through a LonTalk®
communication link.
Important:

For important instructions on network wiring, refer to the Tracer Summit™
Hardware and Software Installation Guide (BMTX-SVN01).
Wiring for the communication link must meet the following requirements:
• All wiring must comply with the National Electrical Code and local codes.
• 22 AWG Level 4 un-shielded communications wire recommended for most Comm5
installations.
• Termination resistors are required for wiring LonTalk devices communicating on a network. For
important instructions on using termination resistors for LonTalk applications, refer to the
Tracer Summit Hardware and Software Installation Guide (BMTX-SVN01).
Each MP503 has a unique 12-character alphanumeric device address for communicating on a BAS
network. This address, referred to as a Neuron ID, is assigned in the factory before the product is
shipped. Each device can be identified by viewing its unique Neuron ID, which is on a printed label
attached to the circuit board of the device. Additional adhesive-backed, peel-off Neuron ID labels
are tethered to the device for placing on mechanical prints or unit location worksheets. The Neuron
ID will appear when communication is established with a service tool (such as the Rover™ service
tool) or a BAS. An example Neuron ID is 00-01-64-1C-2B-00.

10 CNT-SVX09E-EN
Mounting the Module
This Section provides information about the following:
• Location recommendations
• Operating environment requirements
• Mounting recommendations
Location Recommendations
Trane recommends locating the MP503:
• Near the controlled equipment to reduce wiring costs
• Where it is easily accessible for service personnel
• Where public access is restricted to minimize the possibility of tampering or vandalism
Operating Environment Requirements
Operate the MP503 in an environment that meets the following requirements:
• Temperature: –40°F to 158°F (–40°C to 70°C)
• Relative humidity: 5–95%, non-condensing
Mounting Recommendations
Important:

Leave the cover on when mounting the MP503 to avoid the possibility damaging the
circuit board during installation.
Mounting recommendations are as follows:
• Mount the module in any direction, other than with the front of the cover facing downward.
• Mount using the two 3/16 in. (4.8 mm) radius mounting holes provided (refer to Figure 4).
Mounting fasteners are not included.
• Attach the module securely so it can withstand vibrations of associated heating, ventilating,
and air-conditioning (HVAC) equipment.
• If the module is mounted in a small enclosed compartment, complete all wiring connections
before securing the module in the compartment.
Figure 4. Mounting the MP503

CNT-SVX09E-EN 11
Applications for the MP503
The MP503 is a field-installed device that is used to monitor inputs and control binary outputs. The
module has four (4) configurable inputs and four (4) binary outputs. This section provides
information about the function of inputs and outputs and examples of wiring applications for
MP503.
Inputs
The MP503 has four (4) inputs. Each input can be configured (in any combination) as:
•Binary
•Thermistor
•0–20mA
• 0–10 Vdc.
The factory-default input type is a thermistor. To change the configuration of the input, use the
device plug-in and a service tool, such as the Rover service tool. No jumpers need to be set on the
circuit board.
Binary Inputs
When an input is configured as binary, the MP503 equates a signal of 0 Vac with open contacts and
24 Vac with closed contacts.
Thermistor Inputs
Thermistor inputs are used to measure temperature. They must be Trane 10kW (at 25°C)
thermistors. Any Trane zone temperature sensor can be connected to the MP503; however, the
module will not recognize the setpoint thumbwheel or fan speed switch that appears on some
sensors.
0–20 mA Inputs
Many common sensors, such as humidity, pressure, and flow sensors, provide a 4–20 mA output.
Any of these types of sensors can be connected to an input on the MP503 and configured for 0–
20 mA.
Important:

Because most sensors have 4–20 mA outputs rather than 0–20 mA outputs, some
scaling is required. The scaling cannot be done on the MP503. The MP503 transmits
the raw mA reading.
To power these sensors, 24 Vdc is available from the MP503 circuit board (refer to Figure 5, p. 12).
0–10 Vdc Inputs
The MP503 can read a value from a sensor that provides a 0–10 Vdc signal.
Important:

When using a sensor with a smaller range (such as 2–10 Vdc or 6–9 Vdc), some
scaling is required. The scaling cannot be done on the MP503. The MP503 transmits
the raw voltage reading.
To power these sensors, 24 Vdc is available from the MP503 circuit board (refer to Figure 5, p. 12).

12 CNT-SVX09E-EN
Applications for the MP503
Outputs
The binary outputs are Form A single-pole, single-throw (SPST) relay outputs. These relays switch
24 Vac and are not dry contacts.
Important:

A pilot relay is required for any application requiring dry contacts. Relays connected
to the binary outputs on the module cannot exceed 12 VA or 0.5 A current draw at
24 Vac.
Wiring Requirements and Options
Figure 5 shows the wiring of each type of input on the MP503 and the wiring for a typical binary
output.
Figure 5. Input/output terminal wiring for the MP503
H
Typical relay on/off
Not
used
In
LonTalk 
communication link
Out
24 Vac
N
Typical relay on/off
Typical relay on/off
Typical relay on/off
–
+
–
+GND
Typical
thermistor
sensor
Typical 2-wire 4–
20 mA sensor
Typical 3-wire
0–10 Vdc sensor
Typical
binary
switching
device
Typical relay on/off

CNT-SVX09E-EN 13
Network Variable Bindings
The LonTalk communication protocol allows data to be shared between devices (either as stand-
alone or with a BAS) on a LonTalk network as is referred to as peer-to-peer communication. An
example of peer-to-peer communication would be when two or more devices are serving the same
space, share data (such as a temperature reading) without having to pass the data through a BAS.
Network variables are used to share data between devices. The method used to direct data from
one device to another is called network variable binding, or just binding. A network variable output
from one device is bound to a network variable input on another device. An output variable from
one device can be bound to input variables on many other devices.
This section provides information about how to use network variable bindings in MP503
applications.
Network Variables
Each network variable is a standard type. This standard type is referred to as a standard network
variable type (SNVT, pronounced snivet). To bind two variables together, the variables must be the
same type of network variable. For example, an output of type SNVT_temp_p can only be bound
to an input of type SNVT_temp_p. For more information about SNVTs, refer to www.lonmark.org.
Binding Network Variables
Important:

Only LonTalk devices can use network variable binding. Devices on other
communication links do not have this capability.
BAS communication typically does not require the use of network variable binding because a
Tracer Summit BCU automatically binds to the proper data in a device. However, communication
speed can be increased between two devices by binding their data rather than having the BAS read
the information from one device, and then broadcasting it to another.
Use the Rover™ service tool to create bindings (refer to the Rover Operation and Programming
Guide (EMTX-SVX01).
MP503 Bindings
The principal uses of an MP503 are to gather data (sensor readings) for use by a BAS or peer device
and to allow a BAS or peer device to control MP503 binary outputs. Therefore, the use of bindings
is very important in MP503 applications.
The following examples in this section illustrate some common applications in which bindings are
used with the MP503.

14 CNT-SVX09E-EN
Network Variable Bindings
Receiving Data
A network variable input (nvi) receives data from other devices on the LonTalk network. Network
variable inputs (including their SNVTs) that are commonly used in MP503 bindings are shown in
Table 1
Table 1. Tracer MP503 network variable inputs
• The requested state of binary output 1.
• Bind to this nvi to controlthe binary outputfrom another device on the
network.
• The requested state of binary output 2.
• Bind to this nvi to controlthe binary outputfrom another device on the
network.
• The requested state of binary output 3.
• Bind to this nvi to controlthe binary outputfrom another device on the
network.
• The requested state of binary output 4.
• Bind to this nvi to controlthe binary outputfrom another device on the
network.
Sending Data
A network variable output (nvo) sends data to other devices on the LonTalk network. The network
variable outputs (including their SNVTs) that are commonly used in MP503 bindings are shown in
Table 2.
Variable Name Data Type Description
nviBOP1Request SNVT_switch Binary Output 1 Request:
nviBOP2Request SNVT_switch Binary Output 2 Request:
nviBOP3Request SNVT_switch Binary Output 3 Request:
nviBOP4Request SNVT_switch Binary Output 4 Request:
Table 2. Tracer MP503 network variable outputs
Variable name Data type Description
nvoTemperature1 SNVT_temp_p Universal Input 1 Status Output:
• Indicates the value of universal input 1 if it is configured
as thermistor.
• If universal input 1 is not configured as thermistor, this
output is invalid.
nvoTemperature2 SNVT_temp_p Universal Input 2 Status Output:
• Indicates the value of universal input 2 if it is configured
as thermistor.
• If universal input 2 is not configured as thermistor, this
output is invalid.
nvoTemperature3 SNVT_temp_p Universal Input 3 Status Output:
• Indicates the value of universal input 3 if it is configured
as thermistor.
• If universal input 3 is not configured as thermistor, this
output is invalid.
nvoTemperature4 SNVT_temp_p Universal Input 4 Status Output:
• Indicates the value of universal input 4 if it is configured
as thermistor.
• If universal input 4 is not configured as thermistor, this
output is invalid.

CNT-SVX09E-EN 15
Network Variable Bindings
nvoBIP1Status SNVT_switch Universal Input 1 Status Output:
• Indicates the value of universal input 1 if it is configured
as binary.
• If universal input 1 is not configured as binary, this output
is invalid.
nvoBIP2Status SNVT_switch Universal Input 2 Status Output:
• Indicates the value of universal input 2 if it is configured
as binary.
• If universal input 2 is not configured as binary, this output
is invalid.
nvoBIP3Status SNVT_switch Universal Input 3 Status Output:
• Indicates the value of universal input 3 if it is configured
as binary.
• If universal input 3 is not configured as binary, this output
is invalid.
nvoBIP4Status SNVT_switch Universal Input 4 Status Output:
• Indicates the value of universal input 4 if it is configured
as binary.
• If universal input 4 is not configured as binary, this output
is invalid.
nvoCurrent1 SNVT_amp_mil Universal Input 1 Status Output:
• Indicates the value of universal input 1 if it is configured
as 0–20 mA.
• If universal input 1 is not configured as 0–20 mA, this
output is -3276.8.
nvoCurrent2 SNVT_amp_mil Universal Input 2 Status Output:
• Indicates the value of universal input 2 if it is configured
as 0–20 mA.
• If universal input 2 is not configured as 0–20 mA, this
output is -3276.8.
nvoCurrent3 SNVT_amp_mil Universal Input 3 Status Output:
Indicates the value of universal input 3 if it is configured as
0–20 mA.
If universal input3 is not configured as 0–20 mA, this output
is -3276.8.
nvoCurrent4 SNVT_amp_mil Universal Input 4 Status Output:
• Indicates the value of universal input 4 if it is configured
as 0–20 mA.
• If universal input 4 is not configured as 0–20 mA, this
output is -3276.8.
nvoVolts1 SNVT_volt Universal Input 1 Status Output:
• Indicates the value of universal input 1 if it is configured
as 0–10 Vdc.
• If universal input 1 is not configured as 0–10 Vdc, this
output is -3276.8.
nvoVolts2 SNVT_volt Universal Input 2 Status Output:
• Indicates the value of universal input 2 if it is configured
as 0–10 Vdc.
• If universal input 2 is not configured as 0–10 Vdc, this
output is -3276.8.
nvoVolts3 SNVT_volt Universal Input 3 Status Output:
• Indicates the value of universal input 3 if it is configured
as 0–10 Vdc.
• If universal input 3 is not configured as 0–10 Vdc, this
output is -3276.8.
Table 2. Tracer MP503 network variable outputs (continued)
Variable name Data type Description

16 CNT-SVX09E-EN
Network Variable Bindings
Examples of Network Variable Bindings
The following examples show four (4) common uses of bindings in MP503 applications.
Example 1: Display Sensor Readings from a MP503 on a MP581 Operator Display
In this example, four different sensors are connected to a MP503. A thermistor reading the outside
air temperature is connected to universal input 1 on the MP503. A 4–20 mA sensor reading the
outside air humidity is connected to universal input 2. Two binary inputs from a fire panel (Alarm
Status and Fire Panel Trouble) are connected to universal input 3 and universal input 4,
respectively. An MP581 is on the same LonTalk link as the MP503. The MP581 is controlling an air-
handling unit (AHU). The outside air enthalpy is required to control the economizer on the AHU.
The building operator also wants to know the outside air temperature and humidity, so those
values should be displayed on the operator display of the MP581. The location of the outside air
sensors make it convenient to wire those points to the MP503.
Use bindings to allow the economizer control in the MP581 to calculate outside air enthalpy and
to display the four inputs from the MP503 on the operator display of the MP581. Figure 6 shows
the LonTalk network for this example.
Figure 6. LonTalk network for example 1
®
LonTalk link
Tracer MP503
Tracer MP581 with
operator display
Additional
LonTalk
devices
Use the Rover service tool to create bindings. (Refer to the Rover Operation and Programming
Guide (EMTX-SVX01). Using the Rover service tool, select the network variable from the MP503
nvoVolts4 SNVT_volt Universal Input 4 Status Output:
• Indicates the value of universal input 4 if it is configured
as 0–10 Vdc.
• If universal input 4 is not configured as 0–10 Vdc, this
output is -3276.8.
nvoBOP1Status SNVT_switch Binary Output 1 Status Output:
• Indicates the value of binary output 1.
nvoBOP2Status SNVT_switch Binary Output 3 Status Output:
• Indicates the value of binary output 2.
nvoBOP3Status SNVT_switch Binary Output 3 Status Output:
• Indicates the value of binary output 3.
nvoBOP4Status SNVT_switch Binary Output 4 Status Output:
• Indicates the value of binary output 4.
Table 2. Tracer MP503 network variable outputs (continued)
Variable name Data type Description

CNT-SVX09E-EN 17
Network Variable Bindings
and then select the MP581. The Rover service tool shows only the variables in the MP581 for the
SNVT that matches the variable selected in the MP503 (refer to Table 3.
Table 3. Bindings for example 1
After completing the bindings, program the MP581 to display this data on the operator display.
Important:

Remember that the outside air humidity is being transmitted over the network in
units of mA. Some custom programming is required in the MP581 to convert the
humidity from units of mA to units of percent (%). Custom programming in the
MP581 also uses the outside air temperature and humidity to calculate the outside
air enthalpy and use it to control the economizer of the AHU.
Example 2: Display Sensor Readings from a MP503 on Two Different MP581 Operator
Displays
This example builds on example 1 and shows that bindings can be one-to-many. In this example,
a second MP581 is added to the system as described in example 1. The second MP581 also controls
an AHU. This AHU requires the outside air enthalpy in order to control its economizer. As in
example 1, use bindings to allow the economizer control in the second MP581 to calculate outside
air enthalpy. Figure 7 shows the LonTalk network for this example.
Figure 7. LonTalk network for example 2
®
LonTalk link
Tracer MP503
Tracer MP581 #1
with operator display
Tracer MP581 #2
with operator display
Additional
LonTalk
devices
Use the Rover service tool to create bindings. (Refer to the Rover Operation and Programming
Guide (EMTX-SVX01). Using the Rover service tool, select the network variable from the MP503
and then select the second MP581. The Rover service tool shows only the variables in MP581 #2
Network Variable Output on the
MP503 Binding To Network Variable Input on the MP581
nvoTemperature1 nviTemp01(a)
(a) The MP581 has 40 generic temperature (SNVT_temp_p) network variable inputs available for binding (nviTemp01 through
nviTemp40).
nvoCurrent2 nviCurrent_mA01(b)
(b)The MP581 has 8 generic current (SNVT_amp_mil) network variable inputs available for binding (nviCurrent_mA01 through
nviCurrent_mA08).
nvoBIP3Status nviSwitch01(c)
(c) The MP581 has 40 generic binary (SNVT_switch) network variable inputs available for binding (nviSwitch01 through nviS-
witch40).
nvoBIP4Status nviSwitch01(c)

18 CNT-SVX09E-EN
Network Variable Bindings
of the SNVT that matches the variable selected in the MP503. Table 4 shows the bindings required
between the MP503 and MP581 #2.
Table 4. Bindings for example 2
After completing the bindings, program Tracer MP581 #2 to calculate enthalpy from the outside air
temperature and humidity.\
Important:

Custom programming is required to display this data on the operator display of
Tracer MP581 #2. Remember that the outside air humidity is being transmitted over
the network in units of mA. Some custom programming is required in Tracer MP581
#2 to convert the humidity from units of mA to units of percent (%) before performing
the enthalpy calculation.
Example 3: Control a Binary Output on the MP503 from a MP581
This example shows an nvi on the MP503 being bound, which allows a binary output on the MP503
to be controlled by another device on the LonTalk network. In this example, binary output 1 on the
MP503 is starting and stopping an exhaust fan. The MP503 is communicating via the LonTalk
network to a MP581 that is controlling an AHU. The AHU and the exhaust fan follow the same
schedule; for example, whenever the AHU runs, the exhaust fan runs.
Bind an nvo on the MP581 to an nvi on the MP503 so the AHU and exhaust fan run together. Figure 8
shows the LonTalk network for this example.
Figure 8. LonTalk network for example 3
®
LonTalk link
Tracer MP503
Tracer MP581 with
operator display
Additional
LonTalk
devices
Network Variable Output on the
MP503 Binding To Network Variable Input on the MP581 #2
nvoTemperature1 nviTemp01(a)
(a) The MP581 has 40 generic temperature (SNVT_temp_p) network variable inputs available for binding (nviTemp01 through
nviTemp40).
nvoCurrent2 nviCurrent_mA01(b)
(b)The MP581 has 40 generic temperature (SNVT_temp_p) network variable inputs available for binding (nviTemp01 through
nviTemp40).
1The Tracer MP581 has 40 generic temperature (SNVT_temp_p) network variable inputs available for
binding (nviTemp01 through nviTemp40).
2The Tracer MP581 has 8 generic current (SNVT_amp_mil) network variable inputs available for binding
(nviCurrent_mA01 through nviCurrent_mA08).

CNT-SVX09E-EN 19
Network Variable Bindings
Use the Rover service tool to create bindings (refer to the Rover Operation and Programming Guide
(EMTX-SVX01). Using the Rover service tool, select the network variable from the MP581 and then
select the MP503. The Rover service tool shows only the variables in the MP503 of the SNVT that
matches the variable selected in the MP581. Table 5 shows the required bindings.
Table 5. Bindings for example 3
Custom programming in the MP581 controls nvoSwitch01. Write a custom program to control
nvoSwitch01 ON when the AHU is ON and OFF when the AHU is OFF. The network binding passes
the command to the binary output on the MP503.
Example 4: Use a Sensor Reading on a MP503 to Control a Pump VFD on a MP581
In this example, an MP581 is controlling the variable frequency drive (VFD) of a chilled water pump.
Use a differential pressure sensor (4–20 mA output) to control the speed of this pump.
Unfortunately, the differential pressure sensor is located more than 1000 ft. away from the pump,
therefore, it cannot be wired directly to the universal input on the MP581. Install an MP503 to read
the differential pressure and then use network bindings to send the pressure value to the MP581
controlling the chilled water pump VFD. Figure 9 shows the LonTalk network for this example.
Figure 9. LonTalk network for example 4
Use the Rover service tool to create bindings (refer to the Rover Operation and Programming Guide
(EMTX-SVX01). Using the Rover service tool, select the network variable from the MP503 and then
select the MP581. The Rover service tool shows only the variables in the MP581 of the SNVT that
matches the variable selected in the MP503. Table 6 shows the required bindings.
Table 6. Bindings for example 4
Network Variable Output on the
MP581 Binding To Network Variable Input on the MP503
nvoSwitch01(a)
(a) The MP581 has 40 generic binary (SNVT_switch) network variable outputs available for binding (nvoSwitch01 through
nvoSwitch40).
nviBOP1Request
Network Variable Output on the
MP503 Binding To Network Variable Input on the MP581
nvoCurrent1 nviCurrent_mA01(a)
(a) The MP581 has 8 generic current (SNVT_amp_mil) network variable inputs available for binding (nviCurrent_mA01 through
nviCurrent_mA08).
®
LonTalk link
Tracer MP503
Tracer MP581 with
operator display
Additional
LonTalk
devices

20 CNT-SVX09E-EN
Status Indicators
Status Indicators
This section provides information about the following:
• MP503 circuit board
• Service pin button
• Interpreting LEDs
• Diagnostics
MP503 Circuit Board
Figure 10 shows the location of the Service Pin button, the Neuron ID label, and LEDs.
Figure 10. Tracer MP503 I/O module circuit board
Service Pin Button
The Service Pin button is located as shown inFigure 10 above, and is used to:
• Identify a device
• Add a device to the active group
• Verify PCMCIA communications
• Make the Status (green) LED wink to verify that the module is communicating on the link
Refer to the Rover Operation and Programming Guide (EMTX-SVX01).
LonTalk LED (yellow)
Neuron ID label
(on back of terminal block)
Service Pin button
Status LED (green)
Service LED (red)
Neuron chip
Binary output 1 LED (green) Binary output 2 LED (green) Binary output 3 LED (green) Binary output 4 LED (green)