Johnson Controls IOM2721 User manual

IOM2721 Input/Output Module Installation Guide
Application
The IOM2721 input/output expansion module is part of
the Metasys® system Field Equipment Controller family.
Input/Output expansion modules (IOMs) expand the
number of Input/Output points connected to either a
Network Automation Engine (NAE), Network Control
Engine (NCE), Advanced Application Field Equipment
Controller (FAC), Field Equipment Controller (FEC), or
Variable Air Volume Modular Assembly (VMA) to monitor
and control a wide variety of HVAC equipment.
IOMs operate on an RS-485 BACnet® MS/TP Bus and
integrate into Johnson Controls® and third-party BACnet
systems. IOMs communicate using the BACnet MS/TP
protocol when directly connected to the FC Bus.
Note: With Release 10.1 or later of the Controller
Configuration Tool (CCT), VMAs, FECs, and FACs
can be configured to communicate using either
the BACnet MS/TP or the N2 field bus networking
protocol. The operation of the IOM is not affected by
the selection of the BACnet MS/TP or the N2 protocol
in the host controller, when the IOM is connected to
the host controller using the SA bus.
North American emissions compliance
United States
This equipment has been tested and found to comply with
the limits for a Class A digital device pursuant to Part 15
of the FCC Rules. These limits are designed to provide
reasonable protection against harmful interference when
this equipment is operated in a commercial environment.
This equipment generates, uses, and can radiate radio
frequency energy and, if not installed and used in
accordance with the instruction manual, may cause
harmful interference to radio communications. Operation
of this equipment in a residential area may cause harmful
interference, in which case the users will be required to
correct the interference at their own expense.
Canada
This Class (A) digital apparatus meets all the requirements
of the Canadian Interference-Causing Equipment
Regulations.
Cet appareil numérique de la Classe (A) respecte toutes
les exigences du Règlement sur le matériel brouilleur du
Canada.
Installation
Observe these guidelines when installing an expansion
module:
• To minimize vibration and shock damage, transport the
expansion module in the original container.
• Verify that all parts shipped with the expansion module.
• Do not drop the expansion module or subject it to
physical shock.
Parts included
• One MS-IOM expansion module with removable
terminal blocks (Power and SA/FC bus are removable)
• One installation instructions sheet
Materials and special tools needed
• Three fasteners appropriate for the mounting surface
(M4 screws or #8 screws)
• One 20 cm (8 in.) or longer piece of 35 mm DIN rail and
appropriate hardware for DIN rail mount
• Small straight-blade screwdriver for securing wires in
the terminal blocks
Physical features
The following figure displays the physical features of the
IOM, and the accompanying table provides a description
of the physical features and a reference to further
information where required.
*2410144149L*
Part No. 24-10144-149 Rev. L
2019-10-18
MS-IOM2721
(barcode for factory use
only)

Figure 1: IOM2721 physical features
Table 1: IOM2721 physical features callouts and
descriptions
Physical feature: description and references
1 Analog Outputs (AOs) Terminal Block (see Table 2)
2 Mounting Clip
3 Device Address DIP Switch Block (see )
424 VAC, Class 2 Supply Power Terminal Block (see Supply
power terminal block)
5Cover Lift Tab (see Removing the expansion module
cover)
6Sensor Actuator (SA) Bus/Field Controller (FC) Bus
Terminal Block (see SA/FC bus terminal block)
7End-of-Line (EOL) Termination Switch (see Setting the
End-of-Line (EOL) Switch)
8 Universal Inputs (UIs) Terminal Block (see Table 2)
9 LED Status Indicators (see Table 8)
Mounting
Observe the following guidelines when mounting an
expansion module:
• Ensure the mounting surface can support the
expansion module, DIN rail, and any user-supplied
enclosure.
• Mount the expansion module horizontally on 35 mm
DIN rail whenever possible.
• Mount the expansion module in the proper mounting
position (Figure 2).
• Mount the expansion module on a hard, even surface
whenever possible in wall-mount applications.
• Use shims or washers to mount the expansion module
securely and evenly on the mounting surface.
• Mount the expansion module in an area free of
corrosive vapors and observe the Ambient Conditions
requirements in Table 9.
• Provide for sufficient space around the expansion
module for cable and wire connections for easy cover
removal and good ventilation through the expansion
module (50 mm [2 in.] minimum on the top, bottom,
and front of the expansion module).
• Do not mount the expansion module on surfaces prone
to vibration, such as duct work.
• Do not mount the expansion module in areas where
electromagnetic emissions from other devices or wiring
can interfere with expansion module communication.
Observe these additional guidelines when mounting an
expansion module in a panel or enclosure:
• Mount the expansion module so that the enclosure
walls do not obstruct cover removal or ventilation
through the expansion module.
• Mount the expansion module so that the power
transformer and other devices do not radiate excessive
heat to the expansion module.
• Do not install the expansion module in an airtight
enclosure.
Figure 2: Mounting positions
DIN rail mount applications
About this task:
IOM2721 Input/Output Module Installation Guide2

Mounting the expansion module horizontally on 35 mm
DIN rail is the preferred method.
To mount an expansion module on a 35 mm DIN rail,
complete the following steps:
1. Securely mount a 20 cm (8 in.) or longer
section of 35 mm DIN rail, horizontally and
centered in the desired space, so that the
expansion module mounts in the position
shown in Figure 2.
2. Pull the two bottom mounting clips outward
from the expansion module to the extended
position (Figure 3).
3. Hang the expansion module on the DIN rail
by the hooks at the top of the DIN rail channel
on the back of the expansion module (Figure
3), and position the expansion module snugly
against the DIN rail.
4. Push the bottom mounting clips inward (up)
to secure the expansion module on the DIN
rail.
To remove the expansion module from the DIN rail,
pull the bottom mounting clips out to the extended
position and carefully lift the expansion module off
the DIN rail.
Wall mount applications
About this task:
To mount an expansion module directly on a wall or other
flat vertical surface, complete the following steps:
1. Pull the two bottom mounting clips outward
and ensure they are locked in the extended
position, as shown in Figure 3.
2. Mark the mounting hole locations on the wall
using the dimensions in Figure 3 and one of
the mount positions shown in Figure 2. You
can also hold the expansion module up to the
wall or surface in a proper mount position and
mark the hole locations through the mounting
clips.
3. Drill holes in the wall or surface at the marked
locations, and insert appropriate wall anchors
in the holes (if necessary).
4. Hold the expansion module in place, and
insert the screws through the mounting clips
and into the holes (or anchors). Carefully
tighten all of the screws.
Important: Do not overtighten the mounting
screws. Overtightening the screws may damage
the mounting clips.
Mounting features and dimensions
See the following figure for mounting dimensions listed
in millimeters and inches. Inches are listed in parenthesis.
The following figure also illustrates the DIN rail channel
and the mounting clips in an extended position.
Figure 3: Back of expansion module
Wiring
WARNING
Risk of Electric Shock:
Disconnect or isolate all power supplies before
making electrical connections. More than one
disconnection or isolation may be required to
completely de-energize equipment. Contact with
components carrying hazardous voltage can cause
electric shock and may result in severe personal injury
or death.
AVERTISSEMENT
Risque de décharge électrique:
Débrancher ou isoler toute alimentation avant
de réaliser un branchement électrique. Plusieurs
isolations et débranchements sont peut-être
nécessaires pour -couper entièrement l'alimentation
de l'équipement. Tout contact avec des composants
conducteurs de tensions dangereuses risque
d'entraîner une décharge électrique et de provoquer
des blessures graves, voire mortelles.
IOM2721 Input/Output Module Installation Guide 3

CAUTION
Risk of Property Damage:
Do not apply power to the system before checking
all wiring connections. Short circuited or improperly
connected wires may result in permanent damage to
the equipment.
ATTENTION
Mise En Garde: Risque de dégâts matériels:
Ne pas mettre le système sous tension avant
d'avoir vérifié tous les raccords de câblage. Des
fils formant un court-circuit ou connectés de façon
incorrecte risquent d'endommager irrémédiablement
l'équipement.
Important: Do not exceed the expansion module
electrical ratings. Exceeding expansion module
electrical ratings can result in permanent damage to
the expansion modules and void any warranty.
Important: Use copper conductors only. Make
all wiring in accordance with local, national, and
regional regulations.
Important: Electrostatic discharge can damage
expansion module components. Use proper
electrostatic discharge precautions during
installation, setup, and servicing to avoid damaging
the expansion module.
For detailed information on configuring and wiring
an MS/TP bus, FC bus, and SA bus, refer to the MS/TP
Communications Bus Technical Bulletin (LIT-12011034).
Terminal blocks and bus ports
See Physical features for terminal block and bus port
locations on the expansion module. Observe the following
guidelines when wiring an expansion module.
Input and output terminal blocks
The input terminal blocks are mounted on the bottom of
the expansion module and the output terminal blocks are
mounted on the top of the expansion module.
SA/FC bus terminal block
An IOM can be connected to a Sensor/Actuator (SA)
bus or a Field Controller (FC) bus, but not to both buses
simultaneously. The SA/FC bus terminal block is a
removable, 4-terminal plug that fits into a board-mounted
jack.
When connecting the IOM to an FC bus, wire the bus
terminal block plugs on the expansion module, and the
other controllers and expansion modules in a daisy-chain
configuration using 3-wire twisted, shielded cable as
shown in Figure 4.
Figure 4: FC bus terminal block wiring
When connecting the IOM to an SA bus, wire the bus
terminal block plugs on the expansion module and other
SA bus devices in a daisy-chain configuration using 4-wire
twisted, shielded cable as shown in Figure 5.
Figure 5: SA bus terminal block wiring
Note: The SA PWR/SHLD terminal does not supply 15
VDC. The SA PWR/SHLD terminal is isolated and can
be used to connect (daisy chain) the 15 VDC power
leads on the SA bus (Figure 5) or the cable shields on
the FC bus (Figure 4). The SA bus supervisor supplies
15 VDC to devices on the SA bus requiring power.
SA/FC bus port
The SA/FC bus port on the front of the expansion
module is an RJ-12, 6-position modular jack that provides
a connection for devices on the SA bus, a Wireless
Commissioning Converter, or ZFR/ZFR Pro Wireless
Router (depending on which wireless system the IOM is
operating on).
The SA/FC bus port is connected internally to the SA/FC
bus terminal block. See Table 4 for more information. The
SA/FC bus Port pin assignment is shown in Figure 6.
IOM2721 Input/Output Module Installation Guide4

Figure 6: Pin number assignments for sensor, SA bus
and FC bus ports on expansion modules
Supply power terminal block
The 24 VAC supply power terminal block is a gray,
removable, 3-terminal plug that fits into a board-mounted
jack on the top right of the expansion module.
Wire the 24 VAC supply power wires from the transformer
to the HOT and COM terminals on the terminal plug as
shown in Figure 7. The middle terminal on the supply
power terminal block is not used.
Figure 7: 24 VAC supply power terminal block wiring
Note: The supply power wire colors may be different
on transformers from other manufacturers. Refer to
the transformer manufacturer’s instructions and the
project installation drawings for wiring details.
Important: Connect 24 VAC supply power to the
expansion module and all other network devices
so that transformer phasing is uniform across the
network devices. Powering network devices with
uniform 24 VAC supply power phasing reduces
noise, interference, and ground loop problems. The
expansion module does not require an earth ground
connection.
Wireless network applications
About this task:
The expansion module can also be installed in a wireless
application using a ZFR/ZFR Pro Wireless Field Bus Router.
To configure an expansion module for use with the ZFR/
ZFR Pro Series Wireless Field Bus system:
Note: IOMs can communicate wirelessly on the FC
bus only.
1. Connect the ZFR181x or ZFR182x Wireless
Field Bus Router to the FC bus port (RJ-12
modular jack) on the front of the expansion
module.
2. Ensure that the expansion module's device
address DIP switches are set to the correct
device address. See .
3. Set DIP switch 128 to ON, which enables
wireless operation on the expansion module.
Result:
For more information on the ZFR Pro Wireless Field Bus
system, refer to the WNC1800/ZFR182x Pro Series Wireless
Field Bus System Product Bulletin (LIT-12012320).
For more information on the ZFR 1800 Wireless Field
Bus system, refer to the ZFR1800 Series Wireless Field Bus
System Product Bulletin (LIT-12011336).
Terminal Wiring Guidelines,
Functions, Ratings, and
Requirements
Input and output wiring guidelines
Table 2 provides information and guidelines about the
functions, ratings, and requirements for the expansion
module input and output terminals, and references
guidelines for determining proper wire sizes and cable
lengths.
In addition to the wiring guidelines in Table 2, observe
the following guidelines when wiring expansion module
inputs and outputs:
• Run all low-voltage wiring and cables separate from
high-voltage wiring.
• All input and output cables, regardless of wire size or
number of wires, should consist of stranded, insulated,
and twisted copper wires.
• Shielded cable is not required for input or output
cables.
• Shielded cable is recommended for input and output
cables that are exposed to high electromagnetic or
radio frequency noise.
• Inputs/outputs with cables less than 30 m (100 ft)
typically do not require an offset in the software setup.
Cable-runs over 30 m (100 ft) may require an offset in
the input/output software setup.
IOM2721 Input/Output Module Installation Guide 5

I/O Terminal blocks, ratings, and
requirements
Table 2: I/O terminal blocks, functions, ratings, requirements, and cables
Terminal block label Terminal
label Function, ratings, requirements Determine wire size and maximum cable length
+15 V
15 VDC Power Source for active (3-wire) input devices
connected to the Universal INn terminals.
Provides 100 mA total current
Same as (Universal) INn
Note: Use 3-wire cable for
devices that source power
from the +15 V terminal.
Analog Input - Voltage Mode (0–10 VDC)
10 VDC maximum input voltage
Internal 75k ohm Pull-down
See Guideline A in Table 3.
Analog Input - Current Mode (4–20 mA)
Internal 100 ohm load impedance
Note: A current loop fail-safe jumper can be positioned
to maintain a closed 4 to 20 mA current loop, even when
the power to the expansion module is interrupted or off.
See Guideline B in Table 3.
Analog Input - Resistive Mode (0–600k ohm)
Internal 12 V. 15k ohm pull up
Qualified Sensors: 0-2k ohm potentiometer, RTD (1k Nickel
[ Johnson Controls sensor], 1k Platinum, and A99B Silicon
Temperature Sensor) Negative Temperature Coefficient (NTC)
Sensor (10k Type L, 10k JCI Type II, 2.252k Type II)
See Guideline A in Table 3.
INn
Binary Input - Dry Contact Maintained Mode
1 second minimum pulse width
Internal 12 V. 15k ohm pull up
See Guideline A in Table 3.
UNIVERSAL
(Inputs)
ICOMnUniversal Input Common for all Universal Input terminals Same as (Universal) INn
Analog Output - Voltage Mode (0–10 VDC)
10 VDC maximum output voltage
10 mA maximum output current
Required an external load of 1,000 ohm or more.
Note: The Analog Output (AO) operates in the Voltage
Mode when connected to devices with impedances
greater than 1,000 ohm. Devices that drop below 1,000
ohm may not operate as intended for Voltage Mode
applications.
OUTn
Analog Output - Current Mode (4–20 mA)
Requires an external load between 0 and 300 ohm.
Note: The Analog Output (AO) operates in the Current
Mode when connected to devices with impedances less
than 300 ohm. Devices that exceed 300 ohm may not
operate as intended for Current Mode applications.
ANALOG
(Outputs)
OCOMnAnalog Output Signal Common for all Analog OUT terminals.
See Guideline C in Table 3.
IOM2721 Input/Output Module Installation Guide6

Cable and wire length guidelines
The following table defines cable length guidelines for the various wire sizes that may be used for wiring low-voltage
(<30 V) input and outputs.
Table 3: Cable length guidelines
Guideline Wire size/gauge and type Maximum cable length
and type Assumptions
1.0 mm (18 AWG) stranded copper 457 m (1,500 ft) twisted wire
0.8 mm (20 AWG) stranded copper 297 m (975 ft) twisted wire
0.6 mm (22 AWG) stranded copper 183 m (600 ft) twisted wire
A
0.5 mm (24 AWG) stranded copper 107 m (350 ft) twisted wire
100 mV maximum voltage drop
Depending on cable and the connected input or
output device, you may have to define an offset
in the setup software for the input or output
point.
1.0 mm (18 AWG) stranded copper 229 m (750 ft) twisted wire
0.8 mm (20 AWG) stranded copper 137 m (450 ft) twisted wire
0.6 mm (22 AWG) stranded copper 91 m (300 ft) twisted wire
B
0.5 mm (24 AWG) stranded copper 61 m (200 ft) twisted wire
100 mV maximum voltage drop
Depending on cable and the connected input or
output device, you may have to define an offset
in the setup software for the input or output
point.
CSee Figure 8 to select wire size/gauge.
Use stranded copper wire.
See Figure 8 to determine
cable length. Use twisted
wire cable.
N/A
Maximum cable length versus load current
Use the following figure to estimate the maximum cable
length relative to the wire size and the load current (in
mA) when wiring inputs and outputs.
Note: The following information applies to low-
voltage (<30 V) inputs and outputs only.
Figure 8: Maximum wire length for low-voltage (<30 V)
Inputs and Outputs by current and wire size
Communications bus and supply power
wiring guidelines
Table 4 provides information about the functions, ratings,
and requirements for the communication bus and supply
power terminals; it additionally provides guidelines for
wire sizes, cable types, and cable lengths when wiring the
expansion module's communication buses and supply
power.
In addition to the guidelines in Table 4, observe these
guidelines when wiring an SA or FC bus and the 24 VAC
supply power:
• Run all low-voltage wiring and cables separate from
high-voltage wiring.
• All SA and FC bus cables, regardless of wire size, should
be twisted, insulated, stranded copper wire.
• Shielded cable is strongly recommended for all SA and
FC bus cables.
• Refer to the MS/TP Communications Bus Technical
Bulletin (LIT-12011034) for detailed information
regarding wire size and cable length requirements for
the SA and FC buses.
IOM2721 Input/Output Module Installation Guide 7

Communications bus and supply power terminal blocks, ratings, and requirements
Table 4: Communications bus and supply power terminal blocks, functions, ratings, requirements, and cables
Terminal block/Port
label Terminal labels Function, electrical ratings/Requirements required cable type
+
-FC or SA Bus Communications
COM Signal Reference (Common) for FC or SA Bus
communications
FC BUS
or
SA BUS SHLD
or
SA PWR
SHLD on FC Bus: Isolated terminal (optional
shield drain connection)
SA PWR on SA Bus: 15 VDC power lead
connection.
Note: The SA PWR terminal on an IOM
expansion module does not supply 15
VDC. The SA bus supervisor supplies 15
VDC to devices on the SA bus requiring
power.
FC Bus: 0.6 mm (22 AWG) stranded, 3-wire
twisted, shielded cable required.
SA Bus: 0.6 mm (22 AWG) stranded, 4-wire
(2 twisted-pairs), shielded cable required.
Note: On the SA Bus, the + and - wire
are one twisted pair, and the COM
and SA PWR are the second twisted
pair of wires.
HOT 24 VAC Power Supply - Hot
Supplies 20–30 VAC (Nominal 24 VAC)
24~
COM 24 VAC Power Supply - Common
0.8 mm to 1.0 mm
(18 AWG) 2-wire
Note: See to determine wire size and cable lengths
for cables.
Note: The SA Bus and FC Bus wiring
recommendations in this table are for MS/TP bus
at 38,400 baud. For more information, refer to
the MS/TP Communications Bus Technical Bulletin
(LIT-12011034).
IOM2721 Input/Output Module Installation Guide8

Termination details
A set of Johnson Controls termination diagrams provides
details for wiring inputs and outputs to the controllers.
See the figures in this section for the applicable
termination diagrams.
Table 5: Termination details
Type of field device Type of Input/
Output Termination diagrams
Temperature Sensor UI
Voltage Input - External
Source UI
Voltage Input - Internal
Source UI
Voltage Input (Self-
Powered) UI
Current Input - External
Source (Isolated) UI
Current Input - Internal
Source (2-wire) UI
IOM2721 Input/Output Module Installation Guide 9

Table 5: Termination details
Type of field device Type of Input/
Output Termination diagrams
Current Input - Internal
Source (3-wire) UI
Current Input - External
Source (in Loop) UI
Feedback from
EPP-1000 UI
Dry Contact (Binary
Input) UI
0–10 VDC Output to
Actuator (External
Source)
AO
0–10 VDC Output to
Actuator (Internal
Source)
AO
IOM2721 Input/Output Module Installation Guide10

Table 5: Termination details
Type of field device Type of Input/
Output Termination diagrams
Analog Output
(Current) AO
4–20 mA Output to
Actuator AO
Voltage (Analog Output) AO
4–20 mA Output to
Actuator AO
Setup and Adjustments
Setting the device address
About this task:
Metasys expansion modules are master devices on MS/
TP (SA or FC) buses. Before operating an expansion
module on a bus, you must set a valid and unique device
address for each expansion module on the bus. You set
an expansion module's device address by setting the
positions of the switches on the DIP switch block at the
top of the expansion module . Device addresses 4 through
127 are the valid addresses for these expansion modules.
The DIP switch block has eight switches numbered 128,
64, 32, 16, 8, 4, 2, and 1. Switches 64 through 1 are device
address switches. Switch 128 must be set to off for all
hard-wired SA and FC bus applications. Switch 128 must
be set to OFF for all hard-wired SA and FC Bus applications
Figure 9: Device address DIP switch block set to
address 21
IOM2721 Input/Output Module Installation Guide 11

Note: Metasys controllers ship with switch 128 ON
and the remaining address switches OFF rendering
the controllers wired subordinate devices, which do
not operate on MS/TP buses, but do not interfere
with bus operation. Set a valid and unique device
address on the expansion module before applying
power to the expansion module on the bus.
To set the device addresses on Metasys expansion
modules, complete the following steps:
1. Set all of the switches on the address DIP
switch block (128 through 1) to OFF.
2. Set one or more of the seven address switches
(64 though 1) to ON, so that the sum of the
switch numbers set to ON equals the intended
device address, and ensure that switch 128
remains set to OFF.
Note: To do this, set the highest number switch
that is less than or equal to the intended device
address to ON. Then continue setting lower
numbered switches until the total equals the
intended address. For example, if the intended
device address is 21, set switches 16, 4, and 1 to
ON (16+4+1= 21) and all other switches to OFF.
3. Set a unique and sequential device address
for each of the expansion modules connected
on the SA or FC bus starting with device
address 4.
Note: To ensure the best bus performance,
set sequential device addresses with no gaps
in the device address range (4, 5, 6, 7, 8, 9, and
so on). The expansion modules do not need
to be physically connected on the bus in their
numerical device address order.
4. Write each expansion module's device
address on the white label below the DIP
switch block on the expansion module's
cover.
The following table describes the FC bus and SA
bus device addresses for Johnson Controls MS/
TP communications bus applications.
Table 6: SA/FC bus device address descriptions
Device Address Use on Descriptions
0
(Switch 128 Off)
Reserved for FC Bus Supervisory Controller (not
for use on controllers or expansion modules).
1-3
(Switch 128 Off)
Reserved for peripheral devices (not for use on
controllers or expansion modules).
4-127
(Switch 128 Off)
Used for MSTP master devices (controllers and
expansion modules) that are hardwired to an
SA bus or FC bus.
Removing the expansion module cover
About this task:
Important: Electrostatic discharge can damage
expansion module components. Use proper
electrostatic discharge precautions during
installation, setup, and servicing to avoid damaging
the expansion module.
Important: Disconnect all power sources to
the expansion module before removing cover
and changing the position of any jumper or the
EOL switch on the expansion module. Failure to
disconnect power before changing a jumper or
EOL switch position can result in damage to the
expansion module and void any warranties.
The expansion module cover is held in place by four
plastic latches that extend from the base and snap
into slots on the inside of the housing cover.
To remove the expansion module cover, complete
the following steps:
1. Place your fingernails under the two cover lift
tabs on the sides of the housing cover and
gently pry the top of the cover away from the
base to release the cover from the two upper
latches.
2. Pivot the top of the cover further to release it
from the lower two latches.
3. Replace the cover by placing it squarely over
the base, and then gently and evenly push the
cover on to the latches until they snap into the
latched position.
Figure 10: Controller with cover removed
Setting the End-of-Line (EOL) switch
About this task:
Each expansion module has an EOL switch. When the
EOL switch is set to ON, it sets the expansion module as a
terminating device on the bus. See Figure 11 for the EOL
switch location. The default EOL switch position is OFF.
IOM2721 Input/Output Module Installation Guide12

Figure 11: End-of-Line switch positions
To set the EOL switch on an expansion module, complete
the following steps:
1. Determine the physical location of the
expansion module on the SA or FC bus.
2. Determine if the expansion module must be
set as a terminating device on the bus.
Note: The EOL termination rules for SA
buses and FC buses are different. Refer to
the MS/TP Communications Bus Technical
Bulletin (LIT-12011034) for detailed information
regarding EOL termination rules and EOL
switch settings on SA and FC buses.
3. If the expansion module is a terminating
device on the FC bus, set the EOL switch
to ON. If the expansion module is not a
terminating device on the bus, set the EOL
switch to OFF.
When an expansion module is connected to
power with its EOL switch set to ON, the amber
EOL LED on the expansion module cover is lit.
UI current loop jumpers
The UI current loop fail-safe jumpers are on the circuit
board under the expansion module cover near the UI
terminals. When a UI is defined (in the system software)
as a 4 to 20 mA Analog Input and the UI’s current loop
jumper is in the Disabled (default) position (Figure 12), the
4 to 20 mA current loop circuit opens whenever power to
the expansion module is interrupted or off.
Figure 12: Current loop jumper positions
Setting the current loop jumper to the Enabled position
(Figure 12) connects an internal 100 ohm resistor across
the UI terminals, which maintains the 4 to 20 mA current
loop circuit even when power to the expansion module is
interrupted or off.
Important: Current Loop jumpers must be in the
Disabled (default) position for all UIs that are not set
up to operate as 4 to 20 mA analog inputs.
Table 7: UI Inputs and Jumper Labels
Universal Input Label Jumper Label on Circuit Board
Label
IN1 J20
IN2 J21
IN3 J22
IN4 J24
IN5 J25
IN6 J26
IN7 J27
IN8 J28
Commissioning
You commission expansion modules with Controller
Configuration Tool (CCT) software, using a Bluetooth
Wireless Commissioning Converter (BTCVT), through
Mobile Access Portal (MAP) Gateway at version 4.2 or
above, or in BACnet router mode when connected to a
Supervisory Controller. Refer to the Controller Tool Help
(LIT-12011147) for detailed information on commissioning
expansion modules.
Note: The MAP Gateway serves as a replacement for
the BTCVT, which is no longer available for purchase,
but continues to be supported.
Troubleshooting
Observe the Status LEDs on the front of the expansion
module. Table 8 provides LED status indicator information
for troubleshooting the expansion module.
IOM2721 Input/Output Module Installation Guide 13

Table 8: Status LEDs and description of LED states
LED label LED color Normal LED state Description of LED states
POWER Green On Steady
Off Steady = No Supply Power or the expansion module’s polyswitch/resettable
fuse is open. Check Output wiring for short circuits and cycle power to expansion
module.
On Steady = Power Connected
FAULT Red Off Steady
Off Steady = No Faults
On Steady = Device Fault
Blink - 2 Hz = Download or Startup in progress, not ready for normal operation
SA/FC BUS Green Blink - 2 Hz
Blink - 2 Hz = Data Transmission (normal communication)
Off Steady = No Data Transmission (N/A - auto baud not supported)
On Steady = Communication lost, waiting to join communication ring
EOL Amber Off (Except on
terminating devices)
On Steady = EOL switch in ON position
Off Steady = EOL switch in OFF position
Repair information
If an expansion module fails to operate within its
specifications, replace the expansion module. For a
replacement expansion module, contact your Johnson
Controls representative.
IOM2721 Input/Output Module Installation Guide14

Accessories
See the following table for expansion module accessories ordering information.
Table 9: Accessories ordering information
Product code number Description
TP-2420 Transformer, 120 VAC Primary to 24 VAC secondary, 20 VA, Wall Plug
Y65T31-0
Transformer, 120/208/240 VAC Primary to 24 VAC Secondary, 40 VA, Foot Mount, 8 in.
Primary Leads and Secondary Screw Terminals, Class 2
Note: Additional Y6x-x Series transformers are also available. Refer to the Series Y63,
Y64, Y65, Y66, and Y69 Transformers Product Bulletin (LIT-125755) for more information.
AS-XFR050-0 Power transformer (Class 2, 24 VAC, 50 VA maximum output), no enclosure
MS-TBK4BUS-0
Replacement SA/FC Bus Terminal Blocks, 4-Position, Gray, Bulk Pack of 10
Note: This is the standard terminal block that is provided with the expansion module.
AP-TBK4SA-0
Replacement SA Bus Terminal Blocks, 4-Position, Brown, Bulk Pack of 10
Note: These terminal blocks can be used as replacement parts if keeping consistent
terminal block colors is important.
AP-TBK4FC-0
Replacement FC Bus Terminal Blocks, 4-Position, Blue, Bulk Pack of 10
Note: These terminal blocks can be used as replacement parts if keeping consistent
terminal block colors is important.
AP-TBK3PW-0 Replacement Power Terminal Blocks, 3-Position, Gray, Bulk Pack of 10
WNC1800/ZFR182x Pro Wireless field
Bus System
This system is used for installations that support BACnet/IP but can also coexist with the
ZFR1800 Series when installed under the same supervisor (i.e., network engine). Refer to the
WNC1800/ZFR182x Pro Series Wireless Field Bus System Product Bulletin (LIT-12012320) for a list
of available products.
ZFR1800 Series Wireless Field Bus
System
This system is used for installations that only support BACnet MS/TP. Refer to the ZFR1800
Series Wireless Field Bus System Product Bulletin (LIT-12011336) for a list of available products.
NS Series Network Sensors Refer to the NS Series Network Sensors Product Bulletin (LIT-12011574) for specific sensor
model descriptions.
WRZ Series Wireless Room Sensors Refer to the WRZ Series Wireless Room Sensors Product Bulletin (LIT-12000653) for specific
sensor model descriptions.
Mobile Access Portal (MAP) Gateway Refer to the Mobile Access Portal Gateway Catalog Page (LIT-1900869) to identify the
appropriate product for your region.
IOM2721 Input/Output Module Installation Guide 15

Technical specifications
Table 10: IOM2721 technical specifications
Product Code Number MS-IOM2721-0 Input/Output Module
Power Requirement 24 VAC (nominal, 20 VAC minimum/30 VAC maximum), 50/60 Hz, power supply Class 2
(North America), Safety Extra-Low Voltage (SELV) (Europe)
Power Consumption 14 VA maximum MS-IOM2721
Ambient Conditions Operating: 0°C to 50°C (32°F to 122°F); 10% to 90% RH noncondensing
Storage: -40°C to 80°C (-40°F to 176°F); 5% to 95% RH noncondensing
Addressing DIP switch set; valid expansion module device addresses 4–127 (Device addresses 0–3 and
128–255 are reserved and not valid expansion module addresses)
Communications Bus
BACnet MS/TP, RS-485:
3-wire FC Bus between the supervisory controller and other controllers or expansion
modules (for MS/TP bus communications at 38,400 baud)
4-wire SA Bus between expansion module, network sensors and other sensor/actuator
devices, includes a lead to source 15 VDC supply power (from controller or expansion
modules) to bus devices (for MS/TP bus communications at 38,400 baud)
Processor H8SX/166xR Renesas® 32-bit microcontroller
Memory 640 KB Flash Memory and 128 KB Random Access Memory (RAM)
Input and Output Capabilities 8 - Universal Inputs: Defined as 0–10 VDC, 4–20 mA, 0–600k ohm, or Binary Dry Contact
2 - Analog Outputs: Defined as 0–10 VDC or 4–20 mA
Analog Output Resolution and Accuracy Output: 16-bit resolution, +/-200 mV accuracy in 0-10 VDC applications
Terminations Input/Output: Fixed Screw Terminal Blocks
SA/FC Bus and Supply Power: 4-Wire and 3-Wire Pluggable Screw Terminal Blocks
Mounting Horizontal on single 35 mm DIN rail mount (preferred), or screw mount on flat surface
with three integral mounting clips on expansion module
Housing Enclosure material: ABS and polycarbonate UL94 5VB; self-extinguishing, plenum-rated
Protection Class: IP20 (IEC529)
Dimensions (Height x Width x Depth)
150 mm x 164 mm x 53 mm (5-7/8 in. x 6-1/2 in. x 2-1/8 in.) including terminals and
mounting clips
Note: Mounting space requires an additional 50 mm (2 in.) on top, bottom, and
front face of expansion module for easy cover removal, ventilation, and wire
terminations.
Weight 0.5 kg (1.1 lb)
Compliance
United States: UL Listed, File E107041, CCN PAZX, UL 916, Energy Management
Equipment
FCC Compliant to CFR47, Part 15, Subpart B, Class A
Canada: UL Listed, File E107041, CCN PAZX7 CAN/CSA C22.2 No.205, Signal Equipment
Industry Canada Compliant, ICES-003
Europe: Johnson Controls declares that this product is in compliance with the essential
requirements and other relevant provisions of the EMC Directive.
Australia and New Zealand: RCM Mark, Australia/NZ Emissions Compliant
BACnet International Compliance BACnet International: BACnet Testing Laboratories (BTL) Protocol Revision 4 Listed
BACnet Application Specific Controller (B-ASC).
The performance specifications are nominal and conform to acceptable industry standard. For application at conditions beyond
these specifications, consult the local Johnson Controls® office. Johnson Controls shall not be liable for damages resulting from
misapplication or misuse of its products.
Product warranty
This product is covered by a limited warranty, details
of which can be found at www.johnsoncontrols.com/
buildingswarranty.
IOM2721 Input/Output Module Installation Guide16

Single point of contact
APAC Europe NA/SA
JOHNSON CONTROLS
C/O CONTROLS PRODUCT
MANAGEMENT
NO. 32 CHANGJIJANG RD NEW
DISTRICT
WUXI JIANGSU PROVINCE 214028
CHINA
JOHNSON CONTROLS
WESTENDHOF 3
45143 ESSEN
GERMANY
JOHNSON CONTROLS
507 E MICHIGAN ST
MILWAUKEE WI 53202
USA
IOM2721 Input/Output Module Installation Guide 17

© 2019 Johnson Controls. All rights reserved. All specifications and other information shown were current as of document revision and
are subject to change without notice.
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