Johnson Controls IOM2723, IOM2721 Installation Manual

IOM2723 Input/Output Module Installation

Application

The MS-IOM2723 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.

Note: The IOM2723 model is only available
in certain regions. Contact your local Johnson
Controls representative for more information.

IOMs operate on an RS-485 BACnet® MS/TP Bus
and integrate into Johnson Controls® and third­party 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.

Guide

Part No. 24-10143-1108 Rev. E

2019-10-18

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)

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

• 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

*24101431108E*

(barcode for factory use only)

MS-IOM2723

description of the physical features and a reference
to further information where required.

Figure 1: IOM2723 Physical Features

Table 1: IOM2723 physical features callouts and
descriptions

Physical feature: description and references

1 Analog Outputs (AOs) Terminal Block (see Table 2)
2 Mounting Clip

3

4

5

6

7

8 Universal Inputs (UIs) Terminal Block (see Table 2)
9 LED Status Indicators (see Table 8)

Device Address DIP Switch Block (see Setting the device

address)

24 VAC, Class 2 Supply Power Terminal Block (see Supply

power terminal block)

Cover Lift Tab (see Removing the expansion module

cover)

Sensor Actuator (SA) Bus/Field Controller (FC) Bus
Terminal Block (see SA/FC bus terminal block)

End-of-Line (EOL) Termination Switch (see Setting the

End-of-Line (EOL) Switch)

Mounting

Observe the following guidelines when mounting an
expansion module:

• Ensure the mounting surface can support the
expansion module, DIN rail, and any user­supplied 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 10.

• 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.

IOM2723 Input/Output Module Installation Guide2

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

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.

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

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

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).

IOM2723 Input/Output Module Installation Guide 3

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.

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

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.

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.

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.

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 Figure 1 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. See Table 2 for
more information about I/O terminal functions,
requirements, and ratings.

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

IOM2723 Input/Output Module Installation Guide4

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.

Supply power terminal block

The 24 VAC supply power terminal block is a gray,
removable, 3-terminal plug that fits into a board­mounted 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 6. The middle
terminal on the supply power terminal block is not
used.

Figure 6: 24 VAC supply power terminal block
wiring

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.

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.

IOM2723 Input/Output Module Installation Guide 5

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.

IOM2723 Input/Output Module Installation Guide6