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