Johnson Controls FX-PCX2721, FX-PCX3721 Installation Instructions Manual

FX-PCX2721 Expansion Input/Output Module Installation
Instructions

FX-PCX2721-0

Part No. 24-10144-173, Rev. F

Issued August 2018

Application

The FX-PCX2721 controller is part of the Facility Explorer
FX-PC Series Programmable Controller family. FX-PCXs
expand the number of input/output points connected to
either an FX-PCA, FX-PCG, FX-PCV programmable
controller or to a supervisory controller to monitor and
control a wide variety of HVAC equipment.

FX-PCX operate on an RS-485 BACnet®

Master-Slave/Token-Passing (MS/TP) Bus as BACnet
Application Specific Controllers (B-ASCs) and integrate

into Johnson Controls® and third-party BACnet systems.

Note: At FX-PCT Release 10.1, a new capability was

introduced allowing FX-PCVs, FX-PCGs, and
FX-PCAs to communicate by using either the
BACnet or the N2 field bus networking protocol.
The operation of the FX-PCX Input/Output Module
is not affected by the selection of the BACnet or
the N2 protocol in the host controller.

North American Emissions
Compliance

the QuickLIT website for the most up-to-date version of this document.

Refer to

Installation

Observe these guidelines when installing a controller:

• Transport the controller in the original container to
minimize vibration and shock damage.

• Verify that all parts shipped with the controller.

• Do not drop the controller or subject it to physical
shock.

Parts Included

• one controller 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 (only)

• small straight-blade screwdriver for securing wires in
the terminal blocks

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.

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.

Mounting

Observe these guidelines when mounting an FX-PCX
controller:

• Ensure the mounting surface can support the
controller, DIN rail, and any user-supplied enclosure.

• Mount the controller horizontally on 35 mm DIN rail
whenever possible.

• Mount the controller in the proper mounting position.

• Mount the controller on a hard, even surface
whenever possible in wall-mount applications.

• Use shims or washers to mount the controller securely
and evenly on the mounting surface.

• Mount the controller in an area free of corrosive
vapors and observe the Ambient Conditions
requirements in Table 10.

• Provide for sufficient space around the controller for
cable and wire connections for easy cover removal
and good ventilation through the controller (50 mm
[2 in.] minimum on the top, bottom, and front of the
controller).

1FX-PCX2721 Expansion Input/Output Module Installation Instructions

• Do not mount the controller on surfaces prone to
vibration, such as duct work.

• Do not mount the controller in areas where
electromagnetic emissions from other devices or
wiring can interfere with controller communication.

Observe these additional guidelines when mounting a
controller in a panel or enclosure:

• Mount the controller so that the enclosure walls do
not obstruct cover removal or ventilation through the
controller.

• Mount the controller so that the power transformer
and other devices do not radiate excessive heat to
the controller.

• Do not install the controller in an airtight enclosure.

Figure 1: Controller Mounting Positions

DIN Rail Mount Applications

Mounting the FX-PCX controller horizontal on 35 mm DIN
rail is the preferred mounting method.

To mount a controller on 35 mm DIN rail:

1. Securely mount a 20 cm (8 in.) or longer section of
35 mm DIN rail horizontal and centered in the desired
space so that the controller mounts in the horizontal
position shown in Figure 1.

2. Pull the two bottom mounting clips outward from the
controller to the extended position (Figure 2).

3. Hang the controller on the DIN rail by the hooks at
the top of the (DIN rail) channel on the back of the
controller (Figure 2), and position the controller snugly
against the DIN rail.

4. Push the bottom mounting clips inward (up) to secure
the controller on the DIN rail.

To remove the controller from the DIN rail, pull the
bottom mounting clips out to the extended position
and carefully lift the controller off the DIN rail.

2FX-PCX2721 Expansion Input/Output Module Installation Instructions

Wall Mount Applications

To mount an FX-PCX controller directly on a wall or other
flat vertical surface:

1. Pull the two bottom mounting clips outward and
ensure they are locked in the extended position, as
shown in Figure 2.

2. Mark the mounting hole locations on the wall using
the dimensions in Figure 2 and one of the mount
positions shown in Figure 1. Or hold the controller 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 controller 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.

Figure 2: Back of Controller Showing Extended

Mounting Clips, DIN Rail Channel, and Mounting

Dimensions, mm (in.)

3FX-PCX2721 Expansion Input/Output Module Installation Instructions

Figure 3: FX-PCX2721 Physical Features

Table 1: FX-PCX2721 Physical Features Callouts and Descriptions

Physical Feature: Description and ReferencesCallout

1

3

4

5

6

7

8

9

Analog Outputs (AOs) Terminal Block. (See Table 3)

Mounting Clip (Three Total)2

Device Address DIP Switch Block (See Setting the Device Addresses)

24 VAC, Class 2 Supply Power Terminal Block (See Supply Power Terminal Block)

Cover Lift Tab (One of Two) (See Removing the Controller Cover)

Sensor Actuator (SA) Bus / Field Controller (FC) Bus Terminal Block (See SA/FC Bus Terminal Block)

Universal Inputs (UIs) Terminal Block (See Table 3)

LED Status Indicators (See Table 8)

Sensor Actuator (SA) Bus or Field Controller (FC) Bus Port (RJ-12 6-pin Modular Jack) (See SA/FC Bus Port)

4FX-PCX2721 Expansion Input/Output Module Installation Instructions

Wiring

Risk of Electric Shock: Disconnect or isolate all power

supplies before making electrical connections. More than
one disconnect 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.

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.

Terminal Blocks and Bus Ports

See Figure 3 for terminal block and bus port locations on
the controller. Observe the following guidelines when
wiring a controller.

Input and Output Terminal Blocks

All of the input terminal blocks are mounted on the bottom
of the controller and the output terminal blocks are
mounted on the top of the controller. See Table 3 for more
information about I/O terminal functions, requirements,
and ratings.

SA/FC Bus Terminal Block

An FX-PCX controller 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 FX-PCX to an FC bus, wire the bus
terminal block plugs on the controller, and the other
controllers in a daisy-chain configuration using 3-wire
twisted, shielded cable as shown in Figure 4. See Table

5 for more information.

Figure 4: FC Bus Terminal Block Wiring

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 controller electrical

ratings. Exceeding controller electrical
ratings can result in permanent damage to
the controller 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

controller components. Use proper
electrostatic discharge precautions during
installation, setup, and servicing to avoid
damaging the controller.

For detailed information on configuring and wiring an
MS/TP Bus, FC bus, and SA bus, refer to the FX-PC

Series Controllers MS/TP Communications Bus Technical
Bulletin (LIT-12011670) or MS/TP Communications Bus
for BCM System Technical Bulletin (LIT-12011908).

When connecting the FX-PCX to an SA bus, wire the bus
terminal block plugs on the controller and other SA bus
devices in a daisy-chain configuration using 4-wire
twisted, shielded cable as shown in Figure 5. See Table

3 for more information.

5FX-PCX2721 Expansion Input/Output Module Installation Instructions

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.

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 controller.

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. See Table 5 for more
information about the Supply Terminal Block.

Figure 7: 24 VAC Supply Power Terminal Block Wiring

SA/FC Bus Port

The SA/FC bus port on the front of the controller is an
RJ-12, 6-position modular jack that provides a connection

for devices on the SA bus, a Bluetooth®Commissioning
Converter, Zigbee® wireless dongle, or an FX-ZFR1811

Wireless Router (depending on which bus the FX-PCX
is operating on).

The SA/FC bus port is connected internally to the SA/FC
bus terminal block. See Table 5 for more information.
The SA/FC bus Port pin assignment is shown in Figure

6.

Figure 6: Pin Number Assignments for Sensor, SA

Bus and FC Bus Ports on Controllers

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

controller 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 controller does
not require an earth ground connection.

Wireless Network Applications

The controller can also be installed in a wireless
application using an FX-ZFR1811 Wireless Field Bus
Router.

To configure a controller for use with the FX-ZFR Series
Wireless Field Bus system:

Note: FX-PCXs can talk wirelessly on the FC bus only.

6FX-PCX2721 Expansion Input/Output Module Installation Instructions