Use this document as a guide when installing the catalog number 1771-IN ac
input module.
To :See Page:
Important User Information1
Preinstallation Considerations3
Calculate Power Requirements4
Key the Backplane Connector4
Install the Field Wiring Arm4
Connect Wiring to the Field Wiring Arm5
Interpret the Status Indicators7
Specifications8
Rockwell Automation SupportBackCover
Solid state equipment has operational characteristics differing from those
of electromechanical equipment. Safety Guidelines for the Application, Installation and Maintenance of Solid State Controls (Publication SGI-1.1
available from your local Rockwell Automation sales office or online at
http://www.ab.com/manuals/gi) describes some important differences
between solid state equipment and hard-wired electromechanical devices.
Because of this difference, and also because of the wide variety of uses for
solid state equipment, all persons responsible for applying this equipment
must satisfy themselves that each intended application of this equipment is
acceptable.
In no event will Rockwell Automation, Inc. be responsible or liable for
indirect or consequential damages resulting from the use or application of
this equipment.
The examples and diagrams in this manual are included solely for
illustrative purposes. Because of the many variables and requirements
associated with any particular installation, Rockwell Automation, Inc.
cannot assume responsibility or liability for actual use based on the
examples and diagrams.
1Publication 1771-IN082A-EN-P - February 2005
Page 2
2 AC (24V) Input Module
No patent liability is assumed by Rockwell Automation, Inc. with respect to
use of information, circuits, equipment, or software described in this
manual.
Reproduction of the contents of this manual, in whole or in part, without
written permission of Rockwell Automation, Inc. is prohibited.
Throughout this manual we use notes to make you aware of safety
considerations.
WARNING
Identifies information about practices or circumstances
that can cause an explosion in a hazardous environment,
which may lead to personal injury or death, property
damage, or economic loss.
IMPORTANT
ATTENTION
Identifies information that is critical for successful
application and understanding of the product.
Identifies information about practices or circumstances
that can lead to personal injury or death, property
damage, or economic loss. Attentions help you:
• identify a hazard
• avoid a hazard
• recognize the consequence
Publication 1771-IN082A-EN-P - February 2005
Page 3
AC (24V) Input Module 3
ATTENTION
Environment and Enclosure
This equipment is intended for use in a Pollution Degree 2
industrial environment, in overvoltage Category II
applications (as defined in IEC publication 60664-1), at
altitudes up to 2000 meters without derating.
This equipment is considered Group 1, Class A industrial
equipment according to IEC/CISPR Publication 11.
Without appropriate precautions, there may be potential
difficulties ensuring electromagnetic compatibility in other
environments due to conducted as well as radiated
disturbance.
This equipment is supplied as "open type" equipment. It
must be mounted within an enclosure that is suitably
designed for those specific environmental conditions that
will be present and appropriately designed to prevent
personal injury resulting from accessibility to live parts.
The interior of the enclosure must be accessible only by
the use of a tool. Subsequent sections of this publication
may contain additional information regarding specific
enclosure type ratings that are required to comply with
certain product safety certifications.
See NEMA Standards publication 250 and IEC
publication 60529, as applicable, for explanations of the
degrees of protection provided by different types of
enclosure. Also, see the appropriate sections in this
publication, as well as the Allen-Bradley publication
1770-4.1 ("Industrial Automation Wiring and Grounding
Guidelines"), for additional installation requirements
pertaining to this equipment.
Preinstallation
Considerations
ATTENTION
This module contains filtering to limit the effects of voltage transients caused
by contact bounce and/or radiated electrical noise. The delay due to filtering is
nominally 18ms (
This module is designed to operate with ac proximity switches and other input
devices with an off-state leakage current less than 2.8mA peak.
Preventing Electrostatic Discharge
This equipment is sensitive to electrostatic discharge, which
can cause internal damage and affect normal operation.
Follow these guidelines when you handle this equipment:
• Touch a grounded object to discharge potential static.
• Wear an approved grounding wriststrap.
• Do not touch connectors or pins on component
boards.
• Do not touch circuit components inside the equipment.
• If available, use a static-safe workstation.
+10ms) for turning ac inputs on or off.
Publication 1771-IN082A-EN-P - February 2005
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4 AC (24V) Input Module
Calculate Power
Requirements
Key the Backplane
Connector
ATTENTION
Observe the following precautions when inserting or removing keys:
• insert or remove keys with your
fingers
• make sure that key placement is
correct
Incorrect keying or the use of a tool can
result in damage to the backplane connector
and possible system faults.
The module receives its power through the 1771 I/O chassis backplane from
the chassis power supply. The module requires 80mA from the output of this
supply .
Add this current to the requirements of all other modules in the I/O chassis to
prevent overloading the chassis backplane and/or backplane power supply.
ATTENTION
Do not insert or remove modules from the I/O chassis
while system power is applied. Failure to observe this rule
could result in:
• module damage or degradation of performance
• injury or equipment damage due to possible
unexpected operation.
Place your module in any slot in the chassis except the leftmost slot which is
reserved for processors or adapters.
Position the keying bands in the backplane connectors to
correspond to the key slots on the module.
I/O chassis
Place the keying bands:
– between 4 and 6
between 10 and 12
–
Install the Field Wiring Arm
Publication 1771-IN082A-EN-P - February 2005
ATTENTION
Upper
Connector
You can change the position of these bands if
subsequent system design and rewiring makes
insertion of a different type of module necessary.
Remove power from the 1771 I/O chassis backplane and
field wiring arm before removing or installing the I/O
module. Failure to remove power from the backplane or
wiring arm could cause:
• module damage, degradation of performance, or
injury.
• injury or equipment damage due to possible
unexpected operation.
Page 5
Place the module in the card guides on the top and bottom of the
1
chassis that guide the module into position.
Important: Apply firm even pressure on the module to seat it
into its backplane connector .
1771-A1B, -A2B, -A3B, -A4B I/O chassis
AC (24V) Input Module 5
1771-A1B, -A2B, -A4B Series B I/O chassis
Snap the chassis latch over
the top of the module to
secure it.
Attach the wiring arm (1771-WA) to the horizontal bar
2
at the bottom of the I/O chassis.
The wiring arm pivots upward and connects with the
module so you can install or remove the module
without disconnecting the wires.
Swing the chassis locking bar
down into place to secure the
modules. Make sure the
locking pins engage.
1771-WA
Connect Wiring to the Field
Wiring Arm
The 1771-IN module is a modular component of the 1771 I/O system
requiring a properly installed system chassis. Refer to publication 1771-IN075
for detailed information on acceptable chassis, proper installation, and
grounding requirements. Limit the maximum adjacent slot power dissipation
to 10W maximum.
Make wiring connections to the module through the 10 terminal field wiring
arm (cat. no. 1771-WA). The arm pivots on the I/O chassis to connect with
terminals on the front of the module and acts as a terminal strip. The wiring
arm allows the module to be removed from the chassis without disconnecting
the wiring.
Publication 1771-IN082A-EN-P - February 2005
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6 AC (24V) Input Module
ATTENTION
Remove power from the 1771 I/O chassis backplane and
field wiring arm before removing or installing the I/O
module.
• Failure to remove power from the backplane or wiring
arm could cause module damage, degradation of
performance, or injury.
• Failure to remove power from the backplane could
cause injury or equipment damage due to possible
unexpected operation.
1. Make certain all power is removed from the module before making
wiring connections.
2. Swing the wiring arm up into position on the front of the module. The
locking tab on the module will secure it into place.
IMPORTANT
The field wiring arm terminal identification number is not
the same as the number of the bit which controls that
output
L1
Not used
Input 0
Input 1
Input 2
Input 3
Input 4
Input 5
Input 6
Input 7
(Actual wiring runs in this direction.)
A
O
1
2
3
4
5
6
7
L2
B
24V AC High
L2
AC Low
1902-I
1
3. Connect one terminal of your 2-wire input device to terminals 0 thru 7.
Use stranded 14 or 16 AWG (2.0-1.5mm
2
) to minimize the voltage drop
over long cable distances.
Publication 1771-IN082A-EN-P - February 2005
Page 7
AC (24V) Input Module 7
4. Connect terminal B to the L2 (low) ac return. Terminal A is not used.
Use stranded 14 or 16 AWG (2.0-1.5mm
2
) to minimize the voltage drop
over long cable distances
.
ATTENTION
AC (24V)
Output Module
(Cat. No. 1771-ON)
A
L1
O
1
2
3
4
5
6
7
L2
8
You can use an ac (24V) output module (cat. no. 1771-ON)
to directly drive terminals on an ac (24V) input module
(cat. no. 1771-IN), but you must connect a 250Ω, 5W
resistor between the output terminal and L2 (common) as
shown in the following figure. Use the same ac power
source to power both modules to ensure proper
phasing and prevent module damage.
AC (24V)
Input Module
(Cat. No. 1771-IN)
L1
AC High
Typically
250 ohm
5 Watt
Resistor
A
O
1
2
3
4
5
6
7
8
Interpret the Status
Indicators
L2
AC Low
11903-I
The front panel of your module contains 8 red status indicators (below). The
red status indicators are on when the associated output is on.