Rockwell Automation Allen-Bradley 1769-ASCII User manual

Compact I/O ASCII Module
Catalog Numbers 1769-ASCII
User Manual

Important User Information
Read this document and the documents listed in the additional resources section about installation, configuration, and
operation of this equipment before you install, configure, operate, or maintain this product. Users are required to
familiarize themselves with installation and wiring instructions in addition to requirements of all applicable codes, laws,
and standards.
Activities including installation, adjustments, putting into service, use, assembly, disassembly, and maintenance are required
to be carried out by suitably trained personnel in accordance with applicable code of practice.
If this equipment is used in a manner not specified by the manufacturer, the protection provided by the equipment may be
impaired.
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.
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, when necessary, we use notes to make you aware of safety considerations.
Labels may also be on or inside the equipment to provide specific precautions.
Allen-Bradley, Rockwell Software, Rockwell Automation, Compact I/O, CompactLogix, Logix5000, MicroLogix, RSLogix, Studio 5000 Logix Designer, and Studio 5000 are trademarks of Rockwell Automation, Inc.
Trademarks not belonging to Rockwell Automation are property of their respective companies.
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.
ATTENTION: 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, and recognize the consequence.
IMPORTANT
Identifies information that is critical for successful application and understanding of the product.
SHOCK HAZARD: Labels may be on or inside the equipment, for example, a drive or motor, to alert people that dangerous
voltage may be present.
BURN HAZARD: Labels may be on or inside the equipment, for example, a drive or motor, to alert people that surfaces may
reach dangerous temperatures.
ARC FLASH HAZARD: Labels may be on or inside the equipment, for example, a motor control center, to alert people to
potential Arc Flash. Arc Flash will cause severe injury or death. Wear proper Personal Protective Equipment (PPE). Follow ALL
Regulatory requirements for safe work practices and for Personal Protective Equipment (PPE).

Rockwell Automation Publication 1769-UM012B-EN-P - January 2014 3
Summary of Changes
This manual contains new and updated information. Changes throughout this
revision are marked by change bars, as shown to the right of this paragraph.
New and Updated
Information
This table contains the changes made to this revision.
Topic Page
Rearranged content and updated warnings and attentions. Throughout
Updated configuration to include the CompactLogix™ 5370 L3 controller,
provided link to the Knowledgebase Technote # 64203. 7
Added information about the Studio 5000™ environment. 7
Updated Additional Resources. 8
Updated configuration examples. 21
Updated I/O Memory Mapping to include the new tag structures. 71
Added the Generic Module appendix. 87
Added Electronic Keying appendix. 105
Updated Technical Support links, website addresses, and phone numbers. BackCover

4Rockwell Automation Publication 1769-UM012B-EN-P - January 2014
Summary of Changes
Notes:

Rockwell Automation Publication 1769-UM012B-EN-P - January 2014 5
Table of Contents
Preface Studio 5000 Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Additional Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Example Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Chapter 1
Compact I/O ASCII Module
About the Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Environment and Enclosure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
North American Hazardous Location Approval . . . . . . . . . . . . . . . . . . . . 11
European Hazardous Location Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Install the Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Assemble the System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Minimum Space. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Panel Mount. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
DIN Rail Mount . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Replace a Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Ground the Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Connect the D-sub Connector Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Chapter 2
Configure the 1769-ASCII Module
Configure the 1769-ASCII Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Module Definition Dialog Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Controller-scoped Tags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Data Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Connect to Channel 0 of the Module in Alternating Mode . . . . . . . . . . 34
Ladder Logic Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Configure the Module Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Connect to Both Channels of the Module in Alternating Mode. . . . . . 41
Ladder Logic Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Connect to Both Channels of the 1769-ASCII Module in Simultaneous
Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Ladder Logic Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Configure the Module for Use with a MicroLogix Controller . . . . . . . . 59
Programming Example: MicroLogix 1500 Controller . . . . . . . . . . . . . . . 62
Chapter 3
I/O Memory Mapping
ASCII Module Behavior when not in Run Mode . . . . . . . . . . . . . . . . . . . 71
Alternate Mode (one channel at a time) Output File . . . . . . . . . . . . . . . . 72
Alternate Mode (one channel at a time) Input File . . . . . . . . . . . . . . . . . . 73
Simultaneous Mode
(two channels) Input File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Simultaneous Mode (two channels) Output File . . . . . . . . . . . . . . . . . . . . 75
Status Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Configuration File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Configuration File Parameter Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

6Rockwell Automation Publication 1769-UM012B-EN-P - January 2014
Table of Contents
Data Buffer Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Set Up the Data Frame Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Receive Delimiter Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Set Up the Receive Delimiters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Set Up the Transmit Delimiter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Set Up the Receive Character Buffer Length . . . . . . . . . . . . . . . . . . . . 81
Set Up the Transmit Character Buffer Length . . . . . . . . . . . . . . . . . . 82
Receive Data Padding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Byte Swap Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Transmit Serial ASCII Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Receive ASCII Serial Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Receive Timeout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
How to Send Data from the 1769-ASCII Module. . . . . . . . . . . . . . . . . . . 84
How to Receive Serial Data from the 1769-ASCII Module. . . . . . . . . . . 85
Master/Slave Handshake. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Appendix A
Configure the 1769-ASCII Module as a Generic Module . . . . . . . . . . . . .87
Appendix B
Status Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .95
Appendix C
Error Codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuration Errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Logix Designer Example Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
RSLogix 500 Error Report Example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Appendix D
ASCII Conversion Tables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Appendix E
Using Electronic Keying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Electronic Keying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Exact Match . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Compatible Keying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Disabled Keying. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Appendix F
History of Changes
1769-UM012B-EN-P September 2013. . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Index

Rockwell Automation Publication 1769-UM012B-EN-P - January 2014 7
Preface
This manual describes how to install, configure, and troubleshoot your
Compact I/O™ 1769-ASCII module. You must be able to use RSLogix™ software
and the Studio 5000 Logix Designer™ application to configure this module.
The 1769-ASCII module, a general-purpose two-channel ASCII interface,
provides a flexible network interface to a wide variety of RS-232, RS-485, and
RS-422 ASCII devices.
The 1769-ASCII module provides two independent channels of the ASCII
device interface to the 1769 Compact I/O system. Each serial channel is fully
isolated from the backplane and from each other.
Each channel provides three different media to interface with a serial device and
are automatically selected by making the correct connections to that channel’s
9-pin D-sub connector. The actual media selected is transparent to the
1769-ASCII module.
Studio 5000 Environment The Studio 5000 Engineering and Design Environment combines engineering
and design elements into a common environment. The first element in the Studio
5000 environment is the Logix Designer application. The Logix Designer
application is the rebranding of RSLogix 5000 software and will continue to be
the product to program Logix5000™ controllers for discrete, process, batch,
motion, safety, and drive-based solutions.
The Studio 5000 environment is the foundation for the future of Rockwell
Automation® engineering design tools and capabilities. It is the one place for
design engineers to develop all of the elements of their control system.
IMPORTANT
You can use the 1769-ASCII module with the following controllers:
•CompactLogix 5370 L3 and L2
•1769-L2x and 1769-L3x
•1768-L4x
•MicroLogix™ 1500
TIP
You use RSLogix500™ software to configure the 1769-ASCII module with a
MicroLogix1500 controller.

8Rockwell Automation Publication 1769-UM012B-EN-P - January 2014
Preface
Additional Resources These documents contain additional information concerning related products
from Rockwell Automation.
You can view or download publications at
http://www.rockwellautomation.com/literature/. To order paper copies of
technical documentation, contact your local Allen-Bradley distributor or
Rockwell Automation sales representative.
Example Programs To access these Logix Designer programs, see the Knowledgebase Technote #
64203 at https://rockwellautomation.custhelp.com/app/answers/detail/a_id/
64203.
Resource Description
CompactLogix 5370 L3 Controllers, Revision 20
Release Notes 1769-RN020 Describes enhancements, known anomalies, and restrictions for CompactLogix 5370 L3 controllers,
firmware revisions 20.011…20.013
Compact I/O DeviceNet Adapter User Manual,
publication 1769-UM001 Provides details regarding the installation, configuration, and operation of DeviceNet adapters.
Logix5000 Controllers ASCII Strings Programming
Manual, publication 1756-PM013 Provides details on how to manipulate ASCII strings in Logix5000 controllers.
Compact I/O DeviceNet Scanner Module User Manual,
publication 1769-UM009 Provides details regarding the installation, configuration,
and operation of DeviceNet scanners.
1768 CompactLogix L4xControllers User Manual,
publication 1768-UM001 Provides details regarding the installation, configuration, and operation of the 1768 CompactLogix Controllers,
catalog numbers: 1768-L43, 1768-L45, 1768-L45,
1768-L45S.
CompactLogix L2xUser Manual,
publication 1769-UM007 Provides details regarding the installation, configuration, and operation of the 1768 CompactLogix Controllers,
catalog numbers: 1769-L20, 1769-L30.
CompactLogix L3xUser Manual, publication
1769-UM011 Provides details regarding the installation, configuration,
and operation of the 1768 CompactLogix Controllers,
catalog numbers: 1769-L31, 1769-L32C, 1769-L32E,
1769-L35CR, 1769-L35E.
Industrial Automation Wiring and Grounding
Guidelines, publication 1770-4.1 Provides general guidelines for installing a Rockwell Automation industrial system.
Product Certifications website,
http://www.ab.com Provides declarations of conformity, certificates, and other certification details.

Rockwell Automation Publication 1769-UM012B-EN-P - January 2014 9
Chapter 1
Compact I/O ASCII Module
The 1769-ASCII module provides a flexible network interface to a wide variety
of RS-232, RS-485, and RS-422 ASCII devices.
About the Module The module provides the communication connections to the ASCII device.
Topic Page
About the Module 9
Environment and Enclosure 10
North American Hazardous Location Approval 11
European Hazardous Location Approval 12
Install the Module 13
Assemble the System 14
Ground the Module 17
Connect the D-sub Connector Pins 18
Item Description
1a Upper DIN rail latch
1b Lower DIN rail latch
2a Upper tongue-and-groove slots
2b Lower tongue-and-groove slots
3a Channel 0 isolated ASCII connector
3b Channel 1 isolated ASCII connector
4 Stationary bus connector with male pins
1a
2a
3a
3b
1b
2b
2a
2b
4

10 Rockwell Automation Publication 1769-UM012B-EN-P - January 2014
Chapter 1 Compact I/O ASCII Module
Environment and Enclosure
WARNING: 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 (6562 ft) 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 enclosure must have suitable
flame-retardant properties to prevent or minimize the spread of flame,
complying with a flame spread rating of 5VA, V2, V1, V0 (or equivalent) if non-
metallic. 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. In addition to this publication, see the following:
•Industrial Automation Wiring and Grounding Guidelines, Allen-Bradley
publication 1770-4.1, for additional installation requirements
•NEMA Standards publication 250 and IEC publication 60529, as applicable,
for explanations of the degrees of protection provided by different types of
enclosure

Rockwell Automation Publication 1769-UM012B-EN-P - January 2014 11
Compact I/O ASCII Module Chapter 1
North American Hazardous Location Approval
The following information applies when operating this
equipment in hazardous locations.
Informations sur l’utilisation de cet équipement en
environnements dangereux.
Products marked `CL I, DIV 2, GP A, B, C, D’ are
suitable for use in Class I Division 2 Groups A, B, C, D,
Hazardous Locations and nonhazardous locations
only. Each product is supplied with markings on the
rating nameplate indicating the hazardous location
temperature code. When combining products
within a system, the most adverse temperature
code (lowest `T’ number) may be used to help
determine the overall temperature code of the
system. Combinations of equipment in your system
are subject to investigation by the local Authority
Having Jurisdiction at the time of installation.
Les produits marqués `CL I, DIV 2, GP A, B, C, D’ ne
conviennent qu'à une utilisation en environnements de
Classe I Division 2 Groupes A, B, C, D dangereux et non
dangereux. Chaque produit est livré avec des
marquages sur sa plaque d'identification qui indiquent
le code de température pour les environnements
dangereux. Lorsque plusieurs produits sont combinés
dans un système, le code de température le plus
défavorable (code de température le plus faible) peut
être utilisé pour déterminer le code de température
global du système. Les combinaisons d'équipements
dans le système sont sujettes à inspection par les
autorités locales qualifiées au moment de l'installation.
WARNING:
Explosion Hazard -
• Do not disconnect equipment unless
power has been removed or the area is
known to be nonhazardous.
• Do not disconnect connections to this
equipment unless power has been
removed or the area is known to be
nonhazardous. Secure any external
connections that mate to this equipment
by using screws, sliding latches,
threaded connectors, or other means
provided with this product.
• Substitution of components may impair
suitability for Class I, Division 2.
• If this product contains batteries, they
must only be changed in an area known
to be nonhazardous.
AVERTISSEMENT:
Risque d’Explosion –
• Couper le courant ou s'assurer que
l'environnement est classé non dangereux
avant de débrancher l'équipement.
• Couper le courant ou s'assurer que
l'environnement est classé non dangereux
avant de débrancher les connecteurs. Fixer
tous les connecteurs externes reliés àcet
équipement à l'aide de vis, loquets
coulissants, connecteurs filetés ou autres
moyens fournis avec ce produit.
• La substitution de composants peut rendre
cet équipement inadapté à une utilisation en
environnement de Classe I, Division 2.
• S'assurer que l'environnement est classé non
dangereux avant de changer les piles.

12 Rockwell Automation Publication 1769-UM012B-EN-P - January 2014
Chapter 1 Compact I/O ASCII Module
European Hazardous Location Approval
European Zone 2 Certification (The following applies when the product bears the Ex
or EEx Marking.)
This equipment is intended for use in potentially explosive atmospheres as defined by
European Union Directive 94/9/EC and has been found to comply with the Essential Health and
Safety Requirements relating to the design and construction of Category 3 equipment
intended for use in potentially explosive atmospheres, given in Annex II to this Directive.
Compliance with the Essential Health and Safety Requirements has been assured by
compliance with EN 60079-15 and EN 60079-0.
WARNING:
•This equipment must be installed in an enclosure providing at least IP54
protection when applied in Zone 2 environments.
•This equipment shall be used within its specified ratings defined by Allen-
Bradley.
•Provisions shall be made to prevent the rated voltage from being exceeded by
transient disturbances of more than 40% when applied in Zone 2 environments.
•Secure any external connections that mate to this equipment by using screws,
sliding latches, threaded connectors, or other means provided with this product.
•Do not disconnect equipment unless power has been removed or the area is
known to be nonhazardous.
ATTENTION: This equipment is not resistant to sunlight or other sources of
UV radiation.

Rockwell Automation Publication 1769-UM012B-EN-P - January 2014 13
Compact I/O ASCII Module Chapter 1
Install the Module Compact I/O is suitable for use in an industrial environment when installed in
accordance with these instructions. Specifically, this equipment is intended for
use in clean, dry environments (Pollution Degree 2(1)) and to circuits not
exceeding Over Voltage Category II(2) (IEC 60664-1).(3)
(1) Pollution Degree 2 is an environment where, normally, only non-conductive pollution occurs except that occasionally a temporary
conductivity caused by condensations is to be expected.
(2) Over Voltage Category II is the load level section of the electrical distribution system. At this level, transient voltagesare controlled
and do not exceed the impulse voltage capability of the product’s insulation.
(3) Pollution Degree 2 and Over Voltage Category II are International Electrotechnical Commission (IEC) designations.
ATTENTION: 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.
When not in use, store the equipment in appropriate static-safe packaging.
WARNING: If you connect or disconnect the serial cable with power applied to
this module or the serial device on the other end of the cable, an electrical arc
can occur. This can cause an explosion in hazardous locations. Be sure that
power is removed or the area is nonhazardous before proceeding.
ATTENTION: This product is grounded through the DIN rail to chassis ground.
Use zinc-plated, yellow-chromate steel DIN rail to assure proper grounding.
The use of other DIN rail materials (for example, aluminum and plastic), which
can corrode, oxidize, or are poor conductors, can result in improper or
intermittent grounding.

14 Rockwell Automation Publication 1769-UM012B-EN-P - January 2014
Chapter 1 Compact I/O ASCII Module
Assemble the System Attach the module to the controller or an adjacent I/O module before or after
mounting. For mounting instructions, see the Panel Mount or DIN Rail Mount
sections. To work with a system that is already mounted, see Replace a Module
section.
1. Disconnect power.
2. Check that the bus lever of the module to be installed is in the unlocked
(fully right) position.
3. Use the upper and lower tongue-and-groove slots (1) to secure the
modules together or to a controller.
4. Move the module back along the tongue-and-groove slots until the bus
connectors (2) align with each other.
5. Use your fingers or a small screwdriver to push the bus lever back slightly
to clear the positioning tab (3).
6. Move the bus lever fully to the left (4) until it clicks, to enable
communication between the controller and module.
7. Verify that it is locked firmly in place.
8. Attach an end-cap terminator (5) to the last module in the system by using
the tongue-and-groove slots as before.
ATTENTION: Remove powerbefore removing or inserting this module. When
you remove or insert a module with power applied, an electrical arc can occur.
An electrical arc can cause personal injury or property damage by:
•sending an erroneous signal to your system’s field devices, causing
unintended machine motion.
•causing an explosion in a hazardous environment.
Electrical arcing causes excessive wear to contacts on both the module and its
mating connector. Worn contacts can create electrical resistance.
ATTENTION: When attaching I/O modules, it is important that the bus
connectors are securely locked together to be sure of proper electrical
connection.
6
5
4
3
1
1
2

Rockwell Automation Publication 1769-UM012B-EN-P - January 2014 15
Compact I/O ASCII Module Chapter 1
9. Lock the end-cap bus terminator (6).
Minimum Space
Maintain spacing, for example, from enclosure walls, wireways, adjacent
equipment. Allow 50 mm (2 in) of space on all sides for adequate ventilation.
Panel Mount
Mount the module to a panel by using two screws per module. Use M4 or #8
panhead screws. Mounting screws are required on every module.
Panel Mount Procedure with the Dimensional Template
IMPORTANT
You must use a 1769-ECR or 1769-ECL right- or left-end cap to terminate
the end of the serial communication bus.
ATTENTION: During panel or DIN rail mounting of all devices, be sure that all
debris (for example, metal chips and wire strands) is kept from falling into the
module. Debris that falls into the module could cause damage on powerup.
Controller
Compact I/O Compact I/O Compact I/O Compact I/O Compact I/O
End Cap
Top
Bottom
Side Side
Host Controller
Compact I/O Compact I/O Compact I/O
Right End Cap
All dimensions
are in mm (inches). Hole
spacing tolerance:
±0.4 mm (0.016 in.)
For more than 2 modules:(number of modules - 1) X 35 mm (1.38 in.)
Referto host controller documentationfor this dimension.
132
(5.197)
122.6±0.2
(4.826±0.008)
35
(1.38)
28.5
(1.12)

16 Rockwell Automation Publication 1769-UM012B-EN-P - January 2014
Chapter 1 Compact I/O ASCII Module
Panel Mount Procedure with Modules as a Template
The following procedure lets you use the assembled modules as a template for
drilling holes in the panel. Due to module mounting hole tolerance, it is
important to follow these procedures.
1. On a clean work surface, assemble no more than three modules.
2. Mark the center of all module-mounting holes on the panel by using the
assembled modules as a template.
3. Return the assembled modules to the clean work surface, including any
previously mounted modules.
4. Drill and tap the mounting holes for the recommended M4 or #8 screw.
5. Place the modules back on the panel, and check for proper hole alignment.
6. Use the mounting screws to attach the modules to the panel.
If mounting more modules, mount the last one of this group only and put
the others aside. This reduces remounting time during drilling and tapping
of the next group.
7. Repeat steps 1…6 for any remaining modules.
DIN Rail Mount
The module can be mounted on these DIN rails:
• 35 x 7.5 mm (EN 50022 - 35 x 7.5)
• 35 x 15 mm (EN 50022 - 35 x 15)
Before mounting the module on a DIN rail, close the DIN rail latches. Press the
DIN rail mounting area of the module against the DIN rail. The latches
momentarily open and lock into place.
IMPORTANT
When mounting the CompactLogix system, either use screws to panel mount
the system or use DIN rail. Do not use both. Use of both mounting methods
can cause hardware damage and cause the system to fail.

Rockwell Automation Publication 1769-UM012B-EN-P - January 2014 17
Compact I/O ASCII Module Chapter 1
Replace a Module
The module can be replaced while the system is mounted to a panel or DIN rail.
1. Remove power.
2. Remove the upper and lower mounting screws from the module to be
removed (or open the DIN latches with a screwdriver).
3. Move the bus lever to the right to disconnect (unlock) the bus.
4. Move the bus lever on the right-side adjacent module to the right (unlock)
to disconnect it from the module to be removed.
5. Gently slide the disconnected module forward.
If you feel excessive resistance, verify that the module is disconnected from
the bus and mounting screws are removed (or DIN latches opened).
If needed, rock the module slightly from front to back to remove it, or, in a
panel-mounted system, to loosen the screws of adjacent modules.
6. Before installing the replacement module, verify that the bus lever on the
replacement module and the right-side adjacent module are unlocked
(fully right) position.
7. Slide the replacement module into the open slot.
8. Connect the modules together by locking (fully left) the bus levers on the
replacement module and the right-side adjacent module.
9. Replace the mounting screws (or snap the module onto the DIN rail).
Ground the Module This product is intended to be mounted to a well-grounded mounting surface
such as a metal panel. Additional grounding connections from the module’s
mounting tabs or DIN rail (if used) are not required unless the mounting surface
cannot be grounded. See Industrial Automation Wiring and Grounding
Guidelines, publication 1770-4.1, for additional information.
ATTENTION: Remove power before removing or inserting this module. When
you remove or insert a module with power applied, an electrical arc can occur.
An electrical arc can cause personal injury or property damage by:
•sending an erroneous signal to your system’s field devices, causing
unintended machine motion
•causing an explosion in a hazardous environment
Electrical arcing causes excessive wear to contacts on both the module and its
mating connector. Worn contacts can create electrical resistance.

18 Rockwell Automation Publication 1769-UM012B-EN-P - January 2014
Chapter 1 Compact I/O ASCII Module
Connect the D-sub Connector
Pins
All the pins are always active.
Figure 1 - RS-232 Wiring Diagram - Module to DTE Device (hardware handshaking disabled)
(1) Connect to the shield of the cable.
IMPORTANT
Pins unused for a particular physical network must not be connected via the
serial cable to any other device. In particular, do not use cables 1747-CP3 and
1756-CP3.
Pin RS-232 RS-422 RS-485
1 Do Not Connect Transmit Data - Transmit/Receive Data -
2 Receive Data Do Not Connect Do Not Connect
3 Transmit Data Do Not Connect Do Not Connect
4 Do Not Connect Receive Data - Do Not Connect
5 Common Common Common
6 Do Not Connect Receive Data + Do Not Connect
7 Request To Send Request To Send Request To Send
8 Clear To Send Clear To Send Clear To Send
9 Do Not Connect Transmit Data + Transmit/Receive Data +
NC1
RXD2
TXD3
NC4
COM5
NC6
RTS7
CTS8
NC9
DCD
TXD
RSD
DSR
COM
DTR
CTS
RTS
GND
8
2
3
6
7
20
5
4
1
1
3
2
6
5
4
8
7
(1)
ASCII DTE DTE 9-pin 25-pin

Rockwell Automation Publication 1769-UM012B-EN-P - January 2014 19
Compact I/O ASCII Module Chapter 1
Figure 2 - RS-232 Wiring Diagram - Module to Printer (hardware handshaking enabled, standard
printer adapter cable)
Figure 3 - RS-422 Wiring Diagram
Figure 4 - RS-485 Wiring Diagram
NC
NC
NC
1
RXD2
TXD3
4
COM5
6
RTS7
CTS8
N.C.9
CD
TXD
RXD
DSR
COM
DTR
CTS
RTS
RI
8
2
3
6
7
20
5
4
22
1
3
2
6
5
4
8
7
9
GND 1
ASCII DTE DTE 9-pin 25-pin
ASCII
TXD-
NC
NC
1
2
3
4
COM5
RXD+
RTS
CTS
6
7
8
TXD+9
RXD-
TXD-
COM
TXD+
RXD+
RXD-
TRXD-
NC
NC
NC
NC
1
2
3
4
COM
RTS
CTS
5
6
7
8
TRXD+9
TRXD-
COM
TRXD+
ASCII

20 Rockwell Automation Publication 1769-UM012B-EN-P - January 2014
Chapter 1 Compact I/O ASCII Module
Notes: