Rockwell Automation Allen-Bradley MSR42 User manual

User Manual Original Instructions
MSR42 Safety Module
Bulletin Number 440R

2Rockwell Automation Publication 440R-UM008B-EN-P - July 2022
MSR42 Safety Module 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.
These labels may also be on or inside the equipment to provide specific precautions.
The following icon may appear in the text of this document.
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).
Identifies information that is useful and can help to make a process easier to do or easier to understand.

Rockwell Automation Publication 440R-UM008B-EN-P - July 2022 3
Table of Contents
About This Publication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Summary of Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Additional Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Chapter 1
Introduction General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Special Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Customer Configurations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Application Restrictions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Chapter 2
System Configuration Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Basic Configurations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Customer Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Status Outputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Status Indicator Display Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Response Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Micro400 Safety Light Curtain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Other Safety Components Connected to GPIO Terminals. . . . . . . . 15
MSR45E Extension Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Basic Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Chapter 3
Installation Mounting Location. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Cable and Wires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Supply Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Earth Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Micro400 Safety Light Curtain Connection . . . . . . . . . . . . . . . . . . . . . . . . 17
Start Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Manual Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Automatic Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Minimum Off Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
EDM or Start Release. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Safety Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Safety Override . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
OSSD Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Muting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Blanking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Blanking Teach-In . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Single Scan Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Test the MSR42 Safety Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Chapter 4
Maintenance Diagnostic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

4Rockwell Automation Publication 440R-UM008B-EN-P - July 2022
Table of Contents
External Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Internal Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Decommission. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Appendix A
Specifications Technical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Catalog Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Product Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Approximate Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Declaration of Conformity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
CE Conformity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
UKCA Conformity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Appendix B
Accessories Additional Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Interrupt Ignore Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Rockwell Automation Publication 440R-UM008B-EN-P - July 2022 5
Preface
About This Publication This manual covers the installation and operation of the Guardmaster® MSR42
Safety Module.
Summary of Changes This publication contains the following new or updated information. This list
includes substantive updates only and is not intended to reflect all changes.
Additional Resources These documents contain additional information concerning related products
from Rockwell Automation.
You can view or download publications at rok.auto/literature.
ATTENTION: MSR42 safety modules can only achieve functionality if the
instructions and additional documentation that are given in this instruction
manual are exactly followed. You must also consult the valid laws and
regulations at the time of installation. Serious injury or death can occur if you
do not follow these instructions carefully. The installer or system integrator is
fully responsible for a safe integration of this product. This instruction
manual is part of the MSR45E extension module. This instruction must be
accessible together with the other machine documentation during its entire
lifecycle for all personnel responsible for assembly, installation, operation,
and maintenance.
Topic Page
Added UKCA Approvals to Table 2 15
Updated Figure 13 31
Updated Declaration of Conformity 32
Resource Description
Light Curtains Configuration and Diagnostic Software Tool User Manual,
publication SAFETY-UM001 Provides information to configure and diagnose GuardShield™ safety light curtains and
MSR42 safety module products.
System Security Design Guidelines Reference Manual, SECURE-RM001 Provides guidance on how to conduct security assessments, implement Rockwell Automation products in a secure system, harden the control system, manage user access,
and dispose of equipment.
UL Standards Listing for Industrial Control Products,
publication CMPNTS-SR002 Assists original equipment manufacturers (OEMs) with construction of panels, to help
confirm that they conform to the requirements of Underwriters Laboratories.
Industrial Components Preventive Maintenance, Enclosures, and Contact
Ratings Specifications, publication IC-TD002 Provides a quick reference tool for Allen-Bradley industrial automation controls and
assemblies.
Safety Guidelines for the Application, Installation, and Maintenance of
Solid-state Control, publication SGI-1.1
Designed to harmonize with NEMA Standards Publication No. ICS 1.1-1987 and provides
general guidelines for the application, installation, and maintenance of solid-state control in
the form of individual devices or packaged assemblies incorporating solid-state
components.
Industrial Automation Wiring and Grounding Guidelines, publication 1770-4.1 Provides general guidelines for installing a Rockwell Automation industrial system.
Product Certifications website, rok.auto/certifications. Provides declarations of conformity, certificates, and other certification details.

6Rockwell Automation Publication 440R-UM008B-EN-P - July 2022
Preface
Notes:

Rockwell Automation Publication 440R-UM008B-EN-P - July 2022 7
Chapter 1
Introduction
General Description The MSR4xis a family of compact safety control modules. This main
controlling module allows the connection and the control of the compact
Allen-Bradley® GuardShield™ Micro400 Safety Light Curtain systems.
Depending on the configuration, other safety components can also be
connected and monitored simultaneously.
Figure 1 - MSR42 Safety Module and Safety Components
The MSR41 safety module or MSR42 safety module offer two safety PNP
outputs (OSSD). Additional MSR45E extension modules can be applied, which
require relay contact outputs.
You can attach up to three extension modules, which the base module controls.
We also offer models in special configurations, which are described in
Interrupt Ignore Time on page 36.
Special Features The characteristics of the MSR42 safety module:
• Category 4, PLe according to EN ISO 13849-1
• Type 4 according to EN 61496-1/-2
• SIL 3 according to IEC 61508
• SIL CL 3 according to EN 62061
•Shortresponsetimes
• Expandable
• Up to three extension modules per main safety module
• Adjustable stop delay time
• Different safety components suitable for connection
Safety Light Curtain
Main Safety Module
Extension Module

8Rockwell Automation Publication 440R-UM008B-EN-P - July 2022
Chapter 1 Introduction
•Blanking
• Muting
• Single scan selectable
Customer Configurations The configuration of an MSR42 safety module can adapt to the customer
requirements of an individual application with the use of the USB/optical
interface and the Allen-Bradley Guardmaster® software Configuration and
Diagnostic Tool. More information is in publication SAFETY-UM001. The
software generates a configuration control document that lists the
configurations and specifications of the controller and safety light curtain.
Typical Applications Typical MSR42 safety module applications are:
•Presses
• Robotic cells with automatic insertion
•Assemblylines
• Indexing tables
•Conveyorsystems
• Automatic storage facilities
Application Restrictions
MSR42 safety modules are not intended for application in explosive (EX) or in
radioactive environments.
WARNING: The resolution and the response time can increase due to the
download of other configuration settings for the Micro400 safety light curtain
and other safety sensors that are connected to an MSR42 safety module.
Consider the relevant resolution and the maximum response time when you
evaluate the safety distance. See Response Time on page 13. All relevant data of
the actual configuration are described in the configuration control document for
that controller. Always store the document near to the control unit.

Rockwell Automation Publication 440R-UM008B-EN-P - July 2022 9
Chapter 2
System Configuration
Wiring Diagrams Basic Configurations
Figure 2…Figure 6 on page 11 show the connection possibilities for the MSR42
safety module with basic configuration. The logic of this basic version is
exemplified in the configuration control document. See Blanking Teach-In on
page 23.
Figure 2 - Basic Configuration, Manual Start
Table 1 - Connection Configurations
Figure Safety Component Start Mode Start Release
Figure 2 Micro400 safety light curtain Manual No
Figure 3 on page 10 Micro400 safety light curtain Manual Yes
Figure 4 on page 10 Micro400 safety light curtain Automatic No
Figure 5 on page 11 Micro400 safety light curtain Automatic Yes
DIN Rail
Receiver
Emitter
Start

10 Rockwell Automation Publication 440R-UM008B-EN-P - July 2022
Chapter 2 System Configuration
Figure 3 - Basic Configuration, Manual Start, with Start Release
Figure 4 - Basic Configuration, Automatic Start
DIN Rail
Receiver
Emitter
Start
DIN Rail
Receiver
Emitter

Rockwell Automation Publication 440R-UM008B-EN-P - July 2022 11
Chapter 2 System Configuration
Figure 5 - Basic Configuration, Automatic Start, with Start Release
Figure 6 - With MSR45E Extension Module, Basic Configuration, Automatic Start, with Start Release
DIN Rail
Receiver
Emitter
DIN Rail
Receiver
Emitter

12 Rockwell Automation Publication 440R-UM008B-EN-P - July 2022
Chapter 2 System Configuration
Customer Configurations
The configuration of an MSR42 safety module is configured via of the USB/
optical interface and the Allen-Bradley® GuardShield™ software Configuration
and Diagnostic Tool. The configuration procedure is in publication
SAFETY-UM001. Configuration details are in the specific configuration
control document for the MSR42 safety module.
The following features are selectable:
•Stopdelay
• Single scan for faster response times
• Configuring GPIO terminals for one or two safety inputs
• Configuring GPIO terminals for E-stop or door switch
• Safety override
• Muting
•Blanking
Authorized personnel must use the USB/optical interface (catalog number
445L-AF6150) to download a new configuration to the MSR42 safety module.
Status Outputs The MSR42 safety module has two status outputs (Info1 and Info2). The logic
of these two outputs depends on the configuration. A description of these
outputs is given in the configuration control document.
Table 2 shows the logic of the two status outputs for the basic configuration.
Status indicators, which are visible on the front side of the main module, show
the state of the status outputs.
WARNING: If authorized personnel reconfigure the safety module with the USB/
optical interface, the response time or the stop delay time t(delay) can increase,
depending on the configuration. Execute the following steps for every new
configuration.
1. Place the configuration change label (see Figure 14 on page 31) on the control
module.
2. Confirm that the new response time is within the limits that are given by the
risk analysis of the machine.
3. All relevant data of the actual configuration are described in the
configuration control document for that controller. Always store the
document near to the control unit.
4. The use of the Blanking mode reduces the resolution of the Micro400 safety
light curtain. Label the Micro400 safety light curtain with the new resolution.
A label is supplied with the Micro400 safety light curtain mounting kit.
Table 2 - Status Outputs
Terminal (Status Indicator) Output High (+24V) Output Low (0V)
Info1 Green: Start OK Red: No start possible
Info2 Green: System OK Red: Error (lock out)
ATTENTION: These outputs cannot perform any safety relevant functions.
They serve only to communicate the status to a machine controller.

Rockwell Automation Publication 440R-UM008B-EN-P - July 2022 13
Chapter 2 System Configuration
Status Indicator Display
Elements
Table 3 shows information about the status indicator on the front side of an
MSR42 safety module with basic configuration.
Response Time General
The response time of an MSR42 safety module depends on the configuration.
Use the following formulas to calculate the relevant maximum response times
for the MSR42 safety module, concerning a specific Micro400 safety light
curtain, MSR45E extension module, and a specific safety component.
The response time can increase if a stop delay time t(delay) is configured for a
safety component or a Micro400 safety light curtain. During this delay, all start
impulses are ignored. The safety outputs switch off at the end of this delay
period.
The safety module ships with the double scan filter. You can select the single
scan filter to reduce the response time. The relevant times are in the
corresponding configuration control document (see the configuration
software manual).
Table 3 - Status Indicator Description
Status Indicator Description Description
Signal Color Status Signal Color Status
Lamp - Orange Muting or blanking
activated -Off
Muting or blanking
not activated
GPIO4 +24V Green Automatic start 0V Off Manual start
GPIO3 +24V Green Manual start signal high
or automatic start 0V Off Manual start
GPIO2 +24V Green Teach-in blanking active 0V Off Teach-in blanking
inactive
GPIO1 +24V Green Teach-in blanking active 0V Off Teach-in blanking
inactive
OSSD2 +24V Green Safety light curtain not
activated 0V Red Safety light curtain
activated
(interrupted)
OSSD1 +24V Green Safety light curtain not
activated 0V Red Safety light curtain
activated
(interrupted)
Info2 See Table 2 on page 12 See Table 2 on page 12
Info1 See Table 2 on page 12 See Table 2 on page 12
IN2 +24V Green Start release OK 0V Red No start release
signal
IN1 +24V Green No test 0V Red Test
0V - -
+24V +24V Green Power connected 0V Off No power
connected

14 Rockwell Automation Publication 440R-UM008B-EN-P - July 2022
Chapter 2 System Configuration
Micro400 Safety Light Curtain
The safety light curtain response time t(LC) is a part of the response time for
the OSSD outputs. The label of the Micro400 safety light curtain shows the
worst case response time, which occurs when the MSR42 safety module runs
the active double scan filter (default). Single scan yields a faster response time,
but makes the safety light curtain more vulnerable to ambient light. The safety
light curtain response time t(LC) with the double scan filter is in the Micro400
safety light curtain manual, and with/without the double scan filter in the
configuration control document (see the configuration software manual). The
configuration control document is generated by the MSR42 safety module
software Configuration and Diagnostic Tool (see publication SAFETY-UM001).
You must enter the safety light curtain resolution and protective field height.
The response time for the MSR42 safety module (OSSD safety outputs)
concerning the Micro400 safety light curtain t(totLCOSSD) is the sum of the
controller response time t(C), the response time of the safety light curtain
t(LC), and the stop delay time t(delay) (if a delay is configured and selected for
the Micro400 safety light curtain).
Output OSSD
t(totLCOSSD) = t(C) + t(LC) + t(delay)
Output Relay Extension Module
The response time for the MSR45E extension module (relay safety output)
concerning the Micro400 safety light curtain is the sum of the OSSD response
time and the response time of the extension module.
t(totLCEXT) = t(totLCOSSD) + t(em)
Table 4 - Response Time Calculation Terminology
Symbol Description
t(C) Response time for the MSR42 safety module (evaluation time), without safety light curtain
evaluation time
t(LC) Response time of the safety light curtain (on its label)
t(delay) Stop delay time for the outputs
t(em) Response time for the MSR45E extension module
t(GPIO) Evaluation time for the safety component (GPIO filter time)
t(SCext) Response time of the external safety component (Safe4)
t(totLCOSSD) Max OSSD response time triggered by the safety light curtain
t(totLCEXT) Max relay extension module response time for the safety light curtain
t(totSCOSSD) Maximum OSSD response time for the safety components on GPIO
t(totSCEXT) Maximum relay extension module response time for the safety components on GPIO

Rockwell Automation Publication 440R-UM008B-EN-P - July 2022 15
Chapter 2 System Configuration
Other Safety Components Connected to GPIO Terminals
The response time of the MSR42 safety module OSSD safety outputs
concerning the safety components that are connected to the GPIO terminals is
the sum of the controller response time, the response time of the Micro400
safety light curtain, the safety component evaluation time, the response time
of the external connected safety components, and the stop delay time (if delay
is configured and selected for the safety components).
t(totSCOSSD) = t(C) + t(LC) + t(GPIO) + t(SCext) + t(delay)
MSR45E Extension Module
The response time for the MSR45E extension module (safety relay output)
concerning the safety components that are connected on the GPIO terminals
t(totSCEXT) is the sum of the main module response time t(totSCOSSD) and
the response time of the extension module t(em).
t(totSCEXT) = t(totSCOSSD) + t(em)
Basic Configuration
The maximum controller response time t(C) for the MSR42 safety module is
given in Response Time on page 13. However, depending on the connected
Micro400 safety light curtain, the response time can be shorter. The exact
value is in the configuration control document that is created with the
Configuration and Diagnostic Tool software (see publication SAFETY-UM001).
IMPORTANT The response can increase when authorized personnel use the USB/
optical interface (catalog number 445L-AF6150) to reconfigure the
controller, depending on the configuration. After every new
configuration, proceed according to Customer Configurations on
page 12.

16 Rockwell Automation Publication 440R-UM008B-EN-P - July 2022
Chapter 2 System Configuration
Notes:

Rockwell Automation Publication 440R-UM008B-EN-P - July 2022 17
Chapter 3
Installation
For professional installation and connection, consult the relevant laws and
regulations, the safety officer of the manufacturing facilities, and the local
authorities (OSHA in USA, HSE in Great Britain) or the respective industry
associations are available for any safety-related queries.
Consider the requirements of the safety regulations of electrical engineering,
the liability insurance association of the local employer, and the international
standard IEC 60204. This chapter describes the installation of all possible
safety components that can generally connect to an MSR42 safety module. The
corresponding configuration control document for the MSR42 safety module
informs which safety component must connect to deliver faultless
functionality.
Mounting Location Mount MSR42 safety modules in a control cabinet that is sealed to at least IP54.
Snap the units onto a grounded 35 mm (1.38 in.) mounting rail. If you use the
unit outside of a control cabinet, we recommend you use a housing with a
protection category of IP54 and a mounting rail.
Cable and Wires Securely separate the wires from the MSR42 safety module and guide the wires
away from the wires of the relay section (MSR45E extension modules).
Supply Voltage To safeguard the controller, protect the +24V terminal with an external 5 A
fuse. The controller and the machine must be offline before you begin the
installation.
The supply voltage must conform to the requirements of EN 60204-1 and must
bridge a 20 ms interruption of the supply network. The supply voltage must be
one of the following, in accordance with IEC 364-4-41:
• SELV (safety extra low voltage)
• PELV (protective extra low voltage)
Earth Connection The earth of each MSR42 safety module connects to the mounting rail.
Confirm that the mounting rail has a good earth connection.
Micro400 Safety Light
Curtain Connection
The two RJ45 sockets on the lower portion of the safety module are for the
connection of an Allen-Bradley® GuardShield™ Micro400 safety light curtain
(white = E = emitter; blue = R = receiver). To protect the RJ45 connectors, snap
the cables into the provided cable holders at the MSR42safety relay housing.

18 Rockwell Automation Publication 440R-UM008B-EN-P - July 2022
Chapter 3 Installation
Start Mode The MSR42 safety module can be configured to have the following start modes:
• Automatic start
• Manual start
With basic configuration, you can configure the start mode without the
configuration software. Automatic reset enables when you connect +24V to
GPI03 and GPI04 (see Wiring Diagrams on page 9).
Manual Start
When all inputs of the safety system have a safe signal, pressing the Start
button causes the two safety OSSD outputs to change from low to high and, if
the MSR45E extension module is connected, the modules close.
If multiple safety components are configured, then all components must have
safe signals to all inputs before a start is allowed. The Start button is monitored
to help prevent an unintentional start. Pulse length must be 50 ms…5 s. If the
start impulse is longer or shorter, the device ignores the start input. The
configuration control document identifies which terminal the Start button
connects to. If the Start button connects to IN1or IN2, a red status indicator
shows that a start signal is present, a green status indicator shows that no
signal is present.
Automatic Start
If the MSR42 safety module is configured for automatic start, after the
activation and the deactivation of the safety component, the two OSSD
outputs change automatically from low to high again. Also, if connected, the
MSR45E extension module contacts automatically reclose.
Minimum Off Time According to the standard IEC 61496-2, a safety light curtain must have a
minimum safety output off time of 80 ms. This specification means that even
if a short safety light curtain interruption occurs, the safety outputs stay low
(relays are open) for a minimum of 80 ms. A start signal is only recognized
after the 80 ms duration.
Table 5 - Status Indicator Description
Status Indicator Description Description
Color Status Color Status
IN 1 or IN 2 Green No start signal present Red Start signal present (button pressed)
ATTENTION: Mount the Start button so the dangerous area is clearly visible.
That is, confirm that when you press the Start button, no one is detained
within the dangerous area.
ATTENTION: According to EN 60204 article 9.2.4.4.2, a system cannot
automatically restart, even after the cause of the shutdown is eliminated.
Therefore, another danger can still exist to the operator. If the MSR42 safety
module is configured with an automatic start, take further measures to fulfill
this requirement.

Rockwell Automation Publication 440R-UM008B-EN-P - July 2022 19
Chapter 3 Installation
EDM or Start Release If an MSR42 safety module is used with external relays or contactors, the
contacts of that device must be monitored. An example category 4 application
has two external contactors, each with force guided contacts that must be
inserted. For monitoring the function of these contactors, each relay block
must have at least one NC contact that is fed back in series to IN2 (or IN1
depending on configuration) of the MSR42 safety module (see Figure 3 on
page 10).
Two monitoring options are possible:
1. Start release: The signal at the corresponding input terminal must be
high before the Start button is pressed. This option means the NC
contacts of the external relays must close before allowing a start. The
optional start release is pre-configured in the MSR42 safety module
(catalog number 440R-P226AGS-NNR) (see Figure 3 on page 10).
2. EDM (external device monitoring): The input signal of the EDM terminal
is always monitored. This option means that the signal must be correct,
not only at the beginning before a start. A signal change must also
happen after startup, otherwise an emergency stop occurs. If a high
signal is present for longer than 5 seconds, a lockout occurs.
If the configuration control document shows that EDM or start release must
attach to terminal IN 1 or IN 2, then the meaning of the respective status
indicator is shown in Table 6.
The start release or EDM input is not cross fault monitored and therefore not a
safety input.
Surge suppressors can drastically increase the off-delay time of the contactors.
For this reason, do not use diodes as surge suppressors.
Table 6 - Status Indicator Description
Status Indicator Description Description
Color Status Color Status
EDM at IN 1 or IN 2 Green EDM signal okay Red EDM signal wrong
Start release at
IN 1 or IN 2 Green Start release signal okay Red Start release signal wrong
IMPORTANT • In cases where you install the MSR42 safety module without extension
modules, always use the external device monitoring (EDM) or start
release, unless the PNP outputs connect with another safety module or
a safety PLC.
•Use start release or EDM to switch external power contactors within the
safety circuit. Such contactors often deal with large inductive loads,
which during the switching-off phase can create large potential peaks.
For this reason, we highly recommend surge suppressors. Surge
suppressors must connect parallel to the external contactors (see
Figure 2 on page 9). Do not connect surge suppressors parallel to the
contacts of a MSR45E extension module.
Table 7 - Recommended Surge Suppressors
Supply voltage [V] Resistor R [Ω] Condenser C [µF]
24 100 2.2
115...230 220 0.2

20 Rockwell Automation Publication 440R-UM008B-EN-P - July 2022
Chapter 3 Installation
Safety Components The connected safety components (for example, safety switches, position
switch, E-stop buttons, cable pull safety switches) must satisfy the
requirements of the safety analysis and the relevant standards for application
within safety areas:
• E-stop button: EN 418
• Safety switch: EN 60947-5-1
• Safety light curtains: EN 61496-1/-2
The components must contain two force-guided, normally closed NC contacts
(see Figure 7) that are approved for the relevant safety level or category.
As a basic rule to increase reliability, we recommend that you use safety
components with integrated gold contacts. Safety components, can be
connected to GPIO1 through GPIO4, as shown in Figure 7. The inputs are
short-circuit and cross fault monitored.
Figure 7 - E-stop Connection
In general, the two circuits of dual-channel safety components are cross fault
monitored. A short of these two circuits would lead to an emergency stop of the
MSR42 safety module. The two circuits are also time-monitored, meaning if,
for example, one circuit of an emergency stop changes, the second circuit must
follow within 5 seconds. If the second circuit does not follow in the allotted
time, the MSR42 safety module interprets this action as a fault and the
controller switches off the safety circuit.
Depending on the configuration and the application, there can be more
terminals than the components need. The unused ports can be bridged. We
recommend shielded cables for bridging to reduce the input of EMC.
Safety Override Figure 8 on page 21 shows a safety override keyswitch and a safety override
lamp. With the safety override keyswitch, you can override the safety function
of the Micro400 safety light curtain. This action means that if the override
keyswitch is activated, the safety outputs stay high even if, for example, the
protective field is interrupted.
Table 8 - Status Indicator Description
Status
Indicator
Description Description
Color Status Color Status
GPIO3 Green Contact GPIO1/GPIO3 closed Off Contact GPIO1/GPIO3 open
GPIO4 Green Contact GPIO2/GPIO4 closed Off Contact GPIO2/GPIO4 open