Rockwell Automation Allen-Bradley Guardmaster MSR41 User manual

User Manual Original Instructions
MSR41 Safety Module
Bulletin Number 440R

2Rockwell Automation Publication 440R-UM006B-EN-P - July 2022
MSR41 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-UM006B-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
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Application Restrictions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Chapter 2
System Configuration Terminal Connection Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Status Outputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Status Indicator Display Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Response Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Calculate the Response Time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Chapter 3
Installation Mounting Location. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Cable and Wires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Supply Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Earth Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Micro400 Safety Light Curtain Connection . . . . . . . . . . . . . . . . . . . . . . . . 13
Start Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Manual Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Automatic Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Output Monitoring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Chapter 4
Maintenance Inspection and Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Decommission. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Appendix A
Specifications Technical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Catalog Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Product Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Approximate Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Declaration of Conformity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
CE Conformity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
UKCA Conformity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Appendix B
Accessories Additional Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

4Rockwell Automation Publication 440R-UM006B-EN-P - July 2022
Table of Contents
Notes:

Rockwell Automation Publication 440R-UM006B-EN-P - July 2022 5
Preface
About This Publication This manual covers the installation and operation of the Guardmaster® MSR41
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: MSR41 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 to be used with the MSR41 safety 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 6 19
Updated Figure 7 20
Updated Declaration of Conformity 21
Resource Description
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-UM006B-EN-P - July 2022
Preface
Notes:

Rockwell Automation Publication 440R-UM006B-EN-P - July 2022 7
Chapter 1
Introduction
General Description The MSR41 is a compact safety module. This main controlling safety module
allows the connection and the control of the compact GuardShield™ Micro400
Safety Light Curtain systems.
Figure 1 - MSR41 Safety Module and GuardShield Micro400 Safety Light Curtain
The safety module offers two safety PNP outputs (OSSD). Additional MSR45E
extension modules can be applied for applications that require more outputs
and/or dry contacts to switch loads.
Special Features The characteristics of the MSR41 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
•Modularexpansible
• Up to three extension modules per main safety module
• Different start modes by hardware selectable
Typical Applications MSR41 safety modules are developed and conceived for typical applications
such as:
• Robotic cells
•Assemblylines
• Indexing tables
•Conveyorsystems
• Automatic storage facilities
Safety Light Curtain Main Safety Module
Extension Module

8Rockwell Automation Publication 440R-UM006B-EN-P - July 2022
Chapter 1 Introduction
Application Restrictions
MSR41 safety modules are not intended for application in explosive (EX) or in
radioactive environments.

Rockwell Automation Publication 440R-UM006B-EN-P - July 2022 9
Chapter 2
System Configuration
Terminal Connection
Diagrams
Figure 2…Figure 6 on page 10 show the connection possibilities for the MSR41
safety module to the Micro400 safety light curtain.
Figure 2 - Automatic Start, No Output Monitoring
Figure 3 - Manual Start, No Output Monitoring
DIN Rail
Receiver
Emitter
DIN Rail
Receiver
Emitter
Reset

10 Rockwell Automation Publication 440R-UM006B-EN-P - July 2022
Chapter 2 System Configuration
Figure 4 - Manual Start, Output Monitoring
Figure 5 - Automatic Start, Output Monitoring
Figure 6 - With MSR45E Extension Module, Automatic Start, Output Monitoring
DIN Rail
Receiver
Emitter
Reset
DIN Rail
Receiver
Emitter
DIN Rail
Receiver
Emitter

Rockwell Automation Publication 440R-UM006B-EN-P - July 2022 11
Chapter 2 System Configuration
Status Outputs The MSR41 safety module has two status outputs (Info1 and Info2). See Table 1
for a description of these outputs.
Table 1 shows the logic of the two status outputs. Status indicators show the
state of the status outputs, which are visible on the front side of the main
module.
Status Indicator Display
Elements
Table 2 shows information about the status indicator on the front side of an
MSR41 safety module with the basic configuration.
Response Time
Calculate the Response Time
• The response time of an MSR41 safety module depends on the length and
resolution of the connected GuardShield™ Micro400 safety light curtain.
• The response time for the MSR41 safety module [t(totLCOSSD)]
concerning the Micro400 safety light curtain is the sum of the safety
module response time t(C) + the response time of the safety light curtain
t(LC):
t(totLCOSSD) = t(C) + t(LC)
Table 1 - 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.
Table 2 - Status Indicator Description
Status
Indicator
Description Description
Signal Color Status Signal Color Status
OSSD2 +24V Green Safety light curtain not activated
(free) 0V Red Safety light curtain activated (interrupted)
OSSD1 +24V Green Safety light curtain not activated
(free) 0V Red Safety light curtain activated (interrupted)
Info2 See Table 1 See Table 1
Info1 See Table 1 See Table 1
IN2 +24V Green Start release OK 0V Red No start release signal
IN1 - Green Not used - Green Not used
0V - -
+24V +24V Green Power connected 0V Off No power connected
Table 3 - Response Time Calculation Terminology
Symbol Description
t(C) Response time for the MSR41 safety module (evaluation time)
t(LC) Response time of the safety light curtain (on its label)
t(em) Response time for the MSR45E extension module
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

12 Rockwell Automation Publication 440R-UM006B-EN-P - July 2022
Chapter 2 System Configuration
• The response time for the MSR45E extension module (relay safety
output) [t(totLCEXT)] concerning the Micro400 safety light curtain is the
sum of the safety module response time
t(totLCOSSD) + the response time of the expander module
t(em):
t(totLCEXT) = t(totLCOSSD) + t(em)
= t(C) + t(LC) + t(em)
The total response time of a system is the sum of each response time.
Table 4 - Total Response Time of the Micro400 Safety Light Curtain
Unit Description Calculation
MSR41 safety module Max OSSD response time for
Micro400safety light curtain t(totLCOSSD) = 9.10 ms(t(c)) + t(LC) (1)
(1) From the label of the Micro400 safety light curtain.
First…third
extension module Max relay extension module response time for Micro400 safety light curtain t(totLCEXT) = 9.10 ms(t(c)) + 6.00 ms(t(em)) + t(LC) (1)

Rockwell Automation Publication 440R-UM006B-EN-P - July 2022 13
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).
Take into full consideration the requirements of the safety regulations of
electrical engineering, the liability insurance association of the local employer,
and the international standard IEC 60204.
Mounting Location Mount MSR41 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 MSR41 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 MSR4xmodule 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.
Start Mode The following start modes are supported by the MSR41 safety module:
• Automatic start
• Manual start

14 Rockwell Automation Publication 440R-UM006B-EN-P - July 2022
Chapter 3 Installation
Manual Start
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.
Automatic Start
If the MSR41 safety module is configured for automatic start, after the
activation and the deactivation of the Micro400 safety light curtain, the two
OSSD outputs change automatically from low to high again. Also, if connected,
the MSR45E extension module contacts automatically reclose.
Output Monitoring Often an MSR41 safety module connects to external relays. This configuration
is done because the relays of the extension modules do not have enough
contacts, or if the required switching capacity is more than the specified
capacity.
These external relays can be connected in one or both ways:
1. To the two safety PNP outputs (OSSD) of the safety module (see Figure 5
on page 10)
2. To the contacts of an expander module (for example, if the power of the
two OSSD outputs is not adequate)
In any case, when using external relays, you must monitor the function of
these external relays. For category 4 application, insert two external
contactors, each with force guided contacts. To monitor the function of these
contactors, each relay block must have at least one N.C. contact, which is fed
back in series to the corresponding terminal of the MSR41 safety module.
Output monitoring: The signal at the corresponding input terminal must be
high before you press the start button (meaning that the N.C. contacts of the
external relays must close before allowing a start).
ATTENTION: The start function is not monitored (no edge detection). Take
additional measures to fulfill the requirements of a manual monitored reset,
according to the safety standards (for example, use an additional MSR127
safety relay).
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 MSR41 safety
module is configured with an automatic start, take further measures to fulfill
this requirement.

Rockwell Automation Publication 440R-UM006B-EN-P - July 2022 15
Chapter 3 Installation
Surge suppressors can drastically increase the off-delay time of the contactors.
For this reason, do not use diodes as surge suppressors.
IMPORTANT • In cases where you install the MSR41 safety module without extension
modules, the function output monitoring must always be realized. The
only exceptions are if the PNP outputs connect with another safety relay
or a safety PLC.
•Use output monitoring 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 5 - Recommended Surge Suppressors
Supply voltage [V] Resistor R [Ω] Condenser C [µF]
24 100 2.2
115...230 220 0.2

16 Rockwell Automation Publication 440R-UM006B-EN-P - July 2022
Chapter 3 Installation
Notes:

Rockwell Automation Publication 440R-UM006B-EN-P - July 2022 17
Chapter 4
Maintenance
Inspection and Service The MSR41 safety module has no serviceable components.
Inspection Qualified and trained personnel must periodically test the MSR41 safety
module, in accordance with valid regulations, to discover prohibited
manipulations or unauthorized modifications.
Decommission Only remove the MSR41 safety modules when the machine or the equipment is
shut down completely and can no longer operate without tools. Dismantle a
controller if disposal is necessary. The separated materials can be recycled
according to state-of-the-art technology and the corresponding regulations of
the country where the unit is used.

18 Rockwell Automation Publication 440R-UM006B-EN-P - July 2022
Chapter 4 Maintenance
Notes:

Rockwell Automation Publication 440R-UM006B-EN-P - July 2022 19
Appendix A
Specifications
Technical Specifications
Table 6 - Technical Specifications
Attribute Value
Probability of a dangerous failure per hour PFH
6.0 E-9 1/h: MSR42 safety module, MSR45E extension module, and Micro400
safety light curtain
9.0 E-10 1/h: MSR42 and MSR41 safety module
3.0 E-10 1/h: MSR45E extension module
4.0 E-9 1/h: Micro400 safety light curtain
Performance Level PL PLe, Cat. 4 (EN ISO 13849-1)
Safety Integrity Level SIL CL 3 (IEC 61508/IEC 62061)
Approvals CE Marked for all applicable EU directives, UKCA marked for all applicable regulations, cULus Listed, TÜV Certified
rok.auto/certifications
General
Nominal working mode Continuous process
Temperature • Environmental: 0…55 °C (32…131 °F) • Storage: -25…+70 °C (-13…+158 °F)
• Operating: 0…55 °C (32…131 °F)
Enclosure rating (EN 60529) •Housing:IP20
• Terminals: IP20
Conductor connection 4-pin, terminal strip (plug-in)
Wire cross section: Max 2.5 mm2(14 AWG) spring clamping technology
Mounting • Standard: 35mm (1.38 in.) DIN Rail
• Quick mount: 35 mm (1.38 in.) top hat rail (EN 50022) 6
Weight 130 g (0.29 lb)
Housing dimensions 111 mm x 22.5 mm x 125 mm(4.37 in. x 0.89 in. x 4.92 in.) (including plugs), see
Approximate Dimensions on page 21
Enclosure protection rating IP20
Housing material Polyamide
Conductor size, max 1 x 2.5 mm2(14 AWG) stranded
Vibration (EN60068-2-6) • Amplitude: 0.35 mm (0.1 in.)
• Frequency: 10…55 Hz
Shock resistant (EN 60068-2-29) • Acceleration: 100 ms-2
• Impulse length: 16 ms
• Number of shocks: 1000 per direction
Installation position No restrictions
Shipping
Packaging 280 mm x 200 mm x 70 mm (11.02 in. x 7.87 in. x 2.76 in.)
Net shipping weight + 220 g (8.66 in.)
Inputs
Power supply (UN)+24V DC (EN 60204-1), see Supply Voltage on page 13
at 5% residual ripple 0.85…1.15 UN
Current consumption Current max 70 mA + 70 mA per relay extension module (semi conductor
outputs unloaded) maximal: 1.7 A depending on attached load
Max power consumption at max supply voltage 2.1 W (semiconductor outputs unloaded)
Controller protection (external) 5 A slow
Control current into IN 1, IN 2 2 mA each (min) (in accordance with EN 61131-2)
Minimum voltage at IN 1, IN 2 11V DC at activated controller (EN 61131-2)
Start pulse duration, min 50 ms
Cable length, max Safety switches: 50 m (164.04 ft) out and back [total 100 m (328.08 ft)]

20 Rockwell Automation Publication 440R-UM006B-EN-P - July 2022
Appendix A Specifications
Catalog Numbers
Product Labels The necessary safety information is found on the product label, which is on
every MSR41 safety module.
Figure 7 - Example Product Label
Outputs
Voltage Info 1, Info 2 status outputs (PNP)/OSSD semi conductor outputs (PNP): UN– 2V
Current, max • Info 1, Info 2 Status Outputs (PNP): 100 mA (short-circuit protected) • OSSD semi conductor outputs (PNP): 400 mA short-circuit protected and
with cross fault detection
Leakage current • Info 1, Info 2 Status Outputs (PNP): IMAX Off = 0.5 mA (CLOAD = 4.7 µF)
• OSSD semi conductor outputs (PNP): IMAX Off = 0.1 mA (CLOAD = 3.3 µF)
Table 6 - Technical Specifications (Continued)
Attribute Value
Table 7 - Catalog Numbers
Cat. No. (1)
(1) All series are covered.
Description
440R-P221AGS
MSR41 On/Off Safety Module
• Mounting: 35 mm (1.34 in.) DIN Rail
• Size: 22.5 mm (0.98 in.)
440R-P226AGS-NNR MSR42 Start/Restart Safety Module
• Mounting: 35 mm (1.34 in.) DIN Rail
• Size: 22.5 mm (0.98 in.)
445L-104794-Bxxx (2)
(2) x = Customer configurable options that do not impact the standards or directives cited in Declaration of Conformity on
page 21.
440-P4NANS MSR45E Safety Relay Extension Module (optional)
• Input voltage: Supplied by MSR41 or MSR42 safety module
• Reset: Determined by MSR41 or MSR42 safety module
•Outputs:TwoN.O.
445L-1xxxx (2)
Table 8 - Product Label Explanation
Symbol Description
HW Hardware version
Safety Level Cat. Safety category according to EN 954-1
Safety Level SIL Safety integrity level according to EN 61508
Safety Level PLe Performance level according to EN ISO 13849-1
Power class Power supply
Temperature range Operating temperature range
OSSD Maximum current available per OSSD output, at the listed voltage