Pepperl+Fuchs SIL KCD2-SCS-2 User manual

ISO9001
2
Functional Safety
SMART Transmitter Power
Supply/SMART Current
Driver
KCD2-SCS-(Ex)2(.SP)
Manual

With regard to the supply of products, the current issue of the following document is applicable:
The General Terms of Delivery for Products and Services of the Electrical Industry, published by the Central
Association of the Electrical Industry (Zentralverband Elektrotechnik und Elektroindustrie (ZVEI) e.V.) in its most
recent version as well as the supplementary clause: "Expanded reservation of proprietorship"
Worldwide
Pepperl+Fuchs Group
Lilienthalstr. 200
68307 Mannheim
Germany
Phone: [phone] - 0
E-mail: [e-mail]
North American Headquarters
Pepperl+Fuchs Inc.
1600 Enterprise Parkway
Twinsburg, Ohio 44087
USA
Phone: [phone]
E-mail: [email protected].com
Asia Headquarters
Pepperl+Fuchs Pte. Ltd.
P+F Building
18 Ayer Rajah Crescent
Singapore 139942
Phone: [phone]
E-mail: [email protected]
https://www.pepperl-fuchs.com

3
Functional Safety KCD2-SCS-(Ex)2(.SP)
Contents
2022-11
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1 Content of this Document . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2 Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.3 Symbols Used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2 Product Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1 Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2 Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.3 Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.4 Standards and Directives for Functional Safety . . . . . . . . . . . . . . . . . . . 9
3 Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.1 System Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.2 Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.3 Safety Function and Safe State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.4 Characteristic Safety Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.5 Useful Lifetime . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4 Mounting and Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.1 Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.1 Proof Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6 Maintenance and Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
7 List of Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Functional Safety KCD2-SCS-(Ex)2(.SP)
Contents
4
2022-11

Functional Safety KCD2-SCS-(Ex)2(.SP)
Introduction
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1 Introduction
1.1 Content of this Document
This document contains information for usage of the device in functional safety-related
applications. You need this information to use your product throughout the applicable stages
of the product life cycle. These can include the following:
•Product identification
•Delivery, transport, and storage
•Mounting and installation
•Commissioning and operation
•Maintenance and repair
•Troubleshooting
•Dismounting
•Disposal
The documentation consists of the following parts:
•Present document
•Instruction manual
•Manual
•Datasheet
Additionally, the following parts may belong to the documentation, if applicable:
•EU-type examination certificate
•EU declaration of conformity
•Attestation of conformity
•Certificates
•Control drawings
•FMEDA report
•Assessment report
•Additional documents
For more information about Pepperl+Fuchs products with functional safety,
see www.pepperl-fuchs.com/sil.
Note
This document does not substitute the instruction manual.
Note
For full information on the product, refer to the instruction manual and further documentation
on the Internet at www.pepperl-fuchs.com.
Note
For specific device information such as the year of construction, scan the QR code
on the device. As an alternative, enter the serial number in the serial number search
at www.pepperl-fuchs.com.

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Functional Safety KCD2-SCS-(Ex)2(.SP)
Introduction
1.2 Safety Information
Target Group, Personnel
Responsibility for planning, assembly, commissioning, operation, maintenance,
and dismounting lies with the plant operator.
Only appropriately trained and qualified personnel may carry out mounting, installation,
commissioning, operation, maintenance, and dismounting of the product. The personnel
must have read and understood the instruction manual and the further documentation.
Intended Use
The device is only approved for appropriate and intended use. Ignoring these instructions
will void any warranty and absolve the manufacturer from any liability.
The device is developed, manufactured and tested according to the relevant safety standards.
Use the device only
•for the application described
•with specified environmental conditions
•with devices that are suitable for this safety application
Improper Use
Protection of the personnel and the plant is not ensured if the device is not used according
to its intended use.

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Introduction
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1.3 Symbols Used
This document contains symbols for the identification of warning messages and
of informative messages.
Warning Messages
You will find warning messages, whenever dangers may arise from your actions.
It is mandatory that you observe these warning messages for your personal safety and in order
to avoid property damage.
Depending on the risk level, the warning messages are displayed in descending order
as follows:
Informative Symbols
Action
This symbol indicates a paragraph with instructions. You are prompted to perform an action
or a sequence of actions.
Danger!
This symbol indicates an imminent danger.
Non-observance will result in personal injury or death.
Warning!
This symbol indicates a possible fault or danger.
Non-observance may cause personal injury or serious property damage.
Caution!
This symbol indicates a possible fault.
Non-observance could interrupt the device and any connected systems and plants,
or result in their complete failure.
Note
This symbol brings important information to your attention.

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Functional Safety KCD2-SCS-(Ex)2(.SP)
Product Description
2 Product Description
2.1 Function
KCD2-SCS-2(.SP)
This signal conditioner provides galvanic isolation between field circuits and control circuits.
Each device channel works as a transmitter power supply or a current driver.
The device transfers data by using a current signal.
The device supports a bi-directional communication for SMART devices that use current
modulation to transmit data and voltage modulation to receive data.
For current driver operation, an open field circuit presents a high impedance to the control side
to allow lead breakage to be monitored by control systems.
The device is mounted on a 35 mm DIN mounting rail according to EN 60715.
SP Version
The devices are available with screw terminals or spring terminals.
The type code of the versions of the devices with spring terminals has the extension .SP.
KCD2-SCS-Ex2(.SP)
This isolated barrier is used for intrinsic safety applications.
Each device channel works as a transmitter power supply or a current driver.
The device transfers data by using a current signal.
The device supports a bi-directional communication for SMART devices that use current
modulation to transmit data and voltage modulation to receive data.
For current driver operation, an open field circuit presents a high impedance to the control side
to allow lead breakage to be monitored by control systems.
The device is mounted on a 35 mm DIN mounting rail according to EN 60715.
SP Version
The devices are available with screw terminals or spring terminals.
The type code of the versions of the devices with spring terminals has the extension .SP.
2.2 Interfaces
The device has the following interfaces.
•Safety relevant interfaces: input I, input II, output I, output II
•Non-safety relevant interfaces: none
The HART communication is not relevant for functional safety.
Note
For corresponding connections see datasheet.

Functional Safety KCD2-SCS-(Ex)2(.SP)
Product Description
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2.3 Marking
2.4 Standards and Directives for Functional Safety
Device specific standards and directives
System-specific standards and directives
Pepperl+Fuchs Group
Lilienthalstraße 200, 68307 Mannheim, Germany
Internet: www.pepperl-fuchs.com
KCD2-SCS-2, KCD2-SCS-2.SP,
KCD2-SCS-Ex2, KCD2-SCS-Ex2.SP Up to SIL 2
Functional safety IEC/EN 61508, part 1 –7, edition 2010:
Functional safety of electrical/electronic/programmable electronic
safety-related systems (manufacturer)
Functional safety IEC 61511-1:2016+COR1:2016+A1:2017
EN 61511-1:2017+A1:2017
Functional safety –Safety instrumented systems for the process
industry sector (user)

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Functional Safety KCD2-SCS-(Ex)2(.SP)
Planning
3 Planning
3.1 System Structure
3.1.1 Low Demand Mode of Operation
If there are two control loops, one for the standard operation and another one for the functional
safety, then usually the demand rate for the safety loop is assumed to be less than once per
year.
The relevant safety parameters to be verified are:
•the PFDavg value (average Probability of dangerous Failure on Demand) and the T1
value (proof test interval that has a direct impact on the PFDavg value)
•the SFF value (Safe Failure Fraction)
•the HFT architecture (Hardware Fault Tolerance)
3.1.2 High Demand or Continuous Mode of Operation
If there is only one safety loop, which combines the standard operation and safety-related
operation, then usually the demand rate for this safety loop is assumed to be higher than once
per year.
The relevant safety parameters to be verified are:
•the PFH value (Probability of dangerous Failure per Hour)
•Fault reaction time of the safety system
•the SFF value (Safe Failure Fraction)
•the HFT architecture (Hardware Fault Tolerance)
3.1.3 Safe Failure Fraction
The safe failure fraction describes the ratio of all safe failures and dangerous detected failures
to the total failure rate.
SFF = (s + dd) / (s + dd + du)
A safe failure fraction as defined in IEC/EN 61508 is only relevant for elements or (sub)systems
in a complete safety loop. The device under consideration is always part of a safety loop but is
not regarded as a complete element or subsystem.
For calculating the SIL of a safety loop it is necessary to evaluate the safe failure fraction of the
elements and subsystems, but not of a single device.
Nevertheless the SFF of the device is given in this document for reference.

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Planning
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3.2 Assumptions
The following assumptions have been made during the FMEDA:
•Failure rate based on the Siemens standard SN 29500.
•Failure rates are constant, wear is not considered.
•External power supply failure rates are not included.
•The safety-related device is considered to be of type A device with a hardware
fault tolerance of 0.
•The device will be used under average industrial ambient conditions comparable
to the classification stationary mounted according to MIL-HDBK-217F.
Alternatively, operating stress conditions typical of an industrial field environment similar
to IEC/EN 60654-1 Class C with an average temperature over a long period of time
of 40 ºC may be assumed. For a higher average temperature of 60 ºC, the failure rates
must be multiplied by a factor of 2.5 based on experience. A similar factor must be used
if frequent temperature fluctuations are expected.
•Only one input and one output are part of the safety function.
•The application program in the programmable logic controller (PLC) is configured
to detect the following line faults:
•Lead breakage or lead short circuit for analog input
•Lead breakage for analog output
•If you are using the HART communication, observe that the HART signal superimposes
an analog signal on the signal line that can influence the measured value.
Verify that all devices on the signal line are HART compatible when activating
HART communication in one of the devices.

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Functional Safety KCD2-SCS-(Ex)2(.SP)
Planning
3.3 Safety Function and Safe State
Safe State
Device as an Analog Input
The safe state is present when the output current is < 3.6 mA or > 21.5 mA.
Device as an Analog Output
The safe state is present when the output current is < 4 mA.
Safety Function
Device as an Analog Input
The safety function of the device is fulfilled, as long as the output repeats the input current
(4 mA to 20 mA) with a tolerance of 2 %.
A dangerous undetected failure is present if the tolerance limits for the signal transfer
are exceeded and the output current is between 4 mA and 20 mA.
The safety instrumented system (SIS) must ensure suitable reaction when the output current
of the device is < 3.6 mA or > 21.5 mA.
Device as an Analog Output
The safety function of the device is fulfilled, as long as the output repeats the input current
(4 mA to 20 mA) with a tolerance of 2 %.
A dangerous undetected failure is present if the tolerance limits for the signal transfer
are exceeded and the output current is between 4 mA and 20 mA.
Switch settings
Reaction Times
The safety reaction time is the maximum time required from the occurrence of the fault
to the reaction of the outputs in normal operation without faults.
The combined fault detection and fault reaction time is the time in which the device outputs
react to an occurred fault, see chapter 3.4.
Function Switch
Channel 1 Channel 2
Field side Control side S1 S2 S3 S4
Analog input Current source I II I II
Analog input Current sink II I II I
Analog output II I II I
Table 3.1
Note
See corresponding datasheets for further information.

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Planning
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3.4 Characteristic Safety Values
Device as an Analog Input in 1oo1 Structure
Parameters Characteristic values
Assessment type and
documentation Full assessment
Device type A
Mode of operation Low demand mode or high demand mode
HFT 0
SIL 1
1The statement for the SIL rating is based on SFF, HFT and the assumption that this device typically uses 10 % of the failure budget
for the safety loop.
2
SC 3
Safety function Control side output value of < 3.6 mA or > 21.5 mA
s0 FIT
dd 151 FIT
du 32.5 FIT
FH 2
2FH (fail high) denotes failures that lead to outputs above 21.5 mA.
FL (fail low) denotes failures that lead to outputs below 3.6 mA.
These failures were added to form the dd. If this assumption is not correct for your application distribute them as required.
5.5 FIT
FL 2145 FIT
total (safety function) 183 FIT
not part 134 FIT
SFF 82.24 %
PTC 100 %
MTBF 3
3acc. to SN29500. This value includes failures which are not part of the safety function/MTTR = 8 h.
233 years
PFH 3.25 x 10-8 1/h
PFDavg for T1 = 1 year 1.42 x 10-4
PFDavg for T1 = 2 years 2.85 x 10-4
PFDavg for T1 = 5 years 7.12 x 10-4
Reaction time 4
4Time between fault detection and fault reaction
<1s
Table 3.2

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Functional Safety KCD2-SCS-(Ex)2(.SP)
Planning
Device as an Analog Output in 1oo1 Structure
The characteristic safety values like PFD, PFH, SFF, HFT and T1 are taken
from the FMEDA report. Observe that PFD and T1 are related to each other.
The function of the devices has to be checked within the proof test interval (T1).
Parameter Characteristic values
Assessment type and
documentation Full assessment
Device type A
Mode of operation Low demand mode or high demand mode
HFT 0
SIL 1
1The statement for the SIL rating is based on SFF, HFT and the assumption that this device typically uses 10 % of the failure budget
for the safety loop.
2
SC 3
Safety function Control side output value of < 4.0 mA
s0 FIT
dd 150 FIT
du 39.2 FIT
total (safety function) 189 FIT
not part 119 FIT
SFF 79,28 %
PTC 100 %
MTBF 2
2acc. to SN29500. This value includes failures which are not part of the safety function/MTTR = 8 h.
233 years
PFH 3.92 x 10-8 1/h
PFDavg for T1 = 1 year 1.72 x 10-4
PFDavg for T1 = 2 years 3.43 x 10-4
PFDavg for T1 = 5 years 8.58 x 10-4
Reaction time 3
3Time between fault detection and fault reaction
<1s
Table 3.3
Note
The characteristic values apply to all modes of operation that can be set on the device.

Functional Safety KCD2-SCS-(Ex)2(.SP)
Planning
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3.5 Useful Lifetime
Although a constant failure rate is assumed by the probabilistic estimation this only applies
provided that the useful lifetime of components is not exceeded. Beyond this useful lifetime,
the result of the probabilistic estimation is meaningless as the probability of failure significantly
increases with time. The useful lifetime is highly dependent on the component itself and
its operating conditions – temperature in particular. For example, electrolytic capacitors can
be very sensitive to the operating temperature.
This assumption of a constant failure rate is based on the bathtub curve, which shows
the typical behavior for electronic components.
Therefore it is obvious that failure calculation is only valid for components that have
this constant domain and that the validity of the calculation is limited to the useful lifetime
of each component.
It is assumed that early failures are detected to a huge percentage during the installation
and therefore the assumption of a constant failure rate during the useful lifetime is valid.
However, according to IEC/EN 61508-2, a useful lifetime, based on general experience,
should be assumed. Experience has shown that the useful lifetime often lies within a range
period of about 8 to 12 years.
As noted in DIN EN 61508-2:2011 note N3, appropriate measures taken by the manufacturer
and plant operator can extend the useful lifetime.
Our experience has shown that the useful lifetime of a Pepperl+Fuchs product can be higher
if the ambient conditions support a long life time, for example if the ambient temperature
is significantly below the maximum ambient temperature.
Please note that the useful lifetime refers to the (constant) failure rate of the device.
The effective life time can deviate from this.
The estimated useful lifetime is greater than the warranty period prescribed by law
or the manufacturer's guarantee period. However, this does not result in an extension
of the warranty or guarantee services. Failure to reach the estimated useful lifetime
is not a material defect.

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Functional Safety KCD2-SCS-(Ex)2(.SP)
Mounting and Installation
4 Mounting and Installation
Mounting and Installing the Device
1. Observe the safety instructions in the instruction manual.
2. Observe the information in the manual.
3. Observe the requirements for the safety loop.
4. Connect the device only to devices that are suitable for this safety application.
5. Check the safety function to ensure the expected output behavior.
4.1 Configuration
Configuring the Device
The device is configured via DIP switches. The DIP switches are on the front of the device.
1. De-energize the device before configuring the device.
2. Open the cover.
3. Configure the device for the required safety function via the DIP switches, see chapter 3.3.
4. Close the cover.
5. Secure the DIP switches to prevent unintentional adjustments.
6. Connect the device again.
Note
See corresponding datasheets for further information.

Functional Safety KCD2-SCS-(Ex)2(.SP)
Operation
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5 Operation
Operating the device
1. Observe the safety instructions in the instruction manual.
2. Observe the information in the manual.
3. Use the device only with devices that are suitable for this safety application.
4. Correct any occurring safe failures within 8 hours. Take measures to maintain the safety
function while the device is being repaired.
5.1 Proof Test
This section describes a possible proof test procedure. The user is not obliged to use
this proposal. The user may consider different concepts with an individual determination
of the respective effectiveness, e. g. concepts according to NA106:2018.
According to IEC/EN 61508-2 a recurring proof test shall be undertaken to reveal potential
dangerous failures that are not detected otherwise.
Check the function of the subsystem at periodic intervals depending on the applied PFDavg
in accordance with the characteristic safety values. See chapter 3.4.
It is under the responsibility of the plant operator to define the type of proof test and the interval
time period.
Conditions
•Digital multimeter with an accuracy better than 0.1 %
Use for the proof test of the intrinsic safety side of the device a special digital multimeter
for intrinsically safe circuits.
If intrinsically safe circuits are operated with non-intrinsically safe circuits,
they must no longer be used as intrinsically safe circuits.
•Power supply set to nominal voltage of 24 V DC
•Process calibrator with current source function with an accuracy better than 20 µA
Danger!
Danger to life from missing safety function
If the safety loop is put out of service, the safety function is no longer guaranteed.
•Do not deactivate the device.
•Do not bypass the safety function.
•Do not repair, modify, or manipulate the device.

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Functional Safety KCD2-SCS-(Ex)2(.SP)
Operation
Proof Test Procedure
1. Put out of service the entire safety loop. Protect the application by means of other measures.
2. Prepare a test set-up, see figures below.
3. Test the devices. Verify the current values as given in the tables below.
4. Set back the device to the original settings for the application after the test.
Device as an Analog Input
Figure 5.1 Proof test set-up for KCD2-SCS-(Ex)2(.SP) as an analog input
Usage in Zone 0, 1, 2/Div. 1, 2 only for KCD2-SCS-Ex2(.SP).
Step
No.
Set input value (mA) Set output value Rload () Mandatory measuring points
(safety-relevant) output value
(mA)
1 20.00 250 20.00 ± 0.40
2 12.00 250 12.00 ± 0.40
3 4.00 250 4.00 ± 0.40
4 23.00 250 23.00 ± 0.40
5 0 250 < 0.30
6 12.00 > 100000 < 0.30
7 12.00 Restored as step 2
Table 5.1 Steps to be performed for the proof test
KCD2-SCS-Ex2(.SP)
Zone 0, 1, 2
Div. 1, 2
Zone 2
Div. 2
I supply
14+
15-
1+
2-
5-
6+
3+
4-
7-
8+
mA
mA
I
II
Multimeter
(mA )
Multimeter
(mA )
24 V DC
Power
supply
Supply
4 mA to 20 mA
4 mA to 20 mA
4 mA to 20 mA
4 mA to 20 mA

Functional Safety KCD2-SCS-(Ex)2(.SP)
Operation
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Device as an Analog Output
Figure 5.2 Proof test set-up for KCD2-SCS-(Ex)2(.SP) as an analog output
Usage in Zone 0, 1, 2/Div. 1, 2 only for KCD2-SCS-Ex2(.SP).
Step
No.
Set input value (mA) Set output value Rload () Mandatory measuring points
(safety-relevant) output value
(mA)
1 20.00 500 20.00 ± 0.40
2 12.00 500 12.00 ± 0.40
3 4.00 500 4.00 ± 0.40
4 23.00 500 23.00 ± 0.40
5 0 500 < 0.30
6 12.00 > 100000 < 0.30
7 12.00 Restored as step 2
Table 5.2
KCD2-SCS-Ex2(.SP)
Zone 0, 1, 2
Div. 1, 2
Zone 2
Div. 2
Multimeter
(mA )
I supply
14+
15-
mA
mA
I
II
Multimeter
(mA )
1+
2-
5-
6+
3+
4-
7-
8+
24 V DC
Power
supply
Supply
4 mA to 20 mA
4 mA to 20 mA
4 mA to 20 mA
4 mA to 20 mA

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Functional Safety KCD2-SCS-(Ex)2(.SP)
Maintenance and Repair
6 Maintenance and Repair
Maintaining, Repairing or Replacing the Device
In case of maintenance, repair or replacement of the device, proceed as follows:
1. Implement appropriate maintenance procedures for regular maintenance of the safety loop.
2. While the device is maintained, repaired or replaced, the safety function does not work.
Take appropriate measures to protect personnel and equipment while the safety function
is not available.
Secure the application against accidental restart.
3. Do not repair a defective device. A defective device must only be repaired by the manufacturer.
4. If there is a defect, always replace the device with an original device.
Reporting Device Failure
If you use the device in a safety loop according to IEC/EN 61508, it is required to inform
the device manufacturer about possible systematic failures.
Report all failures in the safety function that are due to functional limitations or a loss
of device function – especially in the case of possible dangerous failures.
In these cases, contact your local sales partner or the Pepperl+Fuchs technical sales support
(service line).
It is not necessary to report failures in the safety function that are due to external influences
or damage.
Danger!
Danger to life from missing safety function
Changes to the device or a defect of the device can lead to device malfunction.
The function of the device and the safety function is no longer guaranteed.
Do not repair, modify, or manipulate the device.