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The Pepperl+Fuchs KCD2-STC-Ex1 is a 1-channel intrinsically safe isolated barrier designed to power 2-wire SMART transmitters or interface with 2-wire SMART current sources in hazardous locations. Operating on a 24 V DC power supply via terminals or the Power Rail system, it transfers the analog 4 mA to 20 mA field signal across galvanic isolation to the safe area. The device maintains bi-directional digital signal transmission for protocols such as HART and BRAIN, permitting continuous remote parameterization and diagnostic communication with field instrumentation.
Featuring a compact 12.5 mm housing, the KCD2-STC-Ex1 incorporates selectable output modes—current source, current sink, or voltage output—configurable through onboard DIP switches. An internal 250 Ω resistor is accessible via specific terminal connections to establish necessary HART communication loop impedance when control side resistance is insufficient. Additionally, integrated test sockets within the terminals enable direct connection of HART communicators without disrupting loop wiring.
The module is certified up to SIL 2 (SC 3) per IEC/EN 61508 for functional safety applications. It provides galvanic isolation between input, output, and power circuits to ensure signal integrity and safe operations across Zone 0, Zone 1, Zone 2, and Division 1/2 environments.
| Parameter | Specification |
|---|---|
| Manufacturer | Pepperl+Fuchs |
| Model | KCD2-STC-Ex1 |
| Signal Type | Analog input |
| Channels | 1-channel |
| Functional Safety | SIL 2 / Systematic Capability SC 3 acc. to IEC/EN 61508 |
| Parameter | Specification |
|---|---|
| Connection | Power Rail or terminals 9+, 10- |
| Rated Voltage Ur | 19 ... 30 V DC |
| Ripple | <= 10 % |
| Rated Current Ir | <= 45 mA at 24 V and 20 mA source mode output |
| Power Dissipation | <= 800 mW |
| Power Consumption | <= 1.1 W |
| Parameter | Specification |
|---|---|
| Connection Side | Field side |
| Connection Terminals | 1+, 2- ; 3+, 4- |
| Input Signal | 4 ... 20 mA limited to approx. 26 mA |
| Open Circuit Voltage / Short-Circuit Current | Terminals 1+, 2-: 22 V / 26 mA |
| Voltage Drop | Terminals 3+, 4-: approx. 5 V |
| Available Voltage | Terminals 1+, 2-: >= 15 V at 20 mA ; >= 18 V at 4 mA |
| Parameter | Specification |
|---|---|
| Connection Side | Control side |
| Connection Terminals | Terminals 5-, 6+; terminals 5-, 8+ for HART resistor |
| Source Mode Load | 0 ... 350 Ω |
| Output Signal Source Mode | 4 ... 20 mA or 1 ... 5 V (internal resistor: 250 Ω, 0.1 %) |
| Output Signal Sink Mode | 4 ... 20 mA, operating voltage 10 ... 30 V |
| Ripple | 20 mV rms |
| Parameter | Specification |
|---|---|
| Deviation at 20 degC | < 0.1 % of full scale incl. non-linearity and hysteresis (source/sink 4 ... 20 mA) |
| Deviation at 20 degC (Voltage) | <= +- 0.2 % incl. non-linearity and hysteresis (source mode 1 ... 5 V) |
| Ambient Temperature Influence (Current) | < 2 uA/K (-20 ... 70 degC); < 4 uA/K (-40 ... -20 degC) |
| Ambient Temperature Influence (Voltage) | < 0.5 mV/K (-20 ... 70 degC); < 1 mV/K (-40 ... -20 degC) |
| Frequency Range | Field side into control side: 0 ... 3 kHz (-3 dB, 0.5 Vpp signal) |
| Frequency Range (Reverse) | Control side into field side: 0 ... 3 kHz (-3 dB, 0.5 Vpp signal) |
| Settling Time | <= 50 ms |
| Rise Time / Fall Time | <= 10 ms |
| Parameter | Specification |
|---|---|
| Input / Output | Basic insulation acc. to IEC/EN 61010-1, rated insulation voltage 300 Veff |
| Input / Power Supply | Reinforced insulation acc. to IEC/EN 61010-1, rated insulation voltage 300 Veff |
| Output / Power Supply | Basic insulation acc. to IEC/EN 61010-1, rated insulation voltage 300 Veff |
| Ex Safety Isolation (Input/Output) | Safe electrical isolation acc. to IEC/EN 60079-11, voltage peak value 375 V |
| Ex Safety Isolation (Input/Power) | Safe electrical isolation acc. to IEC/EN 60079-11, voltage peak value 375 V |
| Parameter | Specification |
|---|---|
| Degree of Protection | IP20 |
| Connection Type | Screw terminals |
| Mass | Approx. 100 g |
| Dimensions (W x H x D) | 12.5 x 119 x 114 mm (0.5 x 4.7 x 4.5 inch), housing type A2 |
| Mounting | 35 mm DIN mounting rail acc. to EN 60715:2001 |
| Ambient Temperature | -40 ... 70 degC (-40 ... 158 degF) |
| Terminal | Function |
|---|---|
| 1+ | Field Input: 2-wire Transmitter (+) |
| 2- | Field Input: 2-wire Transmitter (-) |
| 3+ | Field Input: Current Source (+) |
| 4- | Field Input: Current Source (-) |
| 5- | Control Output (-) |
| 6+ | Control Output (+) |
| 8+ | Control Output (+) with internal 250 Ω HART resistor |
| 9+ | Safe Area Power Supply 24 V DC (+) |
| 10- | Safe Area Power Supply 24 V DC (-) |
The output operational mode is set via four DIP switches (S1, S2, S3, S4) located on the side of the housing:
| Mode of Operation | S1 | S2 | S3 | S4 |
|---|---|---|---|---|
| Current source output 4 ... 20 mA (Default) | II | II | I | II |
| Voltage source output 1 ... 5 V | II | II | I | I |
| Current sink output 4 ... 20 mA | II | I | II | II |
Note: Change DIP switch positions only when no explosive atmosphere is present.
| Certification / Standard | Details |
|---|---|
| ATEX (Intrinsic Safety) | CESI 06 ATEX 021 X: II (1)G [Ex ia Ga] IIC, II (1)D [Ex ia Da] IIIC, I (M1) [Ex ia Ma] I |
| ATEX (Zone 2) | CESI 19 ATEX 021 X: II 3G Ex ec IIC T4 Gc |
| IECEx | IECEx CES 06.0001X: [Ex ia Ga] IIC, [Ex ia Da] IIIC, [Ex ia Ma] I, Ex ec IIC T4 Gc |
| North America | FM 18 CA 0116 X, FM 19 US 0117 X, cULus E106378: Class I, Div 2, Groups A-D T4; Associated apparatus for Class I, II, III Div 1 |
| CCC | 2020322316001218: Ex ec [ia Ga] IIC T4 Gc, [Ex ia Da] IIIC |
| EMC Directive | 2014/30/EU, EN 61326-1:2013, NE 21:2017, EN 61326-3-2:2018 |
| ATEX Directive | 2014/34/EU, EN IEC 60079-0, EN IEC 60079-11, EN IEC 60079-7 |
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The Pepperl+Fuchs KCD2-STC-Ex1 is a 1-channel intrinsically safe isolated barrier designed to power 2-wire SMART transmitters or interface with 2-wire SMART current sources in hazardous locations. Operating on a 24 V DC power supply via terminals or the Power Rail system, it transfers the analog 4 mA to 20 mA field signal across galvanic isolation to the safe area. The device maintains bi-directional digital signal transmission for protocols such as HART and BRAIN, permitting continuous remote parameterization and diagnostic communication with field instrumentation.
Featuring a compact 12.5 mm housing, the KCD2-STC-Ex1 incorporates selectable output modes—current source, current sink, or voltage output—configurable through onboard DIP switches. An internal 250 Ω resistor is accessible via specific terminal connections to establish necessary HART communication loop impedance when control side resistance is insufficient. Additionally, integrated test sockets within the terminals enable direct connection of HART communicators without disrupting loop wiring.
The module is certified up to SIL 2 (SC 3) per IEC/EN 61508 for functional safety applications. It provides galvanic isolation between input, output, and power circuits to ensure signal integrity and safe operations across Zone 0, Zone 1, Zone 2, and Division 1/2 environments.
| Parameter | Specification |
|---|---|
| Manufacturer | Pepperl+Fuchs |
| Model | KCD2-STC-Ex1 |
| Signal Type | Analog input |
| Channels | 1-channel |
| Functional Safety | SIL 2 / Systematic Capability SC 3 acc. to IEC/EN 61508 |
| Parameter | Specification |
|---|---|
| Connection | Power Rail or terminals 9+, 10- |
| Rated Voltage Ur | 19 ... 30 V DC |
| Ripple | <= 10 % |
| Rated Current Ir | <= 45 mA at 24 V and 20 mA source mode output |
| Power Dissipation | <= 800 mW |
| Power Consumption | <= 1.1 W |
| Parameter | Specification |
|---|---|
| Connection Side | Field side |
| Connection Terminals | 1+, 2- ; 3+, 4- |
| Input Signal | 4 ... 20 mA limited to approx. 26 mA |
| Open Circuit Voltage / Short-Circuit Current | Terminals 1+, 2-: 22 V / 26 mA |
| Voltage Drop | Terminals 3+, 4-: approx. 5 V |
| Available Voltage | Terminals 1+, 2-: >= 15 V at 20 mA ; >= 18 V at 4 mA |
| Parameter | Specification |
|---|---|
| Connection Side | Control side |
| Connection Terminals | Terminals 5-, 6+; terminals 5-, 8+ for HART resistor |
| Source Mode Load | 0 ... 350 Ω |
| Output Signal Source Mode | 4 ... 20 mA or 1 ... 5 V (internal resistor: 250 Ω, 0.1 %) |
| Output Signal Sink Mode | 4 ... 20 mA, operating voltage 10 ... 30 V |
| Ripple | 20 mV rms |
| Parameter | Specification |
|---|---|
| Deviation at 20 degC | < 0.1 % of full scale incl. non-linearity and hysteresis (source/sink 4 ... 20 mA) |
| Deviation at 20 degC (Voltage) | <= +- 0.2 % incl. non-linearity and hysteresis (source mode 1 ... 5 V) |
| Ambient Temperature Influence (Current) | < 2 uA/K (-20 ... 70 degC); < 4 uA/K (-40 ... -20 degC) |
| Ambient Temperature Influence (Voltage) | < 0.5 mV/K (-20 ... 70 degC); < 1 mV/K (-40 ... -20 degC) |
| Frequency Range | Field side into control side: 0 ... 3 kHz (-3 dB, 0.5 Vpp signal) |
| Frequency Range (Reverse) | Control side into field side: 0 ... 3 kHz (-3 dB, 0.5 Vpp signal) |
| Settling Time | <= 50 ms |
| Rise Time / Fall Time | <= 10 ms |
| Parameter | Specification |
|---|---|
| Input / Output | Basic insulation acc. to IEC/EN 61010-1, rated insulation voltage 300 Veff |
| Input / Power Supply | Reinforced insulation acc. to IEC/EN 61010-1, rated insulation voltage 300 Veff |
| Output / Power Supply | Basic insulation acc. to IEC/EN 61010-1, rated insulation voltage 300 Veff |
| Ex Safety Isolation (Input/Output) | Safe electrical isolation acc. to IEC/EN 60079-11, voltage peak value 375 V |
| Ex Safety Isolation (Input/Power) | Safe electrical isolation acc. to IEC/EN 60079-11, voltage peak value 375 V |
| Parameter | Specification |
|---|---|
| Degree of Protection | IP20 |
| Connection Type | Screw terminals |
| Mass | Approx. 100 g |
| Dimensions (W x H x D) | 12.5 x 119 x 114 mm (0.5 x 4.7 x 4.5 inch), housing type A2 |
| Mounting | 35 mm DIN mounting rail acc. to EN 60715:2001 |
| Ambient Temperature | -40 ... 70 degC (-40 ... 158 degF) |
| Terminal | Function |
|---|---|
| 1+ | Field Input: 2-wire Transmitter (+) |
| 2- | Field Input: 2-wire Transmitter (-) |
| 3+ | Field Input: Current Source (+) |
| 4- | Field Input: Current Source (-) |
| 5- | Control Output (-) |
| 6+ | Control Output (+) |
| 8+ | Control Output (+) with internal 250 Ω HART resistor |
| 9+ | Safe Area Power Supply 24 V DC (+) |
| 10- | Safe Area Power Supply 24 V DC (-) |
The output operational mode is set via four DIP switches (S1, S2, S3, S4) located on the side of the housing:
| Mode of Operation | S1 | S2 | S3 | S4 |
|---|---|---|---|---|
| Current source output 4 ... 20 mA (Default) | II | II | I | II |
| Voltage source output 1 ... 5 V | II | II | I | I |
| Current sink output 4 ... 20 mA | II | I | II | II |
Note: Change DIP switch positions only when no explosive atmosphere is present.
| Certification / Standard | Details |
|---|---|
| ATEX (Intrinsic Safety) | CESI 06 ATEX 021 X: II (1)G [Ex ia Ga] IIC, II (1)D [Ex ia Da] IIIC, I (M1) [Ex ia Ma] I |
| ATEX (Zone 2) | CESI 19 ATEX 021 X: II 3G Ex ec IIC T4 Gc |
| IECEx | IECEx CES 06.0001X: [Ex ia Ga] IIC, [Ex ia Da] IIIC, [Ex ia Ma] I, Ex ec IIC T4 Gc |
| North America | FM 18 CA 0116 X, FM 19 US 0117 X, cULus E106378: Class I, Div 2, Groups A-D T4; Associated apparatus for Class I, II, III Div 1 |
| CCC | 2020322316001218: Ex ec [ia Ga] IIC T4 Gc, [Ex ia Da] IIIC |
| EMC Directive | 2014/30/EU, EN 61326-1:2013, NE 21:2017, EN 61326-3-2:2018 |
| ATEX Directive | 2014/34/EU, EN IEC 60079-0, EN IEC 60079-11, EN IEC 60079-7 |
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Returns & Warranty
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| Country of origin |
Germany
|