P+F Pepperl+Fuchs Signal Isolator KCD2-STC-1

Intelligent Signal Isolator
1-channel signal conditioner, 24V DC power supply (power rail), input for 2-wire SMART isolator and current source, output 4 mA…20 mA or 1 V…5 V, housing width 12.5 mm, height SIL 2 acc. to IEC/EN 61508, housing width: 12.5 mm, number of channels: 1 channel, HART communication, Safety Integrity Level (SIL): SIL 2, rated voltage: 19…30 V DC, field device: 2-wire transmitter, field device [2]: current source, input signal: 4…20 mA limited to approx. 26 mA

Intelligent Signal Isolator KCD2-STC-1
Single-channel signal conditioner
24V DC power supply (power rail)
Input for 2-wire SMART transmitter and current source
Output 4 mA…20 mA or 1 V…5 V
Housing width 12.5 mm
Up to SIL 2 acc. to IEC/EN 61508

Excerpt of technical parameters:
General specifications
Signal type Analog input
Function safety-related parameters
Safety Integrity Level (SIL)
Supply
Connection power rail or terminals 9+, 10-
Rated voltage 19…30 V DC
Ripple ≤10%
Rated current ≤45 mA at 24V and 20 mA source mode output
Power consumption ≤800 mW
Power consumption ≤1.1 W
Input
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-: 20 V / 26 mA
Voltage drop Terminals 3+, 4-: approx. 5 V
Available voltage Terminals 1+, 2-: ≥16 V at 20 mA; ≥17 V at 4 mA
Output
Connection side Control side
Connection terminals 5-, 6+
Terminals 5-, 8+ for HART resistor
Load 0…525 Ω (10.5 Vmax source mode)
Output signal Source mode: 4…20 mA or 1…5 V (internal resistance: 250 Ω, 0.1%)
Sink mode: 4…20 mA, operating voltage 5…30 V
For additional internal or external loads (e.g., terminal +8), voltage drop must be considered, e.g., 250 Ω × 20 mA = 5 V.
Ripple 20 mV RMS

Transmission characteristics
Deviation at 20°C (68°F)
<0.1% of full scale, including non-linearity and hysteresis (source and sink mode 4…20 mA)
≤±0.2%, including non-linearity and hysteresis (source mode 1…5 V)
Ambient temperature and temperature effect; 2 μA/K (-20…70°C (-4…158°F)); <4 μA/K (-40…-20°C (-40…-4°F)) (source and sink mode 4…20 mA)
<0.5 mV/K (-20…70°C (-4…158°F)); <1 mV/K (-40…-20°C (-40…-4°F)) (source mode 1 V)
Frequency range Field side to control side: bandwidth with 0.5 Vpp signal 0…3 kHz (-3 dB)
Control side to field side: bandwidth with 0.5 Vpp signal 0…3 kHz (-3 dB)
Settling time ≤50 ms
Rise/fall time ≤10 ms
Electrical isolation
Input/Output Basic insulation acc. to IEC/EN 61010-1, rated insulation voltage 300 Veff
Input/Power Reinforced insulation acc. to IEC/EN 61010-1, rated insulation voltage 300 Veff
Output/Power Basic insulation acc. to IEC/EN 61010-1, rated insulation voltage 300 Veff
Indication/Setting
Display elements LEDs
Control elements DIP switches
Configuration via DIP switches
Front labeling space
Directive compliance
Electromagnetic compatibility
Directive 2014/30/EU EN 61326-1:2013 (industrial locations)
Integration
Electromagnetic compatibility NE 21:2017
EN 61326-3-2:2018
Protection class IEC 60529:2001
Environmental conditions
Ambient temperature -40…70°C (-40…158°F)
Mechanical specifications
Protection class IP20
Connection Screw terminals
Mass approx. 100 g
Dimensions 12.5 × 124 × 114 mm (0.5 × 4.9 × 4.5 in) (W × H × D), housing type A2
Mounting on 35 mm DIN rail acc. to EN 60715:2001

Brief introduction to the principle of signal conditioners:

Signal conditioning refers to the process of converting the raw output of a load cell into a usable signal. Load cells themselves do not measure or read the electrical signals passing through them. The wires carrying the signal are welded to strain gauges, which are in turn bonded to the cell body. A change in the shape of the load cell alters the shape of the strain gauge through which the current passes, thereby changing its resistance. The result is a change in the output signal of the load cell. Without additional weighing system components to receive and interpret the signal, the load cell itself is not very useful.

For most control systems, it is often necessary to convert input signals into a signal mode acceptable to the system. The function of a signal conditioner is to convert various field signals, such as thermocouples and RTDs, into multiple standard instrument signals (1…5V, 4…20 mA, etc.).
Signal conditioners play a significant role in the precise transmission of signals, signal isolation, and prevention of signal interference.

Signal conditioning functions can be divided into three main categories: 1. Noise reduction 2. Adjusting the signal magnitude 3. Conversion to the desired format.

P+F Pepperl+Fuchs Signal Isolator KCD2-STC-1