Siemens 6ES7431-1KF20-0AB0
SM 431 analog input, 8 AI, 14 bit, 0.42 ms for all channels
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Siemens SIMATIC S7-400 SM 431 analog input module: 8 isolated inputs for voltage, current or resistance, 14-bit resolution, 52 µs per channel, 0.42 ms for all channels.
- Manufacturer
- Siemens
- Manufacturer part no.
- 6ES7431-1KF20-0AB0
- Product family
- SIMATIC S7-400 PLC CPUs, I/O and Function Modules
- Type
- Analog input module
- Category
- PLCs and I/O › Analogue I/O modules
- Lifecycle
- Discontinued
- OEM successor
- Not stated
- Technical datasheet
- Data sheet
Technical specifications
- Manufacturer
- Siemens
- Manufacturer part no.
- 6ES7431-1KF20-0AB0
- Type
- Analog input module
- Application
- Analog input module
- Used with
- SIMATIC S7-400 rack
- Load voltage L+ / Rated value (DC)
- 24 V; Only required for supplying 2-wire transmitters
- Load voltage L+ / Reverse polarity protection
- Yes
- Input current / from load voltage L+ (without load), max.
- 200 mA; for 8 connected, fully controlled 2-wire transmitters
- Input current / from backplane bus 5 V DC, max.
- 1 000 mA
- Power loss, typ.
- 4.9 W
- Number of analog inputs
- 8
- Number of analog inputs / For voltage/current measurement
- 8
- Number of analog inputs / For resistance measurement
- 4
- Analog inputs / permissible input voltage for voltage input (destruction limit), max.
- 18 V; 18 V continuous, 75 V for 1 ms (mark to space ratio 1:20)
- Analog inputs / permissible input current for current input (destruction limit), max.
- 40 mA; Permanent
- Analog inputs / Constant measurement current for resistance-type transmitter, typ.
- 1.67 mA
- Input ranges / Voltage
- Yes
- Input ranges / Current
- Yes
- Input ranges / Thermocouple
- No
- Input ranges / Resistance thermometer
- No
- Input ranges / Resistance
- Yes
- Input ranges (rated values), voltages / 1 V to 5 V
- Yes
- Input ranges (rated values), voltages / 1 V to 5 V / Input resistance (1 V to 5 V)
- 10 MΩ
- Input ranges (rated values), voltages / -1 V to +1 V
- Yes
- Input ranges (rated values), voltages / -1 V to +1 V / Input resistance (-1 V to +1 V)
- 10 MΩ
- Input ranges (rated values), voltages / -10 V to +10 V
- Yes
- Input ranges (rated values), voltages / -10 V to +10 V / Input resistance (-10 V to +10 V)
- 100 kΩ
- Input ranges (rated values), currents / -20 mA to +20 mA
- Yes
- Input ranges (rated values), currents / -20 mA to +20 mA / Input resistance (-20 mA to +20 mA)
- 50 Ω
- Input ranges (rated values), currents / 4 mA to 20 mA
- Yes
Show all 62 specificationsShow fewer
- Input ranges (rated values), currents / 4 mA to 20 mA / Input resistance (4 mA to 20 mA)
- 50 kΩ
- Input ranges (rated values), resistors / 0 to 600 ohms
- Yes
- Cable length / shielded, max.
- 200 m
- Integration and conversion time/resolution per channel / Resolution with overrange (bit including sign), max.
- 14 bit; 14 / 14 / 14
- Integration and conversion time/resolution per channel / Integration time, parameterizable
- Yes
- Integration and conversion time/resolution per channel / Basic conversion time (ms)
- 52 µs
- Integration and conversion time/resolution per channel / Interference voltage suppression for interference frequency f1 in Hz
- none / 400 / 60 / 50 Hz
- Integration and conversion time/resolution per channel / Time constant of the input filter
- 15 µs
- Integration and conversion time/resolution per channel / Basic execution time of the module (all channels released)
- 0.42 ms
- Connection of signal encoders / for voltage measurement
- Yes; possible
- Connection of signal encoders / for current measurement as 2-wire transducer
- Yes
- Connection of signal encoders / for current measurement as 4-wire transducer
- Yes
- Connection of signal encoders / for resistance measurement with two-wire connection
- Yes; Line resistances are also measured
- Connection of signal encoders / for resistance measurement with three-wire connection
- Yes; Line resistances are also measured
- Connection of signal encoders / for resistance measurement with four-wire connection
- Yes
- Errors/accuracies / Temperature error (relative to input range), (+/-)
- 0.03 %/K
- Operational error limit in overall temperature range / Voltage, relative to input range, (+/-)
- 0.7 %; ±0.7 % at ±1 V; ±0.9 % at ±10 V, 1 to 5 V
- Operational error limit in overall temperature range / Current, relative to input range, (+/-)
- 0.8 %; at ±20 mA, 4 to 20 mA
- Operational error limit in overall temperature range / Resistance, relative to input range, (+/-)
- 1 %
- Basic error limit (operational limit at 25 °C) / Voltage, relative to input range, (+/-)
- 0.6 %; 0.6 % at ±1 V; 0.75 % at ±10 V, 1 to 5 V
- Basic error limit (operational limit at 25 °C) / Current, relative to input range, (+/-)
- 0.7 %; at ±20 mA, 4 to 20 mA
- Basic error limit (operational limit at 25 °C) / Resistance, relative to input range, (+/-)
- 0.7 %; 0 to 600 ohms
- Interrupts/diagnostics/status information / Diagnostics function
- No
- Potential separation analog inputs / Potential separation analog inputs
- Yes; internal/external
- Potential separation analog inputs / between the channels
- No
- Potential separation analog inputs / between the channels and backplane bus
- Yes
- Potential separation analog inputs / Between the channels and load voltage L+
- Yes
- Isolation tested with
- 2 120 V DC between bus and analog section; 500 V DC between bus and local ground; 500 V DC between analog part and L+/M; 2 120 V DC between analog part and local ground; 2 120 V DC between L+/M and local ground
- Width
- 25 mm
- Height
- 290 mm
- Depth
- 210 mm
- Weight, approx.
- 500 g
Technical documents (1)
Key features
- 8 inputs for voltage or current, 4 for resistance
- 14-bit resolution, 52 µs conversion per channel
- All 8 channels converted in 0.42 ms
- Ranges: ±1 V, ±10 V, 1 to 5 V, ±20 mA, 4 to 20 mA, 0 to 600 Ω
- Discontinued by Siemens on 1 October 2026
About the Siemens 6ES7431-1KF20-0AB0
The Siemens 6ES7431-1KF20-0AB0 is the fast SM 431: it converts each channel in 52 µs and all 8 in 0.42 ms, where the 6ES7431-1KF00-0AB0 needs 200 ms. It covers the same voltage, current and resistance ranges as the 1KF00, at 14-bit resolution. Siemens's data sheet gives a 15 µs input filter time constant and 4.9 W typical power loss. SiePortal shows its phase-out announced on 1 October 2025 and its product cancellation on 1 October 2026.
What is the 6ES7431-1KF20-0AB0 used for?
It reads fast-changing analog signals into an S7-400 CPU, where a slower module would miss changes.
Lifecycle and successor
Discontinued.
Before you order
What to photograph or confirm so the right unit is quoted.
Check the order number on the module: 1KF20 is the fast version.
Other parts in the Siemens SIMATIC S7-400 family
Listed for reference. They differ from the 6ES7431-1KF20-0AB0 in rating, supply, interface or function and are not interchangeable with it unless Siemens says so. Match the part number on your unit.
| Product | Type | Lifecycle | Qty Available | Price | Action |
|---|---|---|---|---|---|
| Siemens 6ES7422-1BH11-0AA0SM 422 digital output, 16 DO, 24 V DC, 2 A | Digital output module | Discontinued | On Request | On request | View |
| Siemens 6ES7422-7BL00-0AB0SM 422 digital output, 32 DO, 24 V DC, 0.5 A, diagnostics | Digital output module | Discontinued | On Request | On request | View |
| Siemens 6ES7422-1FH00-0AA0SM 422 digital output, 16 DO, 120/230 V AC, 2 A | Digital output module | Discontinued | On Request | On request | View |
| Siemens 6ES7422-1HH00-0AA0SM 422 relay output, 16 DO, 5 A | Digital output module | Discontinued | On Request | On request | View |
| Siemens 6ES7431-1KF00-0AB0SM 431 analog input, 8 AI, 13 bit, U/I/R | Analog input module | Discontinued | On Request | On request | View |
| Siemens 6ES7431-1KF10-0AB0SM 431 analog input, 8 AI, 14 bit, U/I/R/thermocouple/RTD | Analog input module | Discontinued | On Request | On request | View |
| Siemens 6ES7431-7QH00-0AB0SM 431 analog input, 16 AI, 16 bit, universal, diagnostics | Analog input module | Discontinued | On Request | On request | View |
| Siemens 6ES7431-7KF00-0AB0SM 431 analog input, 8 AI, 16 bit, U/I/thermocouple | Analog input module | Discontinued | On Request | On request | View |
| Siemens 6ES7431-7KF10-0AB0SM 431 analog input, 8 AI, 16 bit, resistance thermometers | Analog input module | Discontinued | On Request | On request | View |
| Siemens 6ES7431-0HH00-0AB0SM 431 analog input, 16 AI, 13 bit, non-isolated | Analog input module | Discontinued | On Request | On request | View |
| Siemens 6ES7432-1HF00-0AB0SM 432 analog output, 8 AO, 13 bit, U/I | Analog output module | Discontinued | On Request | On request | View |
| Siemens 6ES7450-1AP01-0AE0FM 450-1 counter module, 2 channels, up to 500 kHz | Counter module | Discontinued | On Request | On request | View |
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