Features:
- Eight channels acquire voltage or current signals.
- Four paths can measure resistance with 2-, 3- or 4-wire circuits.
- Isolation separates the analog section from the S7-400 backplane.
The selected measuring mode determines terminal use and value scaling.
Two-wire transmitters draw power from the external 24 V DC load supply.
Released channels are converted within the documented module cycle.
The Siemens 6ES7431-1KF20-0AB0 S7-400 SM 431 Analog Input Module may still be available for purchase and support from Apter Power beyond End-Of-Life (EOL) by the manufacturer (OEM).
Siemens 6ES7431-1KF20-0AB0 S7-400 SM 431 Analog Input Module Manuals,Datasheets,Link
Important Notice: Other accessories, manuals, cables, calibration data, software, etc. are not included with this equipment unless listed in the above stock item description. All prices are shown in USD.
Assigning each input to the required measurement method
- Voltage input: The selected voltage range defines how the terminal level becomes a digital value.
- Current input: Active or two-wire transmitter circuits follow their documented current wiring.
- Resistance input: Four measurement paths accept the supported resistance connection methods.
- Parameter match: Signal type, range and terminal assignment must agree before values are evaluated.
Feeding two-wire devices without combining every measurement reference
- Load voltage: An external 24 V DC source powers connected two-wire transmitters.
- Current demand: The maximum load-supply current applies with all eight transmitters controlled.
- Passive signals: Other documented input circuits do not use the transmitter feed in the same way.
- Reverse polarity: The load input includes the specified polarity protection.
Separating sensor resistance from lead resistance
- Two-wire circuit: Sensor and lead resistance appear in the same measurement path.
- Three-wire circuit: A matched additional conductor compensates the documented lead contribution.
- Four-wire circuit: Separate force and sense conductors isolate lead drop from the sensor value.
- Channel count: Resistance mode is available on four of the module measurement paths.
Moving analog levels through conversion and backplane isolation
- Input filter: The front-end filter conditions the selected field signal.
- Converter: A released channel is digitized with 14-bit resolution.
- Module cycle: All active channels are processed within the documented update interval.
- Backplane boundary: The resulting values cross the isolated interface to the S7-400 CPU.