| General information |
| Product type designation | SM 1231, AI 8x 14 bit |
| Supply voltage |
| Rated value (DC) | 24 V |
| permissible range, lower limit (DC) | 20.4 V |
| permissible range, upper limit (DC) | 28.8 V |
| Input current |
| Current consumption, typ. | 45 mA |
| from backplane bus 5 V DC, typ. | 75 mA |
| Power loss |
| Power loss, typ. | 2.5 W |
| Analog inputs |
| Number of analog inputs | 8; Current or voltage differential inputs |
| permissible input voltage for voltage input (destruction limit), max. | 35 V |
| permissible input current for current input (destruction limit), max. | 40 mA |
| Cycle time (all channels) max. | 1.25 ms; at 400 Hz rejection |
| Input ranges |
| ● Voltage | Yes; ±10V, ±5V, ±2.5V |
| ● Current | Yes; 4 to 20 mA, 0 to 20 mA |
| ● Thermocouple | No |
| ● Resistance thermometer | No |
| ● Resistance | No |
| Input ranges (rated values), voltages |
| ● -10 V to +10 V | Yes |
| — Input resistance (-10 V to +10 V) | ≥1 MOhm |
| ● -2.5 V to +2.5 V | Yes |
| — Input resistance (-2.5 V to +2.5 V) | ≥1 MOhm |
| ● -5 V to +5 V | Yes |
| — Input resistance (-5 V to +5 V) | ≥1 MOhm |
| Input ranges (rated values), currents |
| ● 0 to 20 mA | Yes |
| — Input resistance (0 to 20 mA) | < 290 Ω, > 270 Ω |
| ● 4 mA to 20 mA | Yes |
| — Input resistance (4 mA to 20 mA) | < 290 Ω, > 270 Ω |
| Cable length |
| ● shielded, max. | 100 m; shielded, twisted pair |
| Analog value generation for the inputs |
| Measurement principle | successive approximation |
| Integration and conversion time/resolution per channel |
| ● Resolution with overrange (bit including sign), max. | 13 bit; + sign |
| ● Integration time, parameterizable | Yes |
| ● Interference voltage suppression for interference frequency f1 in Hz | 40 dB, DC to 60 Hz |
| Smoothing of measured values |
| ● parameterizable | Yes |
| ● Step: None | Yes |
| ● Step: low | Yes |
| ● Step: Medium | Yes |
| ● Step: High | Yes |
| Errors/accuracies |
| Temperature error (relative to input range), (+/-) | 25 °C ±0.1 % / -20 °C to 60 °C ±0.2 % of the full-scale deflection |
| Basic error limit (operational limit at 25 °C) |
| ● Voltage, relative to input range, (+/-) | 0.1 % |
| ● Current, relative to input range, (+/-) | 0.1 % |
| Interference voltage suppression for f = n x (f1 +/- 1 %), f1 = interference frequency |
| ● Common mode voltage, max. | 12 V |
| Interrupts/diagnostics/status information |
| Diagnostics function | Yes |
| Alarms |
| ● Diagnostic alarm | Yes |
| Diagnoses |
| ● Monitoring the supply voltage | Yes |
| ● Wire-break | Yes |
| Diagnostics indication LED |
| ● DIAG LED | Yes |
| ● for status of the inputs | Yes |
| Degree and class of protection |
| IP degree of protection | IP20 |
| Standards, approvals, certificates |
| Siemens Eco Profile (SEP) | Siemens EcoTech |
| CE mark | Yes |
| CSA approval | No |
| UL approval | Yes |
| cULus | Yes |
| FM approval | No |
| RCM (formerly C-TICK) | Yes |
| KC approval | Yes |
| Marine approval | No |
| Ecological footprint |
| ● environmental product declaration | Yes; type 2 acc. to ISO 14021 |
| Global warming potential |
| — global warming potential, (total) [CO2 eq] | 32.2 kg |
| — global warming potential, (during production) [CO2 eq] | 7.96 kg |
| — global warming potential, (during operation) [CO2 eq] | 24.5 kg |
| — global warming potential, (after end of life cycle) [CO2 eq] | -0.358 kg |
| Ambient conditions |
| Free fall |
| ● Fall height, max. | 0.3 m; five times, in product package |
| Ambient temperature during operation |
| ● min. | -20 °C |
| ● max. | 40 °C; at max. voltages and max. specifications |
| ● horizontal installation, min. | -20 °C |
| ● horizontal installation, max. | 60 °C; at rated voltages, 50 % of max. specification and alternate IO active |
| ● vertical installation, min. | -20 °C |
| ● vertical installation, max. | 50 °C; at rated voltages, 50 % of max. specification and alternate IO active |
| Ambient temperature during storage/transportation |
| ● min. | -40 °C |
| ● max. | 70 °C |
| Air pressure acc. to IEC 60068-2-13 |
| ● Operation, min. | 540 hPa |
| ● Operation, max. | 1 140 hPa |
| ● Storage/transport, min. | 540 hPa |
| ● Storage/transport, max. | 1 140 hPa |
| Altitude during operation relating to sea level |
| ● Installation altitude, min. | -1 000 m |
| ● Installation altitude, max. | 5 000 m; Restrictions for installation altitudes > 2 000 m, see manual |
| Relative humidity |
| ● Operation at 25 ℃ without condensation, max. | 95 % |
| Vibrations |
| ● Vibration resistance during operation acc. to IEC 60068-2-6 | 3.5 mm from 5 - 8.4 Hz, 1g from 8.4 - 150 Hz |
| ● Operation, tested according to IEC 60068-2-6 | Yes |
| Shock testing |
| ● tested according to IEC 60068-2-27 | Yes; IEC 68, Part 2-27 half-sine: strength of the shock 15 g (peak value), duration 11 ms |
| Pollutant concentrations |
| ● SO2 at RH < 60% without condensation | S02: < 0.5 ppm; H2S: < 0.1 ppm; RH < 60 % condensation-free |
| connection method |
| required front connector | No |
| Mechanics/material |
| Enclosure material (front) | |
| ● Plastic | Yes |
| Dimensions |
| Width | 30 mm |
| Height | 125 mm |
| Depth | 100 mm |
| Weights |
| Weight, approx. | 175 g |
| Approvals / Certificates |