| SIMATIC S7-1200, Analog input, SM 1231, 8 AI, +/-10 V, +/-5 V, +/-2.5 V, or 0-20 mA/4-20 mA, 12 bit+sign or (13 bit ADC) |
| General information |
| Product type designation | SM 1231, AI 8x13 bit |
| Supply voltage |
| Rated value (DC) | |
| 24 V DC | Yes |
| Input current |
| Current consumption, typ. | 45 mA |
| from backplane bus 5 V DC, typ. | 90 mA |
| Power loss |
| Power loss, typ. | 1.5 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. | 625 µs |
| Input ranges |
| Voltage | Yes; ±10V, ±5V, ±2.5V |
| Current | Yes; 4 to 20 mA, 0 to 20 mA |
| Thermocouple | No |
| Resistance thermometer | No |
| Resistance | Yes |
| Input ranges (rated values), voltages |
| -10 V to +10 V | Yes |
| Input resistance (-10 V to +10 V) | ≥9 MOhm |
| -2.5 V to +2.5 V | Yes |
| Input resistance (-2.5 V to +2.5 V) | ≥9 MOhm |
| -5 V to +5 V | Yes |
| Input resistance (-5 V to +5 V) | ≥9 MOhm |
| Input ranges (rated values), currents |
| 0 to 20 mA | Yes |
| Input resistance (0 to 20 mA) | 280 Ω |
| 4 mA to 20 mA | Yes |
| Input resistance (4 mA to 20 mA) | 280 Ω |
| Thermocouple (TC) |
| Temperature compensation |
| — parameterizable | No |
| Analog value generation for the inputs |
| Integration and conversion time/resolution per channel |
| Resolution with overrange (bit including sign), max. | 12 bit; + sign |
| Integration time, parameterizable | Yes |
| Interference voltage suppression for interference frequency f1 in Hz | 40 dB, DC to 60 V for interference frequency 50 / 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%, to 55 °C ±0.2% total measurement range |
| 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 |
| Alarms | Yes |
| Diagnostics function | Yes |
| Alarms |
| Diagnostic alarm | Yes |
| Diagnostic messages |
| Monitoring the supply voltage | Yes |
| Wire-break | Yes |
| Diagnostics indication LED |
| for status of the inputs | Yes |
| for maintenance | Yes |
| Degree and class of protection |
| Degree of protection acc. to EN 60529 | |
| IP20 | Yes |
| Standards, approvals, certificates |
| CE mark | Yes |
| CSA approval | Yes |
| FM approval | Yes |
| RCM (formerly C-TICK) | Yes |
| Marine approval | Yes |
| Ambient conditions |
| Free fall |
| Fall height, max. | 0.3 m; five times, in product package |
| Ambient temperature during operation |
| min. | -20 °C |
| max. | 60 °C |
| horizontal installation, min. | -20 °C |
| horizontal installation, max. | 60 °C |
| vertical installation, min. | -20 °C |
| vertical installation, max. | 50 °C |
| Ambient temperature during storage/transportation |
| min. | -40 °C |
| max. | 70 °C |
| Air pressure acc. to IEC 60068-2-13 |
| Operation, min. | 795 hPa |
| Operation, max. | 1 080 hPa |
| Storage/transport, min. | 660 hPa |
| Storage/transport, max. | 1 080 hPa |
| Relative humidity |
| Operation at 25 ℃ without condensation, max. | 95 % |
| 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 | Yes |
| Mechanics/material |
| Enclosure material (front) | |
| Plastic | Yes |
| Dimensions |
| Width | 45 mm |
| Height | 100 mm |
| Depth | 75 mm |
| Weights |
| Weight, approx. | 180 g |
| last modified: | 03/13/2019 |
