|  | SM331, 8AI, 0/4-20MA HART | 
| General information |  | 
| Product function |  | 
| ● Isochronous mode | No | 
| Supply voltage |  | 
| Load voltage L+ |  | 
| ● Rated value (DC) | 24 V | 
| ● Reverse polarity protection | Yes | 
| Input current |  | 
| from load voltage L+ (without load), max. | 20 mA | 
| from backplane bus 5 V DC, max. | 120 mA | 
| output voltage / header |  | 
| supply voltage of the transmitters / header |  | 
| ● product function / supply voltage for transmitters | Yes | 
| ● supply voltage / of the transmitters / at DC / rated value | 24 V | 
| ● product feature / of the supply voltage for transmitters / short-circuit proof | Yes | 
| ● supply current / from supply voltage for transmitter / maximum | 60 mA | 
| Power loss |  | 
| Power loss, typ. | 1.5 W | 
| Analog inputs |  | 
| Number of analog inputs | 8 | 
| permissible input current for current input (destruction limit), max. | 40 mA | 
| Input ranges (rated values), currents |  | 
| ● 0 to 20 mA | Yes | 
| — Input resistance (0 to 20 mA) | 140 Ω | 
| ● -20 mA to +20 mA |  | 
| — Input resistance (-20 mA to +20 mA) | 140 Ω | 
| ● 4 mA to 20 mA |  | 
| — Input resistance (4 mA to 20 mA) | 140 Ω | 
| Cable length |  | 
| ● shielded, max. | 800 m | 
| Analog value generation for the inputs |  | 
| Measurement principle | Sigma Delta | 
| Integration and conversion time/resolution per channel |  | 
| ● Resolution with overrange (bit including sign), max. | 16 bit | 
| ● Integration time, parameterizable | Yes | 
| ● Integration time (ms) | 20 ms at 50 Hz; 16.6 ms at 60 Hz; 100 ms at 100 Hz | 
| ● Basic conversion time, including integration time (ms) | 55 ms @ 60 Hz, 65 ms @ 50 Hz, 305 ms @ 100 Hz | 
| ● Interference voltage suppression for interference frequency f1 in Hz | 10 / 50 / 60 Hz | 
| Smoothing of measured values |  | 
| ● parameterizable | Yes | 
| ● Step: None | Yes | 
| ● Step: low | Yes | 
| ● Step: Medium | Yes | 
| ● Step: High | Yes | 
| Encoder |  | 
| Connection of signal encoders |  | 
| ● for current measurement as 2-wire transducer | Yes | 
| ● for current measurement as 4-wire transducer | Yes | 
| Errors/accuracies |  | 
| Operational error limit in overall temperature range |  | 
| ● Current, relative to input range, (+/-) | 0.15 % | 
| Basic error limit (operational limit at 25 °C) |  | 
| ● Current, relative to input range, (+/-) | 0.1 % | 
| Interrupts/diagnostics/status information |  | 
| Diagnostics function | Yes | 
| Alarms |  | 
| ● Diagnostic alarm | Yes | 
| ● Limit value alarm | Yes | 
| Diagnostics indication LED |  | 
| ● Group error SF (red) | Yes | 
| ● Channel fault indicator F (red) | Yes | 
| Potential separation |  | 
| Potential separation analog inputs |  | 
| ● between the channels | No | 
| ● between the channels and backplane bus | Yes | 
| Isolation |  | 
| Isolation tested with | 500 V DC | 
| Degree and class of protection |  | 
| IP degree of protection | IP20 | 
| connection method / header |  | 
| required front connector | 20-pin | 
| Dimensions |  | 
| Width | 40 mm | 
| Height | 125 mm | 
| Depth | 117 mm | 
| Weights |  | 
| Weight, approx. | 205 g |