| Manufacturer part number (MPN) | 6ES7221-1BH32-0XB0 |
| EAN / GTIN | 6940408101920 |
| Sales unit | pcs |
| Product type designation | SM 1221, DI 16x24 V DC |
| 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 from backplane bus 5 V DC, max. | 130 mA |
| from load voltage L+ (without load), max. | 4 mA; per channel |
| Power supply to the transmitters | present |
| Power loss, typ. | 2.5 W |
| Number of digital inputs | 16 |
| in groups of | 4 |
| Input characteristic curve in accordance with IEC 61131, type 1 | Yes |
| Number of simultaneously controllable inputs, up to 40 °C, max. | 16 |
| horizontal installation, up to 50 °C, max. | 16 |
| Input voltage – Rated value (DC) | 24 V |
| for signal "0" | 5 V DC at 1 mA |
| for signal "1" | 15 V DC at 2.5 mA |
| for signal "0", max. (permissible quiescent current) | 1 mA |
| for signal "1", min. | 2.5 mA |
| for signal "1", typ. | 4 mA |
| Input delay parameterizable | 0.2 ms, 0.4 ms, 0.8 ms, 1.6 ms, 3.2 ms, 6.4 ms and 12.8 ms |
| Cable length shielded, max. | 500 m |
| Cable length unshielded, max. | 300 m |
| Diagnostic alarm | Yes |
| Potential separation digital inputs between the channels, in groups of | 4 |
| IP degree of protection | IP20 |
| CE mark | Yes |
| CSA approval | Yes |
| UL approval | Yes |
| FM approval | Yes |
| KC approval | Yes |
| Marine approval | Yes |
| Fall height, max. | 0.3 m; five times, in product package |
| Ambient temperature during operation – min. | -20 °C |
| Ambient temperature during operation – max. | 60 °C |
| permissible temperature change | 5°C to 55°C, 3°C / minute |
| Ambient temperature during storage/transportation – min. | -40 °C |
| Ambient temperature during storage/transportation – max. | 70 °C |
| Air pressure Storage/transport, min. | 660 hPa |
| Air pressure Storage/transport, max. | 1 080 hPa |
| Relative humidity Operation at 25 ℃ without condensation, max. | 95 % |
| required front connector | Yes |
| Enclosure material (front) | plastic |
| Dimensions – Width | 45 mm |
| Dimensions – Height | 100 mm |
| Dimensions – Depth | 75 mm |
| Weight, approx. | 210 g |
| Voltage type (supply voltage) | DC |
| Digital outputs configurable | Yes |
| Input current at signal 1 | 4 mA |
| Type of voltage (input voltage) | DC |
| Type of digital output | None |
| Short-circuit protection, outputs available | No |
| Type of electric connection | Screw connection |
| Explosion safety category for gas | ATEX gas-ex-protection, Cat. 3G |
| Explosion safety category for dust | None |
| Width | 45 mm |
| Height | 100 mm |
| Depth | 75 mm |
| Country of origin | Germany |