| | SIMATIC S7-400, DIGITAL INPUT SM 421, OPTIC. ISOLATED, 16 DI, 120 V AC, WITH 1 COMMON POINT |
| |
| Supply voltage |
| Load voltage L1 |
| Rated value (AC) | 120 V |
| permissible range, lower limit (AC) | 74 V |
| permissible range, upper limit (AC) | 132 V |
| Input current |
| from backplane bus 5 V DC, max. | 100 mA |
| Power losses |
| Power loss, max. | 20 W |
| Digital inputs |
| Number/binary inputs | 16 |
| Number of simultaneously controllable inputs |
| all mounting positions |
| up to 40 °C, max. | 16 |
| up to 60 °C, max. | 16 |
| Input voltage |
| Rated value, AC | 120 V |
| for signal "0" | 0 to 20 V AC |
| for signal "1" | 74 to 132 V AC |
| Frequency range | 47 to 63 Hz |
| Input current |
| for signal "0", max. (permissible quiescent current) | 4 mA; 0 to 4 mA |
| for signal "1", typ. | 6 mA; 6 to 20 mA |
| Input delay (for rated value of input voltage) |
| for standard inputs |
| Parameterizable | Yes |
| at "0" to "1", min. | 2 ms |
| at "0" to "1", max. | 15 ms |
| Cable length |
| Cable length, shielded, max. | 1000 m |
| Cable length unshielded, max. | 600 m |
| Encoder |
| Connectable encoders |
| 2-wire sensor | Yes |
| Permissible quiescent current (2-wire sensor), max. | 4 mA |
| Galvanic isolation |
| Galvanic isolation digital inputs |
| between the channels, in groups of | 1 |
| between the channels and the backplane bus | Yes |
| Isolation |
| Isolation checked with | 1500 V AC |
| Dimensions |
| Width | 25 mm |
| Height | 290 mm |
| Depth | 210 mm |
| Weight |
| Weight, approx. | 650 g |
| Status | Mar 12, 2012 |
