Product information
Overview
Key Features
- 32 isolated digital inputs: The SM 421 module has 32 isolated digital inputs, with all 32 inputs simultaneously controllable.
- 24 V DC input: The rated input voltage is 24 V DC; signal "0" is -30 V DC to +5 V DC and signal "1" is 13 V DC to 30 V DC.
- Type 1 input characteristic: The digital inputs have an input characteristic according to IEC 61131, Type 1.
- Cable length: Maximum cable length is 1 000 m for shielded cable and 600 m for unshielded cable.
- 2-wire sensor support: The module supports 2-wire sensors with a permissible quiescent current of 1.5 mA maximum.
- Product phase-out announcement: The product lifecycle is Announcement of product phase-out.
Technical Summary
| Product type | SIMATIC S7-400 SM 421 digital input module |
|---|---|
| Digital inputs | 32 |
| Input isolation | Isolated digital inputs; no potential separation between channels, in groups of 32 |
| Rated input voltage | 24 V DC |
| Input signal "0" | -30 V DC to +5 V DC |
| Input signal "1" | 13 V DC to 30 V DC |
| Input characteristic | According to IEC 61131, Type 1 |
| Backplane bus current | 5 V DC, maximum 20 mA |
| Power loss | Typical 6 W |
| Connectable sensor | 2-wire sensor; permissible quiescent current, maximum 1.5 mA |
Frequently Asked Questions
What is Siemens 6ES7421-1BL01-0AA0?
It is a SIMATIC S7-400 SM 421 digital input module with 32 isolated DI and 24 V DC input.
What input voltage ranges does this module support?
The rated input voltage is 24 V DC. Signal "0" is -30 V DC to +5 V DC, and signal "1" is 13 V DC to 30 V DC.
Can the module connect 2-wire sensors?
Yes. It supports 2-wire sensors with a permissible quiescent current of 1.5 mA maximum.
What information should I provide for a quotation?
Send the required quantity, destination, and project-list context for model-specific quotation support.
