Product Overview
Technical Summary
| Product designation | SIMATIC S7-400 digital input SM 421 |
|---|---|
| Digital inputs | 16 isolated DI |
| Rated input voltage | 24 V DC |
| Input signal 0 | -30 V DC to +5 V DC |
| Input signal 1 | 11 V DC to 30 V DC |
| Input frequency, max. | 2 kHz |
| Diagnostics | Parameterizable diagnostics and diagnostic alarms |
| Isolation | Between channels in groups of 8; between channels and backplane bus |
Key Features
- Product designation: SIMATIC S7-400 digital input SM 421 with 16 isolated DI.
- Rated input voltage: 24 V DC.
- Digital inputs: 16 inputs; all 16 inputs can be controlled simultaneously.
- Input signal ranges: Signal "0": -30 V DC to +5 V DC; signal "1": 11 V DC to 30 V DC.
- Diagnostics and interrupts: Parameterizable diagnostics, diagnostic alarms, hardware interrupts, readable diagnostic information, and supply-voltage monitoring.
- Isolation: Digital inputs are electrically separated between channels in groups of 8 and between the channels and the backplane bus; isolation tested with 500 V DC.
Frequently Asked Questions
What product does Siemens 6ES7421-7BH01-0AB0 identify?
It identifies a SIMATIC S7-400 digital input SM 421 module with 16 isolated digital inputs.
Which specifications distinguish this exact module variant?
The supplied variant has 24 V DC rated input voltage, 16 digital inputs, parameterizable diagnostics, and a 0.05 ms input-delay option.
What input signal ranges should be checked?
Signal "0" is -30 V DC to +5 V DC, and signal "1" is 11 V DC to 30 V DC.
What details are needed for a quotation?
Confirm the complete code 6ES7421-7BH01-0AB0, required quantity, and destination.
