Product information
Overview
Key Features
- 16 isolated digital inputs: The SM 421 has 16 digital inputs, with all 16 inputs simultaneously controllable and potential separation between channels in groups of 8.
- 24 V DC input: Rated input voltage is 24 V DC. Signal "0" is -30 V DC to +5 V DC, while signal "1" is 11 V DC to 30 V DC.
- Diagnostics and alarms: The module has parameterizable diagnostics, diagnostic alarms, hardware interrupts, readable diagnostic information, supply-voltage monitoring, and wire-break detection with I < 1 mA.
- Configurable input timing: The input is parameterizable; the minimum transition time is 3 μs, with settings of 0.05 / 0.1 / 0.5 / 3 ms. Maximum input frequency is 2 kHz.
- Encoder supply: It has 2 encoder-supply outputs with output voltage L+ (-2.5 V), electronic short-circuit protection, and possible additional redundant feed.
- Installation and isolation: Shielded cable length is up to 1 000 m and unshielded cable length up to 600 m, with the stated timing conditions. Isolation is tested with 500 V DC.
Technical Summary
| Product | 6ES7421-7BH01-0AB0 |
|---|---|
| Product type | SIMATIC S7-400 SM 421 digital input module |
| Digital inputs | 16 isolated DI |
| Rated input voltage | 24 V DC |
| Signal "0" input voltage | -30 V DC to +5 V DC |
| Signal "1" input voltage | 11 V DC to 30 V DC |
| Maximum input frequency | 2 kHz |
| Diagnostics | Parameterizable diagnostics, diagnostic alarm, and hardware interrupt |
| Encoder-supply outputs | 2 |
| Product lifecycle | Announcement of product phase-out |
Frequently Asked Questions
What is the exact product type of 6ES7421-7BH01-0AB0?
It is a Siemens SIMATIC S7-400 SM 421 digital input module with 16 isolated DI.
What input voltage does this module use?
The rated input voltage is 24 V DC. Signal "0" is -30 V DC to +5 V DC, and signal "1" is 11 V DC to 30 V DC.
Does 6ES7421-7BH01-0AB0 provide diagnostics?
Yes. It has parameterizable diagnostics, diagnostic alarms, hardware interrupts, readable diagnostic information, supply-voltage monitoring, and wire-break detection with I < 1 mA.
How many inputs can be controlled simultaneously?
All 16 digital inputs can be controlled simultaneously.
Can you quote this exact module for a project requirement?
Send the required quantity, destination, requested date, and project-list context for a model-specific quotation.
