Product Overview
Applications
The module provides isolated digital input channels for AC/DC signals.
Technical Summary
| Digital inputs | 32 |
|---|---|
| Input voltage type | AC/DC |
| Rated input voltage | 120 V; 47 … 63 Hz |
| Input characteristic | Type 1 according to IEC 61131 |
| Simultaneously controllable inputs | 32 |
| Signal "0" input voltage | 0 to 20 V UC |
| Signal "1" input voltage | 79 to 132 V AC; 80 to 132 V DC |
| Isolation test | 1 500 V AC |
| Power loss, typ. | 6.5 W |
Key Features
The SM 421 has 32 digital inputs, with 32 inputs simultaneously controllable.
Input voltage type is AC/DC; the rated value is 120 V at 47 … 63 Hz.
The digital inputs have an input characteristic according to IEC 61131, Type 1.
The digital inputs have potential separation between channels and between channels and the backplane bus; channel separation is in groups of 8.
Isolation is tested with 1 500 V AC. Dimensions are 25 mm wide, 290 mm high, and 210 mm deep.
Frequently Asked Questions
What is the exact product model?
The exact product model is Siemens 6ES7421-1EL00-0AA0, SIMATIC S7-400 SM 421 digital input module.
How many digital inputs does the module have?
It has 32 digital inputs, and 32 inputs are simultaneously controllable.
What input voltage does it use?
The input voltage type is AC/DC, with a rated value of 120 V at 47 … 63 Hz.
What cable lengths are supported?
The maximum shielded cable length is 1 000 m, and the maximum unshielded cable length is 600 m.
