Product Overview
Technical Summary
| Product designation | SIMATIC S7-400, digital input SM 421, isolated 16 DI; UC 120/230V Inputs according to IEC1131-2 Type 2 |
|---|---|
| Digital inputs | 16 |
| Input voltage | AC/DC |
| Rated input voltage | 230 V; 120/230 V UC (47 … 63 Hz) |
| Input characteristic | Type 2 according to IEC 61131 |
| Simultaneously controllable inputs | 16 |
| Backplane bus input current | 5 V DC, max. 80 mA |
| Electrical isolation | Between channels, in groups of 4, and between channels and backplane bus |
| Isolation test voltage | 1 500 V AC |
| Product lifecycle | Announcement of product phase-out |
Key Features
- Product designation: SIMATIC S7-400, digital input SM 421, isolated 16 DI; UC 120/230V Inputs according to IEC1131-2 Type 2.
- Digital inputs: 16 digital inputs; all 16 inputs can be controlled simultaneously.
- Input voltage: AC/DC input voltage; rated value: 230 V and 120/230 V UC (47 … 63 Hz).
- Input signal ranges: Signal "0": 0 to 40 V AC / -40 to +40 V DC. Signal "1": 74 to 264 V AC; 80 to 264 V DC, -80 to -264 V.
- Electrical isolation: Digital inputs are electrically isolated between channels, in groups of 4, and between the channels and the backplane bus. Isolation tested with 1 500 V AC.
- Module dimensions: Width: 25 mm; height: 290 mm; depth: 210 mm. Weight, approx.: 650 g.
Frequently Asked Questions
What does Siemens order number 6ES7421-1FH20-0AA0 identify?
It identifies a SIMATIC S7-400 digital input SM 421 module with isolated 16 DI, AC/DC inputs, 120/230 V UC, and Type 2 input characteristics according to IEC 61131-2.
Which specifications distinguish this MLFB variant?
The distinguishing supplied specifications are 16 digital inputs, 120/230 V UC (47 … 63 Hz), Type 2 input characteristics, electrical isolation in groups of 4, and 1 500 V AC isolation testing.
What code and nameplate details should be checked before inquiry?
Check the complete order number 6ES7421-1FH20-0AA0 and confirm the SM 421 designation, 16 DI configuration, AC/DC input voltage, and 120/230 V UC rating.
What quantity and destination are needed for a quotation?
Provide the required quantity and destination together with the complete order number 6ES7421-1FH20-0AA0.
