Product Overview
Technical Summary
| Product designation | SIMATIC S7-400 digital input SM 421, isolated 16 DI |
|---|---|
| Digital inputs | 16 |
| Input voltage | AC/DC; 24 V UC to 60 V UC (47 … 63 Hz) |
| Simultaneously controllable inputs | 16 |
| Signal "1" input range | 15 to 72 V DC; -15 to -72 V DC; 15 to 60 V AC |
| Signal "0" input range | -6 to +6 V DC/ 0 to 5 V AC |
| Diagnostics | Yes; parameterizable |
| Diagnostic alarm | Yes; parameterizable |
| Hardware interrupt | Yes; parameterizable |
| Product lifecycle | Announcement of product phase-out |
Key Features
- Product designation: SIMATIC S7-400 digital input SM 421 with isolated 16 DI.
- Input configuration: 16 digital inputs; all 16 inputs can be controlled simultaneously.
- Input voltage: AC/DC input; rated value 24 V UC to 60 V UC (47 … 63 Hz).
- Signals and current: Signal "0": -6 to +6 V DC/ 0 to 5 V AC; signal "1": 15 to 72 V DC, -15 to -72 V DC, or 15 to 60 V AC; signal "1" input current, typ.: 4 mA; 4 to 10 mA.
- Alarms and diagnostics: Parameterizable diagnostics, diagnostic alarms, and hardware interrupts; wire-break diagnosis is available at I> 0.7 mA.
- Isolation and dimensions: Digital inputs are electrically separated from the backplane bus and between channels, in groups of 1; isolation tested with 1 500 V AC. Dimensions: 25 mm width, 290 mm height, 210 mm depth.
Frequently Asked Questions
What product does Siemens order number 6ES7421-7DH00-0AB0 identify?
It identifies a SIMATIC S7-400 digital input SM 421 with isolated 16 DI, AC/DC input, UC 24 V to 60 V, alarms and diagnostics.
Which specifications distinguish this exact module variant?
The listed variant has 16 digital inputs, 24 V UC to 60 V UC input, parameterizable diagnostics and alarms, and isolation between channels and the backplane bus.
What code and nameplate details should be checked?
Check the complete order number 6ES7421-7DH00-0AB0 and the module designation SIMATIC S7-400 digital input SM 421.
What information is needed for a quotation?
Provide the required quantity and destination when requesting a quotation.
