Product Description
Key Features
- 16 isolated digital inputs: The SM 421 has 16 digital inputs, with 16 inputs simultaneously controllable.
- AC/DC input voltage: Input voltage is AC/DC; rated value is 24 V and 24 V UC to 60 V UC (47 … 63 Hz).
- Diagnostics and alarms: Diagnostics, diagnostic alarms, and hardware interrupts are available and parameterizable.
- Encoder connection: The module supports 2-wire sensors and has fixed current limitation for wire-break monitoring.
- Channel separation: Digital inputs have potential separation between channels and between channels and the backplane bus; separation is in groups of 1.
- Product lifecycle: Product lifecycle: Announcement of product phase-out.
Technical Summary
| Product | SIMATIC S7-400, digital input SM 421 |
|---|---|
| Digital inputs | 16 isolated |
| Input voltage | AC/DC; 24 V; 24 V UC to 60 V UC (47 … 63 Hz) |
| Signal 0 | -6 to +6 V DC/ 0 to 5 V AC |
| Signal 1 | 15 to 72 V DC; -15 to -72 V DC; 15 to 60 V AC |
| Diagnostics | Yes; Parameterizable |
| Product lifecycle | Announcement of product phase-out |
Frequently Asked Questions
What is the exact order number for this digital input module?
The exact order number is 6ES7421-7DH00-0AB0.
How many digital inputs does the module have?
It has 16 isolated digital inputs, with 16 inputs simultaneously controllable.
What input voltage does it use?
The input voltage is AC/DC. The rated value is 24 V and 24 V UC to 60 V UC (47 … 63 Hz).
Does it provide diagnostics and alarms?
Yes. Diagnostics, diagnostic alarms, and hardware interrupts are available and parameterizable.
