Product Overview
Technical Summary
| Digital inputs | 16 |
|---|---|
| Simultaneously controllable inputs | 16 |
| Input voltage type | AC/DC |
| Rated input voltage | 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 |
| Diagnostic function | Yes; Parameterizable |
| Diagnostic alarm | Yes; Parameterizable |
| Hardware interrupt | Yes; Parameterizable |
| Product lifecycle | Announcement of product phase-out |
Key Features
The SM 421 module has 16 digital inputs, with all 16 inputs simultaneously controllable.
Rated input voltage is 24 V UC to 60 V UC at 47 … 63 Hz; signal "1" is 15 to 72 V DC, -15 to -72 V DC, or 15 to 60 V AC.
Diagnostics, diagnostic alarms, and hardware interrupts are available and parameterizable; wire-break detection is available at I> 0.7 mA.
The module supports 2-wire sensors and a permissible quiescent current of 0.5 mA; 0.5 to 2 mA.
Digital inputs are electrically separated between the channels and between the channels and the backplane bus; separation is in groups of 1.
Dimensions are 25 mm width, 290 mm height, and 210 mm depth; weight is approximately 600 g.
Frequently Asked Questions
What is the exact Siemens line item?
The exact line item is Siemens 6ES7421-7DH00-0AB0, a SIMATIC S7-400 SM 421 digital input module.
How many digital inputs does the module have?
It has 16 isolated digital inputs, and 16 inputs can be controlled simultaneously.
What input voltage does it support?
The input voltage type is AC/DC. The rated value is 24 V; 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.
What should be included with this line item in a quotation request?
Include the exact order number, requested quantity, destination, schedule context, and any additional BOM lines.
