SIMATIC S7-400 SM 421 16-input 24 to 60 V AC/DC module / 6ES7421-7DH00-0AB0

6ES7421-7DH00-0AB0: SM 421 digital input module with 16 inputs. Input voltage and isolation group size follow the exact manufacturer column. Confirm configuration and current supply separately.

Manufacturer part number: 6ES7421-7DH00-0AB0
Brand: Siemens
Category: PLC and HMI
Catalog status: Request a quotation

Technical specifications

Controller family: SIMATIC S7-400
Module designation: SM 421
Digital inputs: 16
Digital outputs: 0
Rated input: 24 to 60 V AC/DC
Input isolation group size: 1 input per group
Isolation check voltage: 1500 VAC
Maximum 5 V backplane current (mA): 150
Dimensions (W x H x D): 25 x 290 x 210 mm
Approximate weight (g): 600
Document pages: PDF 54, 55, 56
Current lifecycle status: Not established by historical catalogue; confirm current lifecycle and supply separately
Interrupt support: Process/diagnostic interrupts, per exact ordering description

Manufacturer technical catalog · SIMATIC ST 400 / May 2017 · en · PDF · ST 400 / May 2017 / E86060-K4678-A151-A1-7600Manufacturer source: Siemens · Model explicitly covered in family document · Covered models: 6ES7421-7DH00-0AB0 · Checked: 2026-10-22Official manufacturer source

This sheet provides a quick technical summary. For design, installation and final selection, review the latest official manufacturer documentation and verify the complete part number.