Overview
Manual
Input Channels
Electrical Grouping
Commissioning Guide
Features:
- Input current: 20 mA
- Power loss: 6 W
- Number of digital inputs: 32 input
Siemens 6ES7421-1BL01-0AA0 is a SIMATIC S7-400 SM 421 isolated digital input module with 32 channels for 24 V DC process signals.
The module transfers field input states to the S7-400 backplane and uses grouped isolated circuits. Input wiring, reference potentials and channel diagnostics must be aligned with the official module data and STEP 7 hardware configuration.
Siemens lists this product in phase-out status. Verify rack compatibility, connector assignment, sensor voltage and the existing project before exchanging the module.
The Siemens 6ES7421-1BL01-0AA0 may be supplied and supported by Moore Automated according to the official product lifecycle: Active/Available from OEM.
Siemens 6ES7421-1BL01-0AA0 SIMATIC S7-400 SM 421 digital input module Manuals(Datasheets), Link
Important Notice: Other accessories, manuals, cables, calibration data, software, licenses and related items are not included with this equipment unless listed in the above stock item description. All prices are shown in USD.
Technical details:
- Input current: 20 mA
- Power loss: 6 W
- Number of digital inputs: 32 input
- Input voltage for signal: -30 V DC to 5 V DC
- Isolation tested with: 500 V AC/707 V DC
- Degree of Protection: IP20
The SM 421 reads thirty-two 24 V DC field signals into an S7-400 station. Reliable replacement requires matching the channel grouping, reference potentials, connector assignment and STEP 7 module parameters; verify field voltage and diagnostics before returning the process to service.
Compatibility: It installs in compatible SIMATIC S7-400 racks and must match the front connector, 24 V DC field circuits and STEP 7 configuration.
Configuration: Power down the rack and field circuits, verify grouped reference potentials and connector assignment, then test each channel and diagnostic indication.
Application: It collects switches, contacts and sensor states for sequence and interlock logic in S7-400 systems.
Lifecycle: Siemens lists 6ES7421-1BL01-0AA0 in phase-out status; confirm availability and migration planning.
The SM 421 reads thirty-two 24 V DC field signals into an S7-400 station. Reliable replacement requires matching the channel grouping, reference potentials, connector assignment and STEP 7 module parameters; verify field voltage and diagnostics before returning the process to service.
