Siemens 6ES7421-1EL00-0AA0

SM 421 digital input, 32 DI, 120 V AC/DC

Read from the product label

Maker: Siemens
Part no.: 6ES7421-1EL00-0AA0
Serial / rev.: as printed on your unit

Image is for illustrative purposes only. Please refer to product description.

Delivery options

Siemens SIMATIC S7-400 SM 421 digital input module: 32 isolated inputs for 120 V AC or DC, in groups of 8.

Manufacturer: Siemens
Manufacturer part no.: 6ES7421-1EL00-0AA0
Product family: SIMATIC S7-400 PLC CPUs, I/O and Function Modules
Type: Digital input module
Category: PLCs and I/O › Digital I/O modules
Lifecycle: Discontinued
OEM successor: Not stated
Technical datasheet: Data sheet

Technical specifications

Manufacturer: Siemens
Manufacturer part no.: 6ES7421-1EL00-0AA0
Type: Digital input module
Application: Digital input module
Used with: SIMATIC S7-400 rack
Input current / from backplane bus 5 V DC, max.: 200 mA
Power loss, typ.: 6.5 W
Number of digital inputs: 32
Digital inputs / Input characteristic according to IEC 61131: Type 1
Number of simultaneously controllable inputs / Number of simultaneously controllable inputs: 32
Input voltage / Type of input voltage: AC/DC
Input voltage / Rated value (UC): 120 V; 47 ... 63 Hz
Input voltage / for signal "0": 0 to 20 V UC
Input voltage / for signal "1": 79 to 132 V AC; 80 to 132 V DC
Input current / for signal "0", min.: 0 mA
Input current / for signal "0", max. (permissible quiescent current): 1 mA
Input current / for signal "1", typ.: 2 mA; 2 to 5 mA
Input delay (for rated value of input voltage) / for standard inputs / at "0" to "1", min.: 5 ms
Input delay (for rated value of input voltage) / for standard inputs / at "0" to "1", max.: 25 ms; 10 / 20 ms
Input delay (for rated value of input voltage) / for standard inputs / at "1" to "0", min.: 5 ms
Input delay (for rated value of input voltage) / for standard inputs / at "1" to "0", max.: 25 µs
Cable length / shielded, max.: 1 000 m
Cable length / unshielded, max.: 600 m
Connectable encoders / 2-wire sensor: Yes
Connectable encoders / 2-wire sensor / permissible quiescent current (2-wire sensor), max.: 1 mA
Diagnostics indication LED / Status indicator digital input (green): Yes
Potential separation digital inputs / between the channels: Yes
Potential separation digital inputs / between the channels, in groups of: 8
Potential separation digital inputs / between the channels and backplane bus: Yes
Isolation tested with: 1 500 V AC

Show all 34 specifications

Width: 25 mm
Height: 290 mm
Depth: 210 mm
Weight, approx.: 600 g

Technical documents (1)

Siemens data sheet 6ES7421-1EL00-0AA0

Key features

32 digital inputs, 120 V AC (47 to 63 Hz) or DC
Signal "1" at 79 to 132 V AC or 80 to 132 V DC
Isolated in groups of 8
Input delay up to 25 ms
Discontinued by Siemens on 1 October 2026

About the Siemens 6ES7421-1EL00-0AA0

The Siemens 6ES7421-1EL00-0AA0 is the 120 V version of the 32-channel SM 421: it reads AC or DC signals at 120 V where the 6ES7421-1BL01-0AA0 reads 24 V DC. Siemens's data sheet gives signal "1" at 79 to 132 V AC or 80 to 132 V DC, 2 to 5 mA input current, isolation in groups of 8 and 6.5 W typical power loss. SiePortal shows its phase-out announced on 1 October 2025 and its product cancellation on 1 October 2026.

What is the 6ES7421-1EL00-0AA0 used for?

It reads 120 V AC or DC signals from switches and contacts into an S7-400 CPU.

Lifecycle and successor

Discontinued.

Before you order

What to photograph or confirm so the right unit is quoted.

Check the order number and the input voltage on the module: this one is for 120 V AC or DC.

Other parts in the Siemens SIMATIC S7-400 family

Listed for reference. They differ from the 6ES7421-1EL00-0AA0 in rating, supply, interface or function and are not interchangeable with it unless Siemens says so. Match the part number on your unit.

Product	Type	Lifecycle	Qty Available	Price	Action
Siemens 6ES7417-4XT05-0AB0CPU 417-4, 30 MB, MPI, PROFIBUS DP and 2 IF slots	PLC CPU	Discontinued	On Request	On request	View
Siemens 6ES7414-4HM14-0AB0CPU 414-4H for S7-400H/F/FH, 2.8 MB, MPI/DP, DP and 2 sync interfaces	Redundant PLC CPU (H-CPU)	Discontinued	On Request	On request	View
Siemens 6ES7416-3FS07-0AB0CPU 416F-3 PN/DP fail-safe, 16 MB, MPI/DP, PROFINET and IF slot	Safety PLC CPU (F-CPU)	Phased out	On Request	On request	View
Siemens 6ES7421-1BL01-0AA0SM 421 digital input, 32 DI, 24 V DC	Digital input module	Discontinued	On Request	On request	View
Siemens 6ES7422-1BL00-0AA0SM 422 digital output, 32 DO, 24 V DC, 0.5 A	Digital output module	Discontinued	On Request	On request	View
Siemens 6ES7421-7BH01-0AB0SM 421 digital input, 16 DI, 24 V DC, interrupt and diagnostics	Digital input module	Discontinued	On Request	On request	View
Siemens 6ES7421-1FH20-0AA0SM 421 digital input, 16 DI, 120/230 V AC/DC	Digital input module	Discontinued	On Request	On request	View
Siemens 6ES7421-7DH00-0AB0SM 421 digital input, 16 DI, 24 to 60 V AC/DC, interrupt and diagnostics	Digital input module	Discontinued	On Request	On request	View
Siemens 6ES7422-1BH11-0AA0SM 422 digital output, 16 DO, 24 V DC, 2 A	Digital output module	Discontinued	On Request	On request	View
Siemens 6ES7422-7BL00-0AB0SM 422 digital output, 32 DO, 24 V DC, 0.5 A, diagnostics	Digital output module	Discontinued	On Request	On request	View
Siemens 6ES7422-1FH00-0AA0SM 422 digital output, 16 DO, 120/230 V AC, 2 A	Digital output module	Discontinued	On Request	On request	View
Siemens 6ES7422-1HH00-0AA0SM 422 relay output, 16 DO, 5 A	Digital output module	Discontinued	On Request	On request	View

You may also be interested in

TimControls is an independent distributor. Manufacturer names and logos are the property of their respective owners and identify products we source; they do not imply manufacturer authorization or affiliation.

Need Siemens 6ES7421-1EL00-0AA0? Send us the details.

Request a Quote