SIEMENS 6ES5421-8MA12

Siemens SIMATIC S5 Digital Input Module

Description

The 6ES5421-8MA12 is a digital input module from the proven Siemens SIMATIC S5 series. It is designed to reliably process input signals for various industrial automation tasks. With 8 channels operating at 24V DC, this module is an essential component for the maintenance and expansion of existing S5-115U, S5-115H, and S5-115F PLC systems.

Specifications

• Manufacturer: Siemens
• Product Line: SIMATIC S5
• Model: 6ES5421-8MA12
• Module Type: Digital Input
• Number of Inputs: 8
• Input Voltage: 24V DC
• Compatibility: S5-115U/H/F Systems
• Galvanic Isolation: No (non-floating)

Label Info

• Part Number: 1P 6ES5 421-8MA12
• Serial Number: C-M9C83720
• E-Stand: 05

Application

This module is ideal for applications requiring the acquisition of digital signals from sensors, push-buttons, and limit switches within a SIMATIC S5 control system. It is widely used in manufacturing, process control, and material handling systems that rely on this legacy hardware.

Country of Origin

Made in Germany.

CO2 Impact

By purchasing this refurbished item, you are helping to avoid approximately 8.0 kg of CO2 emissions compared to manufacturing a new one.

Availability

This is an obsolete item, available as a spare part. Stock is limited. Order now from spareparts2day for expert support and fast delivery.

FAQ

Is this module compatible with all SIMATIC S5 PLCs?

No, this module is specifically designed for the S5-115U, S5-115H, and S5-115F series. It is not compatible with other S5 families like the S5-95U or S5-135U without the correct backplane.

What is the significance of the ‘E-Stand: 05’ on the label?

The ‘E-Stand’ or Engineering Stand represents the hardware and firmware version of the module. Version 05 is a specific revision. When replacing a module, it is best practice to match the E-Stand to ensure full compatibility and identical performance.

Does this module require a specific front connector?

Yes, SIMATIC S5 modules require a front connector for wiring. For this module, you would typically use a 20-pin front connector, such as the Siemens part number 6ES5497-4UA12 (screw type) or 6ES5497-4UB12 (crimp type).

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Last Update: Friday, March 13, 2026