Product Overview

The Siemens 6ES5482-7LF21 is a high-performance digital input/output module engineered for the SIMATIC S5 programmable logic controller family, specifically designed for integration with the S5-115F fail-safe PLC system. This versatile mixed I/O module provides 16 floating digital inputs and 16 digital outputs within a single 40mm wide standard slot, delivering exceptional channel density and electrical isolation for safety-critical and noise-sensitive industrial applications. The 6ES5482-7LF21 serves as a compact and efficient solution for applications requiring balanced input and output capacity, eliminating the need for separate input and output modules and reducing overall system footprint.

Belonging to the 482 sub-series within the SIMATIC S5 line, the Siemens 6ES5482-7LF21 is specifically designed for the S5-115U and S5-115F central expansion racks. The module’s floating (galvanically isolated) design ensures reliable operation in noise-prone environments by providing electrical isolation between the field-side signals and the backplane logic. With 16 digital inputs rated at 24V DC and 16 digital outputs rated at 0.5A per channel with negative switching capability, the 6ES5482-7LF21 offers a robust solution for demanding automation tasks. The module operates across a wide temperature range of -25°C to +60°C and carries an IP20 protection rating, making it suitable for cabinet installation in harsh industrial conditions. As the SIMATIC S5 platform has been discontinued since the mid-1990s, the Siemens 6ES5482-7LF21 has become a vital spare part for facilities still operating these robust control systems, offering a reliable path to sustaining legacy automation infrastructure.

 

Technical Specifications

Parameter Name	Parameter Value
Product Model	6ES5482-7LF21
Manufacturer	Siemens (Germany)
Product Type	Digital Input/Output Module (482 Series)
PLC Series	SIMATIC S5 (S5-115U / S5-115F)
Number of Inputs	16 digital inputs, floating/isolated
Number of Outputs	16 digital outputs, negative switching
Rated Supply Voltage	24V DC
Input Voltage (Logic 1)	11–30V DC (nominal 24V)
Input Voltage (Logic 0)	≤ 5V DC
Input Current per Channel	Approx. 7mA at 24V DC
Output Current per Channel	0.5A at 24V DC (resistive load)
Switching Type	Negative switching (low-side switch)
Input Delay	Typical 1–3 ms (with filtering)
Isolation Type	Floating/Galvanically isolated (potential-separated)
Module Width	40 mm (S5 central rack standard slot)
Weight	Approx. 0.5–0.7 kg
Operating Temperature	-25°C to +60°C
Storage Temperature	-25°C to +70°C
Protection Class	IP20 (cabinet installation only)
Front Connector	Standard 46-pin screw terminal type
Application Compatibility	S5-115F fail-safe PLC system
Product Lifecycle	PM490/PM500 – Discontinued, no direct replacement

 

Main Features and Advantages

Integrated I/O architecture: The Siemens 6ES5482-7LF21 combines 16 digital inputs and 16 digital outputs on a single compact module, offering a balanced I/O solution that reduces module count, saves cabinet space, and simplifies system wiring. This integrated design is particularly advantageous for applications requiring a mix of sensors and actuators, as it minimizes the number of slots required within the S5-115F central rack. The 6ES5482-7LF21 delivers the flexibility to handle complex control scenarios with a single module type, reducing spare parts inventory complexity.

Floating isolation and noise immunity: The Siemens 6ES5482-7LF21 features a floating (galvanically isolated) design that creates a robust electrical barrier between the field-side 24V signals and the S5 backplane logic. This floating architecture effectively protects the CPU and system electronics from ground loops, common-mode voltages, and electromagnetic interference that are endemic to industrial environments. The 6ES5482-7LF21 is particularly well-suited for S5-115F safety applications, where isolation integrity is critical for maintaining reliable operation in safety-related circuits. The module’s high noise immunity ensures accurate signal detection even in electrically noisy environments with multiple motors, drives, and heavy industrial equipment.

Negative switching output capability: The Siemens 6ES5482-7LF21 employs negative switching (low-side switching) for its 16 digital outputs, where each output terminal switches the 0V side of the load while the positive side connects to the external +24V supply. This configuration is particularly useful for applications requiring negative logic control and offers compatibility with a wide range of industrial actuators. The 6ES5482-7LF21 provides reliable control of relays, contactors, solenoid valves, and indicator lamps with a rated current of 0.5A per channel, supporting moderate current demands while maintaining protection against overload conditions.