Siemens 6ES5451-5AA12 Digital Output Module

The Siemens 6ES5451-5AA12 digital output module controls actuators and indicators in SIMATIC S5 systems. This module sends on/off signals to contactors, solenoids, and lamps. It mounts directly into any S5-115U or S5-135U rack slot. You can use this module as a direct replacement for failed units.

Detailed Technical Specifications

This Siemens 6ES5451-5AA12 digital output module measures 250 mm in length. Its width reaches 160 mm across the main body. The total height goes up to 42 mm with all components installed. This unit weighs approximately 0.52 kilograms for secure mounting.

Key hardware parameters include:

Complete Model: Siemens 6ES5451-5AA12
Component count: 72 individual electronic parts
Output channels: 16 digital transistor outputs
Connector: One 20-pin screw terminal block
Energy storage: Two electrolytic capacitors (100 µF each)
Mounting system: Two rear locking levers
Voltage rating: 24 V DC nominal
Output current: 0.5 A per channel continuously
Total current: 4 A maximum across all channels
Short-circuit protection: Electronic current limiting
Switching delay: 0.5 ms typical for on/off

The Siemens 6ES5451-5AA12 digital output module stores minimal residual charge after power-off. Therefore, technicians can perform replacements within two minutes. Each output includes an LED for visual status indication. Moreover, the module provides galvanic isolation between the backplane and field side.

Technical Parameter	Specification
Full Model Number	Siemens 6ES5451-5AA12
Board Dimensions	250 mm x 160 mm x 42 mm
Weight	0.52 kg
Total Components	72 units
Output Channels	16 transistor outputs
Connector Type	20-pin screw terminal block
Energy Storage Caps	2 x 100 µF (electrolytic)
Voltage Rating	24 V DC
Output Current	0.5 A per channel
Total Current	4 A maximum
Switching Delay	0.5 ms
Operating Temperature	0°C to +60°C
Humidity Tolerance	5% to 85% non-condensing

Application and Installation

The Siemens 6ES5451-5AA12 digital output module connects directly to 24 V DC field devices. This module drives solenoid valves, motor contactors, and indicator lights. It requires an external 24 V DC power supply for output operation. Consequently, you can control up to 16 loads from a single module.

Protection and Reliability

This module includes short-circuit protection on every output channel. Its electronic current limiter prevents damage during wiring faults. The Siemens 6ES5451-5AA12 features thermal shutdown for overload conditions. Therefore, the module recovers automatically when the fault clears.

Always power down the rack before inserting or removing this module. Wire the field devices using the terminal labeling diagram. The module features a green LED for backplane power status. Furthermore, its conformal coating protects against dust and light moisture.