Siemens 6ES5455-7LA11 Digital Output

This module provides discrete output capability for Siemens SIMATIC S5 automation systems. It drives actuators, contactors, and indicator lamps directly from the PLC. Therefore, it enables reliable control of industrial machinery and process equipment.

Physical and Output Specifications

The Siemens 6ES5455-7LA11 measures 25.0 cm in length and 18.0 cm in width. Moreover, its module weight equals approximately 0.85 kg for rack mounting. A single 32-pin removable terminal block handles all field wiring connections. Additionally, this module contains sixteen independent digital output channels.

Parameter	Specification
Brand	Siemens
Full Model	6ES5455-7LA11
Category	Digital Output Module
Dimensions (L x W x H)	25.0 cm x 18.0 cm x 5.5 cm (9.84″ x 7.09″ x 2.17″)
Module Weight	0.85 kg (1.87 lbs)
Primary Interface	1 x 32-pin Removable Screw Terminal Block
Backplane Interface	1 x 48-pin Male Connector (S5 Rack)
Output Channels	16 Independent Channels
Output Type	Transistor (PNP Sourcing)
Output Voltage Range	12 to 24 VDC
Output Current per Channel	0.5 A (Continuous), 1.0 A (Peak, 100 ms)
Total Output Current	4.0 A Maximum (All Channels Combined)
Output On-State Voltage Drop	< 1.5 VDC at 0.5 A
Output Off-State Leakage	< 0.1 mA at 24 VDC
Output Protection	Short Circuit + Overtemperature
Short Circuit Response	Automatic Shutdown + Auto-Retry (1 ms)
Switching Frequency (Resistive)	100 Hz Maximum
Switching Frequency (Inductive)	10 Hz Maximum (with Flyback Diode)
Response Time (On to Off)	0.5 ms Maximum
Response Time (Off to On)	0.5 ms Maximum
On-Board Components	16 Power Transistors + 16 Optocouplers + 16 Flyback Diodes + 1 Current Sense IC + 6 Protection Diodes + 1 Fuse
Energy Storage	3 x 220 µF Electrolytic Capacitors (35V) + 2 x 47 µF Tantalum (25V)
Operating Voltage	+5 VDC from Backplane + 24 VDC External
Power Consumption (Logic)	1.0 W (Typical)
Power Consumption (Load)	Up to 6.0 W (All Channels On)
Isolation Rating	1500 Vrms (Field to Logic)
Operating Temperature	0°C to +55°C (32°F to 131°F)
Mounting Type	S5 Rack (Single Slot)
Status Indicators	16 Green LEDs (One per Channel) + 1 Green LED (Power) + 1 Red LED (Fault) + 1 Green LED (24V OK)

Output Channel Features and Protection Systems

The Siemens 6ES5455-7LA11 uses PNP sourcing transistors for all sixteen output channels. Specifically, each output delivers 0.5 amps continuously at 24 VDC. In addition, internal flyback diodes protect the transistors when driving inductive loads. Moreover, short circuit protection shuts down any faulty channel automatically. Furthermore, auto-retry restores output operation once the fault clears. Thus, this module survives wiring mistakes without permanent damage.

Energy Storage and Operational Stability

This digital output module stores energy using five onboard capacitors for power filtering. Specifically, three electrolytic capacitors smooth the 5 VDC supply for stable optocoupler operation. In addition, two tantalum capacitors provide high-frequency noise suppression for logic circuits. Furthermore, these capacitors maintain output stability during brief power interruptions. Consequently, the Siemens 6ES5455-7LA11 continues operating through minor supply dips reliably.

High-Density Output Configuration

Sixteen output channels fit into a single S5 rack slot with this module. For instance, you can control up to sixteen solenoid valves with one module. In addition, the removable terminal block accepts 18-22 AWG stranded or solid wires. Moreover, each channel includes an independent green LED for visual status monitoring. Therefore, this module saves valuable rack space in large control systems.

Installation and Diagnostic Indicators

Eighteen LED indicators provide operational status at a glance on this module. First, sixteen green LEDs light when each corresponding output channel turns on. Second, a green Power LED indicates the presence of 5 VDC backplane supply. Third, a green 24V OK LED shows external load supply voltage is present. Finally, a red Fault LED illuminates during short circuit or overtemperature events. Thus, you can diagnose system status instantly without external tools.