Siemens 6ES5155-3UA21 Programmable Controller

The 6ES5155-3UA21 serves as a programmable controller for SIMATIC S5 automation systems. This unit executes user programs and manages local I/O operations. Its rectangular frame measures 232 millimeters in width. The controller height reaches 210 millimeters exactly. Depth stays at 155 millimeters. You will find this unit weighs approximately 1.18 kilograms. Therefore, installation requires sliding the unit into a standard S5 rack slot. One 20-pin front connector provides I/O access for field devices.

Physical Layout and Connectors

The front panel features a 4-line LCD display for system diagnostics. You will find eight push buttons for local configuration access. One RS-232 serial port connects to programming software. Four status LEDs indicate run, stop, error, and power conditions. Two guide rails secure the unit firmly in the rack.

Technical Specifications

Parameter	Specification
Controller Width	232 mm
Controller Height	210 mm
Controller Depth	155 mm
Unit Weight	1.18 kg
Processor	16-bit @ 12 MHz
Program Memory	32 KB (EPROM)
Data Memory	16 KB (retentive)
Scan Time	1.2 ms per 1K instructions
Communication Port	RS-232 (programming)
Front Connector	1 x 20-pin (I/O)
Component Total	486 discrete parts
Internal Energy Storage	1000 µF capacitor bank
Backup Battery	Lithium (3.6V, 5 years)
Operating Temperature	0°C to +55°C

Internal Design and Energy Storage

The 6ES5155-3UA21 contains exactly 486 discrete components inside. A 1000 microfarad capacitor bank filters the main power supply input. This bank holds enough charge for 20 milliseconds after power loss. The 16-bit processor runs at 12 megahertz for reliable execution. A lithium battery retains data memory for up to five years. EPROM stores the user program without any battery backup required.

Operational Performance

This programmable controller executes logic from 32 kilobytes of program memory. It scans 1,000 instructions in approximately 1.2 milliseconds. Moreover, the unit handles up to 256 digital I/O points system-wide. The RS-232 port allows connection to programming software and HMIs. The LCD display shows real-time system status and diagnostic messages. Eight buttons let you navigate menus without a programming computer. Consequently, you achieve dependable control for medium-sized automation projects. Siemens designed this controller for SIMATIC S5 platform compatibility. Its rugged construction suits demanding industrial environments.

In summary, the 6ES5155-3UA21 delivers reliable programmable controller performance. Use this unit for factory automation or process control systems. It provides stable execution for S5 automation tasks. Order this programmable controller for your Siemens SIMATIC S5 system.