Siemens 6FC5357-0BB55-0AE0 | SINUMERIK 840D/DE NCU 571.5 Control Unit

Product Overview
The Siemens 6FC5357-0BB55-0AE0 is an NCU (Numerical Control Unit) 571.5 module for the SINUMERIK 840D and 840DE powerline CNC systems. This variant features the latest hardware revision within the NCU 571.5 series, representing the most up-to-date entry-level version available for legacy system maintenance.

The NCU integrates a COM CPU board, a PLC CPU board, and a DRIVE board, and is equipped with OPI, MPI, and Profibus interfaces .

Technical Specifications

Product Lifecycle Notice
⚠️ This product belongs to the SINUMERIK 840D powerline series, which has been discontinued by Siemens. Available as a spare/replacement part only.

Normal Operation Status
Under normal conditions, after power-on and successful self-test, the NCU digital display shows "6" with two green LEDs illuminated. The NCU performs a self-test during startup - the digital display digits jump and LEDs flash during this process .

Key Features

• Latest hardware revision of the NCU 571.5 module

• Direct replacement for all earlier -0BB5x versions (-0BB51 through -0BB54)

• Enhanced entry-level NCU for SINUMERIK 840D/DE systems

• Integrated COM CPU, PLC CPU, and DRIVE boards 

• OPI, MPI, and PROFIBUS communication interfaces 

• Preferred choice for spare parts inventory

Why Choose -0BB55 Over Earlier Versions

• Latest and most mature hardware revision for NCU 571.5

• Fully backward compatible with all older versions

• Recommended for new spare parts stock

• May include component improvements from later production batches

Typical Applications

• Direct replacement for any NCU 571.5 in existing systems

• SINUMERIK 840D/840DE powerline CNC machine tools

• Spare parts inventory for legacy entry-level CNC systems

What's Included

• 6FC5357-0BB55-0AE0 NCU 571.5 module

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