Siemens 6FC5357-0BB21-0AE0 SINUMERIK 840D NCU 572.2 Control Unit
Siemens 6FC5357-0BB21-0AE0 SINUMERIK 840D NCU 572.2 Control Unit
Available to order — ships when sourced
The Siemens 6FC5357-0BB21-0AE0 is a Numerical Control Unit (NCU 572.2) for SINUMERIK 840D/840DE CNC systems. It serves as the central processing module for multi-axis machine tools, handling motion control, interpolation, and automation logic. This unit comes equipped with an integrated Intel 486DX4 100MHz processor, 0.5 MB of NC user memory for part programs and tool data, and an onboard Simatic S7-300 PLC (CPU 315-2 DP) with 96 KB of PLC memory for I/O logic. The NCU 572.2 is prepared for PROFIBUS DP communication with distributed I/O and drives. Also searched as 6FC53570BB210AE0.
Specifications
| Part Number | 6FC5357-0BB21-0AE0 |
| Product Line | SINUMERIK 840D / 840DE |
| Module Type | NCU 572.2 |
| Processor | Intel 486DX4 100 MHz |
| NC User Memory | 0.5 MB |
| PLC Memory | 96 KB |
| Integrated PLC | Simatic S7-300 (CPU 315-2 DP) |
| Communication | PROFIBUS DP Prepared |
| Condition | Used-Tested |
| Warranty | 14–30 days |
Condition & testing
This unit was removed from a functioning CNC system and has been power-tested. Core control functions, processor operation, and PROFIBUS communication interface were verified. The integrated S7-300 PLC module responded correctly during bench testing. Cosmetic condition is consistent with industrial use. System software/firmware memory card is not included with this unit.
Compatibility
Compatible with SINUMERIK 840D and 840DE CNC control systems. Requires system software memory card for operation.
What's included
NCU 572.2 module only (system software/firmware memory card not included)
Compatible & Related
Compatibility notice: Part numbers are listed for identification only. Always confirm the exact part number and revision match your equipment before ordering.
Condition disclosure: Unless stated as new, items are used or refurbished and may show cosmetic signs of prior use. Functional condition is described above.
Independent reseller: Samonde is an independent reseller and is not affiliated with, authorized by, or endorsed by the original manufacturer.
Installation warning: Industrial automation components must be installed and commissioned by qualified personnel. Samonde accepts no liability for damage or injury resulting from incorrect installation or use.
FAQs
See All
What payment methods can I use?
We accept all major credit cards (Visa, Mastercard, American Express), PayPal, and bank transfers for B2B orders. For large industrial orders, we also offer invoice payment with NET-30 terms for verified business customers.
Are the parts on your website tested and genuine?
Yes. Every part sold by Samonde is professionally tested by our technicians in Tallinn before shipping. We source directly from decommissioned industrial equipment, authorized distributors, and certified surplus stock. Each item comes with a functionality warranty.
Do you offer warranties on industrial spare parts?
Absolutely. All parts come with a minimum 14-30 day warranty. Many items, especially Siemens and Heidenhain components may have include extended 90-day coverage (depends on the parts). If a part fails during the warranty period, we offer replacement or full refund.
Can you source a part that is out of stock?
Yes. If you need a specific Siemens, Heidenhain, Fanuc, or other industrial part that is currently out of stock, contact us with the part number. Our sourcing team across Europe can usually locate hard-to-find automation components within 5-10 business days.
How do I know I'm ordering the correct part for my machine?
Each product listing includes the exact manufacturer part number (MPN), compatibility notes, and photos of the actual item. If you are unsure, send us your machine model and part number via the Contact page or WhatsApp, and our engineers will verify compatibility before you purchase.
Do you ship internationally outside the EU?
Yes. Samonde ships worldwide from our EU warehouse. We offer UPS and DHL Express and standard freight options to North America, Asia, Middle East, and South America. All shipments include tracking and customs documentation.
Siemens 6FC5357-0BB21-0AE0 SINUMERIK 840D NCU 572.2 Control Unit