Decrypt Your
Siemens NCU Error Codes

Enter the error code from your machine's 7-segment display to instantly decode what it means. Get detailed diagnostics, troubleshooting steps, and part information for SINUMERIK 840D & 810D systems.

Select your system:

Current

SINUMERIK

840D / 840D sl / 810D Error Code Diagnostics

CNC machine control systems for machining centers, lathes, and multi-axis machines

Supported Control Units:

NCU 571.5NCU 572.5NCU 573.5CCU
Error Code Format:0-9, A-F (hexadecimal)

SINAMICS

S120 Fault Code & LED Diagnostics

Modular drive systems for servo and vector applications

Supported Control Units:

CU320-2 DPCU320-2 PNCU310-2 DPCU310-2 PN
Error Code Format:Fxxxxx (Fault) / Axxxxx (Alarm)

Input Controls

Dot Status

7-Segment Display

Click LEDs to cycle through states

Note: All 3 supported models (840D, 840D sl, 810D) share the same diagnostic manual (6FC5297) and use compatible error codes.

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NCU.info

What this tool does: This diagnostic tool helps CNC machine operators, maintenance technicians, and industrial engineers quickly understand and fix errors in Siemens SINUMERIK Numerical Control Units (NCU) and Compact Control Units (CCU).

How to use: Locate the hexadecimal error code (0-9, A-F) displayed on your NCU or CCU 7-segment display. Enter it into the search field above along with the dot state (none, flashing, or solid) to receive instant diagnostic information including the official error meaning, severity level, and practical troubleshooting steps.

Supported systems: SINUMERIK 840D, 840D sl (NCU modules) and SINUMERIK 810D (CCU modules). Both systems use the same diagnostic codes as documented in the official Siemens diagnostic manual 6FC5297.

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Data derived from Official SINUMERIK Diagnostics Manual (6FC5297). Check Error Codes in Official Manual

Not affiliated with Siemens AG. Independent diagnostic aid.