Siemens SINUMERIK 840D sl / ONE troubleshooting
The SINUMERIK 840D sl is Siemens’ high-end CNC, with SINAMICS S120 drives. Its alarms are numbered by source: NC alarms below 100000, HMI alarms from 100000, SINAMICS drive alarms from 200000 and PLC alarms higher still. Axis and spindle alarms are in the 20000–29999 range, and in the axis alarm text %1 is replaced by the axis name or spindle number.
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How it reports faults
- Each alarm is identified by its number and alarm text; the Diagnostics Manual gives the explanation, the system reaction, the remedy and how to clear it (“program continuation”).
- Number ranges: 000000–009999 general NC, 010000–019999 channel, 020000–029999 axis/spindle (027000–027999 Safety Integrated), 100000–169999 HMI and Operate, 200000–299999 SINAMICS.
- SINAMICS messages appear as 2 followed by five digits; replace the first 2 with F (fault), A (alarm), N or C to look them up in the SINAMICS S120/S150 List Manual (e.g. 207016 = F07016).
- How an alarm is cleared depends on its type: power-on alarms (e.g. 25000) need the control switched off and on, reset alarms (e.g. 25040, 25050) clear with RESET in all channels of the mode group, others with the Delete key or NC START.
Fault codes
| Code | Name |
|---|---|
| 25000 | Axis hardware fault of active encoder |
| 25040 | Axis standstill monitoring |
| 25050 | Axis contour monitoring |
| 10620 | Block axis at software limit switch |
| 10621 | Axis rests on software limit switch |
| 20000 | Axis reference cam not reached |
| 20001 | Axis no cam signal present |
| 20002 | Axis zero marker not found |
| 20005 | Axis reference point approach canceled |
| 21612 | Axis enable reset |
| 21614 | Axis hardware limit switch |
| 25001 | Axis hardware fault of passive encoder |
| 25010 | Axis pollution of measuring system |
| 25020 | Axis zero mark monitoring of active encoder |
| 25022 | Axis encoder warning (absolute encoder not adjusted) |
| 25030 | Axis actual velocity alarm limit |
| 25042 | Axis standstill monitoring during torque/force limitation |
| 25060 | Axis speed setpoint limitation |
| 25080 | Axis positioning monitoring |
| 25105 | Axis measuring systems differ considerably |
| 25201 | Axis drive fault |
| 25202 | Axis waiting for drive |
| 26101 | Axis drive communication failure |
Evidence to collect
- Photo of the alarm line including the axis name
- Alarm log around the event
- Any SINAMICS alarms (2xxxxx) at the same time
- What the axis was doing: standstill, positioning, contouring, reference point approach
- Recent changes to machine data, drive parameters or mechanics
Work on fuel trains, burners, pressure vessels and electrical equipment must be done by qualified personnel following the manufacturer’s documentation and local codes. Never bypass a safety device or interlock.