What causes Siemens SINUMERIK alarm 6660?

Parameter or machine data configuration error. Hardware fault on the NC or drive component. Part program error or illegal command. Communication fault between NC and drive or I/O modules. Software or firmware error requiring system restart.

How do I fix Siemens SINUMERIK alarm 6660?

1. Note the complete alarm text including any axis, channel, or block number values. 2. Check for related alarms active simultaneously in the SINUMERIK alarm list. 3. Power cycle the machine to clear transient faults. 4. Review the SINUMERIK machine data for parameters related to the alarm. 5. Consult the Siemens SINUMERIK alarm manual for alarm 6660 detailed remedy.

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Siemens SINUMERIK Controller

Servo/Axis · Intermediate · 30-120 minutes

Alarm 6660

Siemens 840D 6660 - 'Flash File System' option is not set

Alarm 6660 indicates that the Flash File System (FFS) option bit is not enabled in the NCK machine data, preventing access to the NC card's non-volatile memory for storing part programs, tool data, and system files. This alarm typically occurs during system initialization when the SINUMERIK 840D attempts to mount the FFS partition but finds the enabling parameter is inactive.

Siemens SINUMERIKServo/AxisIntermediate30-120 minutes

6660

Siemens 840D 6660 - 'Flash File System' option is not set

'Flash File System' option is not set

Root Cause Summary

Alarm 6660 indicates that the Flash File System (FFS) option bit is not enabled in the NCK machine data, preventing access to the NC card's non-volatile memory for storing part programs, tool data, and system files. This alarm typically occurs during system initialization when the SINUMERIK 840D attempts to mount the FFS partition but finds the enabling parameter is inactive.

Safety

Refer to Siemens documentation
Ensure qualified technician performs repairs

Causes and Fixes

1
Access the NCK parameter editor via HMI or diagnostic interface (Siemens SINUMERIK Operate or Engineering application).
2
Navigate to Machine Data > MD 20050 and verify bit 0 is set to 1 (enabled). If 0 or parameter is missing, set to value 1.
Requires machine in READY or offline mode; online changes may require system reboot.
3
Save the machine data changes and perform a Warm Start (Control > Warm Start) or full system restart to reinitialize the NCK and FFS partition.
4
Verify alarm 6660 is cleared and NC card/FFS partition appears in the file system tree after boot completion.

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