What causes Siemens SINUMERIK alarm 14701?

Memory corruption in the NC block buffer due to unexpected power loss or system shutdown during program execution. Defective or failing RAM module in the control cabinet causing data loss in the IPO buffer. Software crash or system error that did not properly release allocated NC blocks back to the buffer pool. Interrupted communication between the CNC controller and the programming device during block download or transfer.

How do I fix Siemens SINUMERIK alarm 14701?

1. Acknowledge the alarm and perform a soft reset of the control system; verify the number of available blocks reported in the alarm message against the MM_IPO_BUFFER_SIZE parameter 2. Check the system log for preceding errors or warnings that may indicate what caused the buffer reduction; review startup messages and any communication errors 3. Power cycle the entire CNC machine and control cabinet using the main disconnect switch, then restart and monitor if the block count returns to normal on subsequent resets 4. If the block deficit persists and exceeds safe operating margins, perform a cold restart by reinitializing the NC system parameters through the HMI diagnostic menu 5. If available blocks remain critically low after cold restart, schedule RAM diagnostics or contact Siemens service to test memory modules in the control cabinet

Siemens SINUMERIK codes

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Siemens SINUMERIK Controller

Servo/Axis · Intermediate · 30-60 minutes

Alarm 14701

Siemens 840D 14701 - Channel block number of available NC blocks reduced by

After reset, it has been found that the number of available blocks has decreased compared with the last reset. This is due to a system error. Part program execution can be resumed after the alarm has been acknowledged. If the number of blocks no longer available is less than 28060 MM_IPO_BUFFER_SIZE

Siemens SINUMERIKServo/AxisIntermediate30-60 minutes

14701

Siemens 840D 14701 - Channel block number of available NC blocks reduced by

Channel block number of available NC blocks reduced by

Safety

Refer to Siemens documentation
Ensure qualified technician performs repairs

Common Causes

Memory corruption in the NC block buffer due to unexpected power loss or system shutdown during program execution
Defective or failing RAM module in the control cabinet causing data loss in the IPO buffer
Software crash or system error that did not properly release allocated NC blocks back to the buffer pool
Interrupted communication between the CNC controller and the programming device during block download or transfer

Troubleshooting Steps

1Acknowledge the alarm and perform a soft reset of the control system; verify the number of available blocks reported in the alarm message against the MM_IPO_BUFFER_SIZE parameter
2Check the system log for preceding errors or warnings that may indicate what caused the buffer reduction; review startup messages and any communication errors
3Power cycle the entire CNC machine and control cabinet using the main disconnect switch, then restart and monitor if the block count returns to normal on subsequent resets
4If the block deficit persists and exceeds safe operating margins, perform a cold restart by reinitializing the NC system parameters through the HMI diagnostic menu
5If available blocks remain critically low after cold restart, schedule RAM diagnostics or contact Siemens service to test memory modules in the control cabinet

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