The common NCK alarm codes for Siemens 840DSL CNC system are mainly related to power supply, communication, hardware faults, etc. The specific codes are as follows:

1100 (no valid firmware)

Fault location: Failure to insert a storage card or absence of valid firmware (license) in the inserted storage card, resulting in the system being unable to load and run programs properly.

Repair method: Record the error message and contact Siemens professional service department; After inserting a storage card with matching valid firmware, shut down the control system and restart it.

2100-2102 (NCK battery related alarm)

Fault location: These three codes all point to the NCK battery undervoltage issue. 2100 is when the battery reaches the warning threshold; 2101 detected undervoltage during cyclic operation; 2102 detects battery undervoltage when the system is powered on, which can cause serious issues such as NC not being ready, startup being disabled, and loss of machine data, user programs, etc.

Repair method: Immediately replace the NCK battery. If data loss occurs, the system needs to be reinitialized and backup data restored. After restoration, real-time data of tools, workpieces, etc. should be checked to ensure that it matches the current machine tool status.

2130 (encoder or analog-to-digital converter undervoltage)

Fault location: If the 5V/24V power supply of the encoder or the ± 15V power supply of the digital to analog converter fails, it will cause problems such as NC switching to tracking mode and axis needing to return to the reference point.

Repair method: Disconnect the encoder cable and check if the fault has disappeared, in order to investigate whether there is a short circuit in the encoder and cable; At the same time, check the power supply circuit to confirm whether the output of the power supply module is normal, repair the power supply fault, and restart the control system.

2140 (Static Random Access Memory will be cleared during the next power on)

Fault location: The initialization switch is in the overall reset position, and the NC data storage information in the static random access memory will be deleted during the next module reset.

Repair method: Reset the initialization switch to position 0 without any additional operation, and the alarm prompt will disappear on its own.

2000, 2001 (PLC communication related alarms)

Fault location: 2000 indicates that the PLC did not send a working signal within the set time; In 2001, the PLC did not complete the startup within the timeout period, mainly due to PLC user program lag and unreasonable monitoring time parameter settings.

Repair method: Check the PLC cycle timeout parameter (MD10100) and PLC start timeout parameter (MD10120) in the machine tool data, and adjust them according to the actual situation; Check the PLC user program, locate and eliminate fault points such as program loops or shutdowns, and then restart the system.

150201 (NCK communication failure)

Fault location: mostly due to NCU module faults, abnormal communication cables, or unstable power supply. The normal NCU digital tube should display "6". If the display is abnormal or the indicator light flashes, it indicates that the NCU self-test has failed; The false connection, oxidation, or improper terminal resistance configuration of the communication cable between NCU and MCP panel can also trigger this alarm.

Repair method: First check the NCU status. If the self-test fails, repair or replace the module; Check the purple communication cable again, replace it if it is damaged, and confirm that the 120 Ω terminal resistor configuration is correct; Finally, check the stability of the 24V power supply. If the fluctuation exceeds the standard, replace the power module. If necessary, perform NCK overall cleaning and PLC reset to restore parameters.

70006 (NCK controller temperature high)

Fault location: The core cause is NCK fan failure, such as the fan stopping due to dust blockage or the fan itself burning out, resulting in poor heat dissipation of the controller and triggering a temperature alarm.

Repair method: Open the control cabinet to check the status of the NCK fan, clean the fan dust or replace the damaged fan; The parameter MD11415 can also be temporarily written to the 2 (H) value to shield the fan alarm, but in the long term, it needs to beResolve the issue of fan cooling.

3000 (total stop alarm)

Fault location: The emergency stop signal sent by the PLC to NCK is abnormal. The corresponding interface signal in the 840DSL system is DBIO. DBX56.1. When the signal is 1, an emergency stop alarm will be triggered. Common causes include pressing the emergency stop button, collision of the emergency stop block, etc.

Repair method: First check the status of the emergency stop button and whether the mechanical stopper is normal, and remove the emergency stop trigger source; Further verify the PLC-NCK emergency stop interface signal through the system backend. If the signal is abnormal, investigate the emergency stop related logic in the PLC program, repair it, and confirm the emergency stop reset according to the standard process.