102012

Press the RECALL alarm softkey to acknowledge and clear the message from the alarm display.

Verify with the operator whether the transmission cancellation was intentional or accidental.

If cancellation was accidental, restart the data transfer operation from the beginning using the Program Manager or DNC interface.

Check the integrity of any partially transferred program files and delete incomplete programs if necessary.

Incomplete programs may cause execution errors or crashes if run. Always verify program completeness before execution.

Visually inspect the RS232C cable connections at both the SINUMERIK NCU and the external device (PC/DNC system). Check for loose or damaged connectors.

Disconnect and firmly reconnect both ends of the RS232C cable. Ensure DB9 or DB25 connector screws are properly tightened.

Power off external devices before disconnecting cables to prevent port damage.

Test cable continuity using a multimeter or replace with a known good RS232C null-modem or straight-through cable (verify correct cable type for your configuration).

Acknowledge the alarm and restart the data transfer. Monitor the connection for several minutes to ensure stability.

Check the external device (PC/DNC system) for error messages, frozen applications, or communication software crashes. Verify the device is still powered on and operational.

Restart the communication software on the external device and verify RS232 port settings match the SINUMERIK configuration (baud rate, data bits, stop bits, parity, handshaking protocol).

Access Settings > Interfaces > V24/RS232 on the SINUMERIK and verify communication parameters: typical settings are 9600-19200 baud, 8 data bits, 1 stop bit, even parity, RTS/CTS handshaking.

Perform a test transmission with a small NC program file to verify communication is restored before transferring large files.