Troubleshooting > No data received on CNC side

Problem: When trying to send data from the DNC to CNC, no data is received.

Check the port log

If no data is sent because the file is empty or does not exist, then the machine log file might give you some indication of what is wrong. For this feature, you need to enable log messages in the machine configuration. Then select a machine from the list in the main window, and now you can see log at the bottom of the window.

Check the log combo box to verify that the server is actually sending any data. If no data is sent, check the port status, in some cases the server will wait for a start of transmission signal from the CNC, if this is the case, the port status will indicate this.

Check that you are using the correct serial port

Open the configuration dialog, and check that you have selected the correct serial port.

Handshake problem

Check that you are using the correct handshake method. If hardware handshake is not enabled, try selecting Set RTS high and/or Set DTR high in the serial port configuration dialog. Some machines use non-standard software handshake characters. If this is the case change the XOn character / XOff character in the serial port configuration dialog. For further information, please refer to the Serial port section.

The CNC needs a transmission start character

Some machines need a specific character before it starts to store a file. Check the machine manual. Many machines need a % at the top of the program, some need nulls (blank tape), others need an end of block code (CR/LF). If this is the case, you should specify this in the Program start field in the configuration dialog. For further information, please refer to the Program format section.

Cycle start problem

Many machines require the program to be sent to them as soon as the cycle start button is pressed. Select transmit program at the DNC before pressing cycle start. This requires the PC to start sending when it either sees the handshake line going high (for hardware handshaking) or when it receives an XOn (for software handshaking). If software handshaking is used, then try enabling Wait for XOn before sending data in the port transmit settings. For further information, please refer to the Program format section.

Check your cable

Check that your cable is wired correctly. For information on how to wire a standard serial cable, please refer to Serial communication overview. Some machines require a special non-standard serial cable. For further information, please refer to the reference manual for your CNC.

Try another serial port

Try using another serial port, in case you have a defective serial port.