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RS232 Pin Connection Reference

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DNC Software Support

This document is for reference only

Introduction

• Create and edit CNC programs at your PC,
• Transfer programs and data between your PC and CNC,
• DNC (drip-feed) programs larger than your controls memory capacity

Testing Communications

Please follow this guide in order, and complete all steps.

Testing Communications from CNC to PC

1. Set CNC control exactly as shown in Table A at end of page
2. In DNCv5 software menu [Machine], [RS-232 Setting], set to: E, 7, 2
3. In DNCv5 software menu [Machine], [RS-232 Setting], set Baud rate to match CNC
4. In DNCv5 software menu [Machine], [RS-232 Setting], set PC port to COM on which cable is connected (use Windows Device Manager to see list of available COM ports)
5. On DNCv5 button bar, click Receive
6. Set CNC to send (punch) a G-code program
7. Wait for CNC to send entire data file, then click Done (End) button in DNCv5
8. Received file should appear in editor

Testing Communications from PC to CNC

1. On DNCv5 menu bar, click File, then click Open and open a G-code file.
   
2. Confirm that the file structure is similar (when applicable) to the following example:
   %
   O1234(PROGRAM DESCRIPTION)   
   (BODY OF PROGRAM)   
   %
   
3. Check G-code program to confirm letter O and digit 0 (zero) are not mixed up. Some machines accept : in the place of an O for program number.
   
4. On DNCv5 button bar, right-click on Send, then set CNC to receive (read), or set CNC to receive and then left-click Send. (Note:
5. For safely reasons, always follow first sequence when drip-feeding to prevent CNC from starting while unattended.)
   
6. Testing Xmodem Drip-Feed (DNC) from PC to CNC (Haas Machines Only)
   
7. Maximize buffer size by deleting unneeded programs from CNC memory. (Poor performance may result if free memory is too small.)
   
8. If control is made by Haas, set it exactly as shown in Table A at end of this page. Otherwise, use Haas settings as a guide if your CNC supports Xmodem.
   
9. Disable PC screen saver.
   
10. On DNCv5 menu bar, click Machine, then click Settings
    
11. Set DNCv5 exactly to: 38400, N, 8, 1, Xmodem.
    
12. Determine what COM number is assigned to the PC port your CNC is connected to and set DNCv5 to that number.
    
13. On DNCv5 menu bar, click File, then click Open and open a G-code file.
    
14. Click Send on DNCv5 tool bar.
    
15. Set CNC to DNC mode.
    
16. When DNCv5 starts sending data, press cycle start on CNC then immediately press feed hold. Change Haas screen to display large axis position digits (buffer will fill faster when this screen is displayed). Wait a few minutes for CNC buffer to fill, then press cycle start again.
    

Trouble Shooting: Data is not received or is received garbled

• Double-check settings
  
• Check position of manual switch box, if applicable
  
• Try each COM port, one-by-one
  
• Check for missing %, if applicable
  
• Set CNC to ASCII or ISO, not EIA
  
• Set both CNC and DNCv5 to a lower baud rate
  
• Check RS232 cable for correct wiring configuration.
  
• Make sure all connections are secure and fully seated
  
• Avoid connecting/disconnecting cables while control is on
  
• Check signals with RS232 Mini Tester
  
• Try another brand of cable
  
• Try another brand of switch box
  
• Check Windows Device Manager for COM port resource conflicts
  
• Check port at CNC, it may be disconnected or switched inside cabinet
  
• Check CNC for ground faults (voltage between machine and ground)
  
  

General Tips

• Reroute cable away from fluorescent lamps. Never run standard cable outside
• If drip-feeding to a Haas (Haas Automation Inc.), try Xmodem instead of Xon/Xoff
• Disable PC screen saver
• Close DOS programs
• Avoid using screensavers and anti-virus software while DNCv5 is running
• If possible, get cables from dncsoftware.com rather than making yourself
  
• Cascade manual switch boxes to increase number of port connections
  
• Avoid connecting and disconnecting cables while control and computer are on
  
• Never solder a wire while other end is connected to CNC or PC
  
• Use lower baud rates for smaller files
  
• Use Xmodem if CNC supports it
  
• Delete unneeded characters after last percent sign before sending file