RS-232 Troubleshooting
GUIDELINES
1. If no information is transferred:
| POSSIBLE PROBLEMS | SOLUTIONS |
| COM port mismatched | Plug cable in the COM port shown in the Com Setup window, OR edit the COM port to match your physical setup. |
| Cable with wrong wiring | Identify the defective cable and follow wiring instructions to re-wire the cable. |
| Cable is damaged | Identify the defective cable and replace the cable. |
| Modem / COM port IRQ conflict | Change IRQ (Interrupt Request) on your computer (communications port). |
2. If can't communicate with only one machine (transmission to/from other CNCs are OK):
| POSSIBLE PROBLEMS | SOLUTIONS |
| Defective switchbox | Replace switchbox. |
| Cable with wrong wiring | Identify the defective cable and follow wiring instructions to re-wire the cable. |
| Cable is damaged | Identify the defective cable and replace the cable. |
3. If garbled information is transferred (CNC gives parity error or some other alarm):
| POSSIBLE PROBLEMS | SOLUTIONS |
| Baud rate mismatched | Edit the baud rate in the Com Setup window to match the baud rate setup at the CNC. |
| Wrong type of tape code used | Edit the format (ASCII or EIA) in the Com Setup window to match the type of tape code. |
| Defective switchbox | Replace switchbox. |
4. If can only send or receive files (not both):
| POSSIBLE PROBLEMS | SOLUTIONS |
| Cable with wrong wiring | Identify the defective cable and follow wiring instructions to re-wire the cable. |
| Cable is damaged | Identify the defective cable and replace the cable. |
| COM port is damaged | Try COM2 instead of COM1 |
| Modem / COM port IRQ conflict | Change IRQ (Interrupt Request) on your computer (communications port). |
5. If only part of a file is transmitted (file transmission is interrupted):
| POSSIBLE PROBLEMS | SOLUTIONS |
| Machine time-out or overflowed | Option A: Increase the baud rate in the Com
Setup window and make similar changes at CNC. Option B: Break the tape into 2 tapes and transmit separately. Option C: Switch from 3-wire (software handshake) to 5-wire (hardware handshake) |
| Modem / COM port IRQ conflict | Change IRQ (Interrupt Request) on your computer (communications port). |
HOW TO IDENTIFY DEFECTIVE HARDWARE
If the Guidelines for troubleshooting suggest you need to identify a defective component, follow these steps:
1. Make the connection between computer and CNC as simple as possible (remove switchboxes if applicable).
2. Test communication by sending and receiving files.
3. If problem disappeared, start adding the components removed in step 1, one at a time followed by a test of the communication. Once the problem comes back, replace the last component added.
4. If problem persists, replace each component with another one (Make sure that the new component added works fine). Test communication after each replacement.
Note that there could be more than one defective component in the system, especially if a lightning strike or voltage overload is suspected.