4. Troubleshooting (PROFIBUS DP)
♦ Causes of Error
Possible Cause |
| Examination Method | Countermeasure |
{ Disconnected | (1) | Check that terminating | Fix the problem. |
terminating |
| resistors are connected to both |
|
resistors |
| ends of the network. | How to find the trouble |
{ Cable | (2) | Measure resistance between | point: |
disconnection |
| signal wires with device | Remove the terminating |
{ Disconnected |
| power supply OFF. | resistor on one end of the |
connector | → Normal: 100 to 120 Ω | network. The trouble point | |
{ Disconnected | z Measuring point: Connection of | is where resistance changes | |
signal wire | the trouble unit | from 220 Ω. | |
| z For detail, refer to the section |
| |
| 4.2.3.1 Connection Problem. |
| |
{ Loose connector | Check for the connection of | Connect the connectors and | |
{ Loose signal wire | connectors and signal wires. | signal wires again. | |
| → The connectors and signal |
| |
| wires should be firmly |
| |
| connected. |
| |
| z Checkpoint: all stations and all |
| |
| branch taps |
| |
| z For details, refer to the section |
| |
| 4.2.3.2 Loose Connector and |
| |
| Signal Wire. |
| |
{ Broken unit | Replace the trouble unit with a | Replace the unit with a | |
| new one. | new one. | |
| → Verify whether the problem is |
| |
| fixed. |
| |
z No cause is | Identify the trouble point by |
| |
identified. | dividing the network. |
| |
| → For details, refer to the section |
| |
| 4.2.3.4 Broken Unit |
| |
| Examination. |
| |
Fieldbus I/O Rev.6 | 129 |
