6-1
PROFIBUS Optical Bus Terminal (OBT)
C79000-G8976-C122-02
Troubleshooting
Table 6-1
LED Display
Possible Cause of Problem
L+ 24V LED not lit
- Power outage
- OBT defective
L+ 24V LED flashing
- The transmission rate could not be set
CH1 LED not lit
- Break on one or more wires of the RS-485 LAN cable
- Wires A and B of the RS-485 LAN able connected to wrong terminals
- Attached PROFIBUS node is defective or not sending
- PROFIBUS node not attached or attached node is not turned on
CH1 LED lit
But PROFIBUS nodes signa-
ling bus problems
- Wires A and B of the RS-485 LAN able connected to wrong terminals
- Short-circuit on the RS-485 LAN cable
- Break on one of the wires of the RS-485 LAN cable and wires A and B con-
nected to wrong terminals
- No or wrong termination
CH2, CH3 LED not lit
- Send and receive FO cords swapped over
- Break on FO cord receiving receiving from partner module
- No partner module connected or partner module is not turned on
- Attached partner module is defective (not sending)
CH2, CH3 LED lit
But PROFIBUS nodes signa-
ling bus problems
- FO connector is loose
- FO cable distance to next module too long
- Receive FO cord interrupted and disturbance caused by extraneous light
If none of the LEDs indicates a problem and you still encounter communication
problems (for example no confirmation, unexpected frames), check the monitoring
times set on the PROFIBUS nodes (such as the Slot Time).
For more detailed information on these parameter settings, refer to the description
of your PROFIBUS DTEs and the configuration software.
6
Summary of Contents for SIMATIC NET PROFIBUS
Page 10: ...Contents viii PROFIBUS Networks SIMATIC NET 6GK1970 5CA20 0AA1 Release 2 05 2000 ...
Page 11: ...PROFIBUS NETWORKS 1 ...
Page 26: ...PROFIBUS NETWORKS 1 16 PROFIBUS Networks SIMATIC NET 6GK1970 5CA20 0AA1 Release 2 05 2000 ...
Page 241: ...A 1 PROFIBUS Networks SIMATIC NET 6GK1970 5CA20 0AA1 Release 2 05 2000 Testing PROFIBUS A ...
Page 254: ...Testing PROFIBUS A 14 PROFIBUS Networks SIMATIC NET 6GK1970 5CA20 0AA1 Release 2 05 2000 ...
Page 288: ...Installing LAN Cables C 26 PROFIBUS Networks SIMATIC NET 6GK1970 5CA20 0AA1 Release 2 05 2000 ...
Page 325: ...F 1 PROFIBUS Networks SIMATIC NET 6GK1970 5CA20 0AA1 Release 2 05 2000 Dimension Drawings F ...
Page 338: ...Dimension Drawings F 14 PROFIBUS Networks SIMATIC NET 6GK1970 5CA20 0AA1 Release 2 05 2000 ...
Page 396: ...Infrared Link Modul ILM 6ZB530 3AC30 0BA1 54 Copyright by Siemens ...
Page 434: ......
Page 438: ...Contents ii PROFIBUS Optical Bus Terminal OBT C79000 G8976 C122 02 Contents ...
Page 450: ...Network Topology 4 4 PROFIBUS Optical Bus Terminal OBT C79000 G8976 C122 02 ...
Page 458: ...Installation and Startup 5 8 PROFIBUS Optical Bus Terminal OBT C79000 G8976 C122 02 ...
Page 460: ...Troubleshooting 6 2 PROFIBUS Optical Bus Terminal OBT C79000 G8976 C122 02 ...
Page 464: ...Technical Specifications 7 4 PROFIBUS Optical Bus Terminal OBT C79000 G8976 C122 02 ...
Page 468: ...References 9 2 PROFIBUS Optical Bus Terminal OBT C79000 G8976 C122 02 ...
Page 470: ...Abbreviations 10 2 PROFIBUS Optical Bus Terminal OBT C79000 G8976 C122 02 ...
Page 478: ...References I 4 PROFIBUS Networks SIMATIC NET 6GK1970 5CA20 0AA1 Release 2 05 2000 ...
Page 488: ...Glossary Glossary 8 PROFIBUS Networks SIMATIC NET 6GK1970 5CA20 0AA1 Release 2 05 2000 ...