Skip to Content

Register Login

Industry Online Support

Technical Forum

Navigation

Device fault on ProfibusDP stops PLC with BusFailure

Created by: Triodes at: 8/30/2006 4:07 PM (4 Replies)

Rating (3)

Thanks 0

5 Entries

8/30/2006 4:07 PM	Rate (0)
Triodes Posts: 20 Rating: (1)	Hi, I have a Profibus DP network with S7-313-2DP and 3x MM420 attached. They respond to commands etc but when one goes into failure (breakers tripped), the PLC goes to Stop mode with the BF and SF failure lights on. Is there a way to configure the profibus network so that the rest of the system stays operational when one device goes off-line? We have several MM420's but also devices that perform a controlled reboot and drop off of the DP network for a minute or so. This all causes the CPU to stop. Thank you.
Triodes Posts: 20 Rating: (1)	Last edited by: Triodes at: 8/30/2006 4:09 PM
Suggestion To thank Quote Answer

8/30/2006 6:58 PM	Rate (2)
SteveA Posts: 297 Rating: (41)	You can look at the Diagnostic Buffer using Step 7 to see exactly what caused the Stop, but in general, you need to have OB blocks 82, 85, 86, and 122 in your program to avoid stops due to bus faults. You do not have to actually do anything inthese blocks, but if they are not loaded and an event occurrs which calls them, the CPU halts. SteveA
SteveA Posts: 297 Rating: (41)
Suggestion To thank Quote Answer

8/31/2006 12:12 AM	Rate (1)
Late Platinum Expert Joined: 1/7/2006 Last visit: 11/17/2023 Posts: 2705 Rating: (318)	Hi Triodes, When you use Report System Error then the blocks are programmed by STEP7. Configuration of "Report system errors" and display in STEP 7 V5.1 There are also FB's and FC's programmed by Siemens that give you direct the missing station. PROFIBUS DP Diagnostics Blocks FB125, FC125 for SIMATIC S7 Good luck with this software... [;)]
	I hope that the answer will help, if you have still questions, don't hesitate to ask me. All the best, Late Never say never, think in solutions, not in trouble......
Suggestion To thank Quote Answer

8/31/2006 11:34 AM	Rate (0)
Triodes Posts: 20 Rating: (1)	Hello, OB122 was the missing link. I set the error settings like you said, this installed OB82/85/86, but did not solve the problem. I manually made OB122 (completely empty) and now the CPU does not stop. The BF and SF are reset automatically when the DP device comes back online. Thank you both VERY much!!!!!
Triodes Posts: 20 Rating: (1)
Suggestion To thank Quote Answer

9/1/2006 12:20 AM	Rate (0)
Late Platinum Expert Joined: 1/7/2006 Last visit: 11/17/2023 Posts: 2705 Rating: (318)	Hi Triodes, No thx, Iám happy I canhelp you... [:D]
	I hope that the answer will help, if you have still questions, don't hesitate to ask me. All the best, Late Never say never, think in solutions, not in trouble......
Suggestion To thank Quote Answer

|

Share this page:

Share this page on...

Follow us on