Skip to Content

Register Login

Industry Online Support

Technical Forum

Navigation

ERR LED of Profibus connector

Created by: E C Edwin at: 10/26/2013 5:44 PM (6 Replies)

Rating (0)

Thanks 2

7 Entries

10/26/2013 5:44 PM	Rate (0)
E C Edwin Posts: 3 Rating: (0)	We are using Siemens Slot Type PLC ( S7 412 ) , with 8 Siemens Nodes and 3 OP 77 Display with Vipa Profibus connector with LED indication. Last termination is done at OP77. at the final Node, in Profibus connector ERR LED is ON and OFF only when the machine is started, but PLC is healthy with RUN mode only. What is the problem, ( as per the VIPA connector Manual, Fault indication of Bus open or Termination not done ), but machine is running fine. What may be the reason ??? Kindly discuss.
E C Edwin Posts: 3 Rating: (0)
Suggestion To thank Quote Answer

10/27/2013 3:51 PM	Rate (0)
IBN-Service Posts: 8946 Rating: (999)	E C Edwin ...Last termination is done at OP77. at the final Node, in Profibus connector ERR LED is ON and OFF only when the machine is started, ... Last plug always need the 5V powersupply for termination - resistors. Make sure, that OP77 is energized also when machine is not started.
IBN-Service Posts: 8946 Rating: (999)	Last edited by: IBN-Service at: 10/27/2013 3:52 PM
Suggestion To thank Quote Answer
This contribution was helpful to 1 thankful Users E C Edwin

10/27/2013 5:09 PM	Rate (0)
Marko Bursic Platinum Member Joined: 9/8/2009 Last visit: 7/17/2023 Posts: 1410 Rating: (153)	I have tried those connectors and only thing I can say is that those LEDs aren't much helpful, like there aren't. I also have a doubt that adding aditional electronics on the line somehow influences the network, since the electronics itself has also a capicatance and for sure distorts signal. But I can say if not all connectors are green, then something is wrong with your network. The protocol itself also repeats telegrams, you can see this in bus configuration, and corrects errors if a response comes within timeout. The problem not necessarly is located near the connector you see the error, a signal may reflect from one part of cable and collide with other signal producing interference or wave node. At that part your equipment will fall off. My recomandation: - Disconnect all connectors, - Cut out the cable wires, where was connection was done before - make for sure the minimal length of section is at least 0.8m as needed from specifications - on VIPA conector case, you will find a pin(spike) for holding the cable secure. Break them all with clamps, this is the mostly problem on that connectors, the spike damages insulation of cable. - remount all connectros on cables Regards

Suggestion To thank Quote Answer
This contribution was helpful to 1 thankful Users E C Edwin

10/27/2013 5:54 PM	Rate (0)
E C Edwin Posts: 3 Rating: (0)	Thanks for your kind response and time. The OP 77 is also communicating with PLC and able to access the setpoin from HMI. Power LED, TX LED & Termination LED is On in Vipa Connector. As per your guidance may re- Wire the profibus cable to amke termination at final node and will update.
E C Edwin Posts: 3 Rating: (0)
Suggestion To thank Quote Answer

10/27/2013 5:54 PM	Rate (0)
E C Edwin Posts: 3 Rating: (0)	Thanks for your kind response and time. PLC is in RUN mode with GREEN LED, only in this VIPA connector the ERR LED Comes ON for around 3 sec and OFF for around 5sec, but in all other no problem. Even in Simatic manger no error is shown at any station. As per your guidance will check and update.
E C Edwin Posts: 3 Rating: (0)
Suggestion To thank Quote Answer

10/28/2013 10:21 AM	Rate (0)
Marko Bursic Platinum Member Joined: 9/8/2009 Last visit: 7/17/2023 Posts: 1410 Rating: (153)	We had problems in profibus network consisting cca. 60 nodes. From time to time certain stations went offline, VIPA connectors also weren't all green, but we didn't pay attention. When problems ocured, we rewired once. Still problems persisted, now we took a professional profibus analyzer. We saw certain anomalies, but we were not able to determine the location. Then we disconnected all stations and we checked cable sections with Siemens cable tester, we have found B signal line had connection to ground. We solved that. Still problems. Then experienced guys using VIPA connectors told us that they break those spikes on metallic case, because they had the sametroubles with them. So we did reweire all stations again, problem solved - all LEDs are green now, before they weren't and the machine was working. The funny and hard to get thing is - the stations that felt off were not in vicinity of the problematic connector, they were far away. Error LEDs were lit on stations where wiring was OK. We could even see the signal voltage drop on analyzer on that stations due to reflected signal from problematic conector, but we were not able to calculate exactly the distance where reflections wee coming from. So, the conclusion is: Not necessarly the problem is located on the connector that blinks an error. Not necessarly this error will stop the machine, because master retries several times before rising the error. Probably the connection will degrade and it will begin to cause troubles.

Suggestion To thank Quote Answer

10/28/2013 10:30 AM	Rate (0)
Ste39 Platinum Member Joined: 1/21/2013 Last visit: 10/23/2024 Posts: 4620 Rating: (708)	Hi E C Edwin, Have you already seen this thread? Profibus connector with led - Siemens Industry Online Support ...

Suggestion To thank Quote Answer

|

Share this page:

Share this page on...

Follow us on