Skip to Content

Register Login

Industry Online Support

Technical Forum

Navigation

problem when communication fails

Created by: diogo.obpa at: 10/20/2008 11:29 AM (7 Replies)

Rating (0)

Thanks 0

8 Entries

10/20/2008 11:29 AM	Rate (0)
diogo.obpa Posts: 48 Rating: (0)	Hi everyone ! I've got a project with 2 plc's 315-2pn/dp. They are communicating in Profibusthrough s7-connection and I'm using the blocks put and get to exchange the information. The problemoccurs when one of the plc's goes down, for instance, for a power fault, the communication is of course lost. But when the plc's gets powered up again, the communication link cannot be established again. In order to do that I've got to switch power off of both plc's and power them up again to re-establish the link. My question is, how can the communication link be automatically re-established once the link has been broken ? Thanks for your help, Diogo Aguiar
diogo.obpa Posts: 48 Rating: (0)	Last edited by: diogo.obpa at: 10/20/2008 11:32 AM
Suggestion To thank Quote Answer

10/21/2008 2:36 PM	Rate (0)
J_Bell Posts: 5822 Rating: (412)	Hello, would you mind telling us how you configured your S7 Connection... over PROFIBUS? I am a bit surprised, because I thought only Industrial Ethernet would work with S7 Communication at the S7 300 integrated interfaces. About the reestablishment of the S7-Connection I would like to ask how long did you wait until you switched off the PLC, was it longer than... lets say... 3 to 5 minutes? Best regards J_Bell
J_Bell Posts: 5822 Rating: (412)
Suggestion To thank Quote Answer

10/22/2008 10:59 AM	Rate (0)
diogo.obpa Posts: 48 Rating: (0)	Hi Bell ! I didn't explain myself very well...the two plc's have each one one profibus network to communicate with their stations and the plc's communicate each other by ethernet through an s7-connection...sorry for my mistake in the previous post. regarding your question, the time doesn't matter really much...it can be 5 hours, 5 seconds or 5 days...the problem is always the same...once one of the plc's is powered down by any kind of reason, the communication can only be re-established when both plc's are powered up again... is there any way to re-establish the communication without having to do the power down/power up trick ? thanks, Diogo
diogo.obpa Posts: 48 Rating: (0)	Last edited by: diogo.obpa at: 10/22/2008 11:04 AM Last edited by: diogo.obpa at: 10/22/2008 11:00 AM
Suggestion To thank Quote Answer

10/23/2008 12:40 PM	Rate (0)
J_Bell Posts: 5822 Rating: (412)	Dear Diogo, I am sorry.... Well, I tried it myself with two CPUs with PN Interfaces. They are of the latest version.. I have to admit. I used two S7 Connections with PUT / GET from each side. It works perfectly If I switch one PLC down or disconnect one from the Network the Connection breaks down. Then, after a while I reconnect both and the Link and the Communication is back on again. As I do not know how you communicate, if you use BSEND / BRECV or PUT / GET I am not sure if I made the right type of communication. As well I do not know if you use the latest versions of the Firmware and how you start or continue your Communication so I wonder if you would explain a bit more what you do and how. Best regards J_Bell
J_Bell Posts: 5822 Rating: (412)
Suggestion To thank Quote Answer

10/23/2008 1:27 PM	Rate (0)
diogo.obpa Posts: 48 Rating: (0)	hi bell ´ thanks again for your reply. the firmware is the same in both PLC's and is version v2.6.5 is the same as yours ? the problem occured twice in the same customer...one of the PLC went down for a power fault...when powered up again the communication could not be re-established until the other PLC was powered down and then up...can you please send the test project you've created so i can test it and compare with mine ? thanks in advanced, Diogo
diogo.obpa Posts: 48 Rating: (0)	Last edited by: diogo.obpa at: 10/23/2008 1:30 PM
Suggestion To thank Quote Answer

10/23/2008 1:44 PM	Rate (0)
J_Bell Posts: 5822 Rating: (412)	Hello, well, I have two CPUs of the version 2.6.7 running. I add my really little sample for you here. Best regards J_Bell Attachment S7_pn_co.zip (272 Downloads)
J_Bell Posts: 5822 Rating: (412)
Suggestion To thank Quote Answer

10/23/2008 5:24 PM	Rate (0)
diogo.obpa Posts: 48 Rating: (0)	thanks j_bell i'll try your project and i'll give feedback just a question how can i upload my firmware to v2.6.7 ? thanks once again Diogo
diogo.obpa Posts: 48 Rating: (0)
Suggestion To thank Quote Answer

10/24/2008 12:27 AM	Rate (0)
J_Bell Posts: 5822 Rating: (412)	Hi, how about this Download: Operating System Updates for CPU 315-2 PN/DP also available for the other PN CPUs of the S7-300. Best regards J_Bell
J_Bell Posts: 5822 Rating: (412)
Suggestion To thank Quote Answer

|

Share this page:

Share this page on...

Follow us on