You are not registered yet. Please click here to register!


 
 
plc storereviewsdownloads
This board is for PLC Related Q&A ONLY. Please DON'T use it for advertising, etc.
 
Try our online PLC Simulator- FREE.  Click here now to try it.

---------->>>>>Get FREE PLC Programming Tips

New Here? Please read this important info!!!


Go Back   PLCS.net - Interactive Q & A > PLCS.net - Interactive Q & A > LIVE PLC Questions And Answers

PLC training tools sale

Reply
 
Thread Tools Display Modes
Old July 13th, 2005, 12:49 PM   #1
daveswerld
Member
United States

daveswerld is offline
 
Join Date: Apr 2005
Location: Charleston SC
Posts: 18
Question Siemens S5 and S7 Dual Masters for Profibus

Hi all. I am in the process of converting as existing S5 948 PLC to a S7-416 processor for the expanded IO. In doing so, but maintaining everything running as much as possible, I am going to transfer controls to the S7 in blocks, primarily based on the IO racks that can be moved.

Apparently, multiple profibus masters can exist on the same physical profibus network. I have the S5 assigned as master <1> and the S7 assigned as master <5>. Once I put both PLC's on the same network, one or the other crashes (bus faults, PLC QVC faults, and bus faults on the cards). It seems that which ever PLC was the last one on the network gets the IO. The controls function properly if the S5 is on the bus alone. Connecting the S7 allows the IO to continue functioning, but generates a fault (EXTF and DP1) on the S7. Disconnecting the S5 at the 308C causes the S7 faults to clear, but IO is locked up (no code called yet in S7). The only way to get controls and IO functions back is to disconnect the DP from the S7 and reconnect the S5.

I am obviously confused here as to how multiple masters work. The service and support site has been less than helpful, and Johnson City will call back.

Any Ideas?
Thanks
  Reply With Quote
Old July 13th, 2005, 05:18 PM   #2
Amr Hassan
Member
Egypt

Amr Hassan is offline
 
Join Date: May 2005
Posts: 340
as far as i know , only one master can acess the ET 200 interface modules
  Reply With Quote
Old July 14th, 2005, 02:16 AM   #3
RheinhardtP
Lifetime Supporting Member + Moderator
Australia

RheinhardtP is offline
 
RheinhardtP's Avatar
 
Join Date: Oct 2004
Location: Perth
Posts: 560
Newspaper From Siemens Help file

In this configuration, input data from intelligent DP slaves or simple DP slaves can be read directly by the master of a different DP master system on the same physical PROFIBUS-DP subnet.


In a configuration for direct data exchange (lateral communication), local input address areas of an intelligent DP slave or of a DP master are assigned to the input address areas of a PROFIBUS-DP partner.


The intelligent DP slave or the DP master uses these assigned input address areas to receive the input data that the PROFIBUS-DP partner sends to its DP master


Starting Configuration
Double-click the DP interface of the configured receiver (DP master or already configured I slave).
  1. Select the "Configuration" tab.
  2. To create new line in order to configure direct data exchange, click the "New" button.
  3. In the dialog that appears, select "DX" mode and assign the input address areas to each other (you can find more information in the online help for this dialog).
    Mode: "DX" for direct data exchange, ("MS" for master-slave)
  • Partner DP Addr.: PROFIBUS address of the DP partner
  • Partner Addr.: Address of the logically assigned address area (sender)
  • Local Addr.: Address of the logically assigned address area (receiver)
Hope this helps, just check in your siemens Help, they have nice schematics which might help.

regards

Rheinhardt
__________________
“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?”

― Albert Einstein

www.tier16.com
  Reply With Quote
Old July 14th, 2005, 09:13 AM   #4
JesperMP
Lifetime Supporting Member + Moderator
Denmark

JesperMP is offline
 
JesperMP's Avatar
 
Join Date: Feb 2003
Location: Copenhagen.
Posts: 13,179
When there are multiple masters in a Profibus network, then each master must be aware of the other masters and slaves assigned to the other masters.
The important detail is that the Token Rotation Time must be calculated, and that is only possible if all nodes are known in the project.

In STEP7 you can make an integrated project with all the masters and slaves. Then STEP7 will automatically calculate the Token Rotation Time. Bad thing is, it only works with S7 masters.

As you have an S5 master, then you have to tell the S7 master manually about the other nodes.
I think (I am not in front of a STEP7 PC at the moment) that you can do it in the Hardware Config. Open the Properties for the Profibus network in question and then open the Bus Parameters (or Bus Profile ?), you should specify a "User defined" bus profile. Dig a little further (under "Properties" or "Settings" maybe), and you will find a place where you can specify other Profibus nodes, Masters or Slaves, that must be included in the calculation of the Token Rotation Time.

The above is for the S7 master.
Something similar must be done for the S5 master. Unfortunately, I have no experience in COM PROFIBUS or whatever you are using to configure the IM308C.
__________________
Jesper
3 strikes and you're out
  Reply With Quote
Old July 14th, 2005, 10:09 AM   #5
JesperMP
Lifetime Supporting Member + Moderator
Denmark

JesperMP is offline
 
JesperMP's Avatar
 
Join Date: Feb 2003
Location: Copenhagen.
Posts: 13,179
Oh by the way,
I assumed that you know that you can not assign the SAME slaves to BOTH maters.
However, your "It seems that which ever PLC was the last one on the network gets the IO" makes me think that you are trying to let both masters access the same slave i/o. That wont work.

Only one master can access a slave.

When you add a slave to the S7 master, you must remove it from the S5 master.
__________________
Jesper
3 strikes and you're out
  Reply With Quote
Old July 14th, 2005, 10:40 AM   #6
daveswerld
Member
United States

daveswerld is offline
 
Join Date: Apr 2005
Location: Charleston SC
Posts: 18
Quote:

Oh by the way,
I assumed that you know that you can not assign the SAME slaves to BOTH maters.
However, your "It seems that which ever PLC was the last one on the network gets the IO" makes me think that you are trying to let both masters access the same slave i/o. That wont work.

Got that one covered. There is one ET200U drop that is designated for the S7, on the profibus, and not addressed by the S5 at all.

In looking at what was done before this, there were 2 308C's in the S5, on 2 separate profibus legs. I combined these to get to one single L2 to allow the drops to be combined and moved. Before this was started, the S7 actually shared the l2 and picked up the drop it was supposed to. While they shared the profibus through a repeater, the 308C and the S7 did share the same network, without configuring the opposite PLC in either hardware config.

I have been through the configs on both to see if an address was repeated, and the only thing I can find is that the S7 was listed as master <1>, as was the single 308C. That was why I changed it.

Unfortunately, I lost my window to experiment with the S5, as it is still controlling the process. I will have to try these changes next week when they shutdown.
  Reply With Quote
Old July 14th, 2005, 10:52 AM   #7
JesperMP
Lifetime Supporting Member + Moderator
Denmark

JesperMP is offline
 
JesperMP's Avatar
 
Join Date: Feb 2003
Location: Copenhagen.
Posts: 13,179
Quote:
While they shared the profibus through a repeater, the 308C and the S7 did share the same network, without configuring the opposite PLC in either hardware config.
Sometimes, Profibus will continue to work without configuring the other nodes. This is because the limit value, "Target Token Rotation Time", is so much bigger than the "Typical Token Rotation Time". In other words, some "slack" is accounted for so that the system is not so sensitive. But doing so is a bit of a gamble. If the Token Rotation Time exceeds the Target Token Rotation Time then the bus will fault.

Quote:
In looking at what was done before this, there were 2 308C's in the S5, on 2 separate profibus legs. I combined these to get to one single L2 to allow the drops to be combined and moved. Before this was started, the S7 actually shared the l2 and picked up the drop it was supposed to. While they shared the profibus through a repeater, the 308C and the S7 did share the same network, without configuring the opposite PLC in either hardware config.
I am a little confused now. Can you specify precisely what it is that doesnt work now, but worked before ?
__________________
Jesper
3 strikes and you're out
  Reply With Quote
Old July 14th, 2005, 11:07 AM   #8
daveswerld
Member
United States

daveswerld is offline
 
Join Date: Apr 2005
Location: Charleston SC
Posts: 18
As you can tell, I am still confused here. Before we shut down, the S7 had drop 68 on it,connected through the profibus, with no faults on either the s5 or the s7. The S5 actually had 2 308C's and 2 profibus cables. The S7 was attached to one of the profibus cables, that went to 308-2. The 2 comprofibus config's were combined to allow for a single profibus connection. One of the 308's was removed from the S5, and on start up was when I started having these bizarre issues going on.

One of the things that was changed when I made the single flash card was changing the baud rate for the S5. It was originally 19.2 on one and 187.5 on the other, and now they are all 187.5 (on single 308). In reading through all of these replies (thanks folks) I am wondering if the higher baud rate is causing a timeout on the profibus. I will likely change the baud rate on the next opportunity.
  Reply With Quote
Old July 15th, 2005, 04:14 AM   #9
vignesh
Member
India

vignesh is offline
 
Join Date: Jul 2005
Location: coimbatore
Posts: 2
hi all

can any body tell me which plc is best for communication
  Reply With Quote
Old July 15th, 2005, 08:51 AM   #10
JesperMP
Lifetime Supporting Member + Moderator
Denmark

JesperMP is offline
 
JesperMP's Avatar
 
Join Date: Feb 2003
Location: Copenhagen.
Posts: 13,179
So the problems started when the two Profibus networks were combined into one, not when the S7 was added to the second network ?

That Profibus network #1 was set to 19.2 kBaud is a bit odd. This speed is only used for very long distances.
That you are getting errors when running it at 187.5 kBaud could mean that the network really needs the slow speed to work.
You should investigate why the network was set to this speed.

You may consider to add a second Profibus port to the S7.
You can then retain the two networks at 19.2 and 187.5 kBaud.
__________________
Jesper
3 strikes and you're out
  Reply With Quote
Old July 20th, 2005, 02:51 PM   #11
daveswerld
Member
United States

daveswerld is offline
 
Join Date: Apr 2005
Location: Charleston SC
Posts: 18
I am looking into what I have to do to get back to the configuration that I had previously. The repeaters were combined when the 308's were combined, so it will take a little work.

As far as the S7, it has a DP port and a DP/MPI port that is configurable. That will allow the 2 profibus lines to go to it. I am still confused about the timing that is being affected, but I know that the original S5 at 19.2 was set that way because of some very long profibus runs that have been in place for a while now. That leads to some slow updates on remote IO, but hopefully will go away with the convert to S7.
  Reply With Quote
Old July 21st, 2005, 07:28 AM   #12
JesperMP
Lifetime Supporting Member + Moderator
Denmark

JesperMP is offline
 
JesperMP's Avatar
 
Join Date: Feb 2003
Location: Copenhagen.
Posts: 13,179
Quote:
I am still confused about the timing that is being affected, but I know that the original S5 at 19.2 was set that way because of some very long profibus runs that have been in place for a while now. That leads to some slow updates on remote IO, but hopefully will go away with the convert to S7
You cannot circumvent this limitation by converting to S7.
One way is to place repeaters strategically along the slow Profibus line. Then you can bump up the speed to 187.5 kBaud, and maybe even combine everything into one network.
__________________
Jesper
3 strikes and you're out
  Reply With Quote
Old April 13th, 2007, 05:25 PM   #13
AlbertSacda
Member
Canada

AlbertSacda is offline
 
Join Date: Apr 2007
Location: bc
Posts: 6
Plc S5 To S7

Originally Posted by AlbertSacda
Hi
I have PLC S5 115uU and I try to use CPU S7 414 and S5 I/O rack. When I converter S5 program , i find some eroor for FB 12 ( FIFO ) and Fb 250 ( Read Analog input ) and FB 251 ( Write to analog Output).
Could you help me how can fixed these errors.
My email: albertras@gmail.com

Thanks
Albert



Quote:
Originally Posted by daveswerld
Hi all. I am in the process of converting as existing S5 948 PLC to a S7-416 processor for the expanded IO. In doing so, but maintaining everything running as much as possible, I am going to transfer controls to the S7 in blocks, primarily based on the IO racks that can be moved.

Apparently, multiple profibus masters can exist on the same physical profibus network. I have the S5 assigned as master <1> and the S7 assigned as master <5>. Once I put both PLC's on the same network, one or the other crashes (bus faults, PLC QVC faults, and bus faults on the cards). It seems that which ever PLC was the last one on the network gets the IO. The controls function properly if the S5 is on the bus alone. Connecting the S7 allows the IO to continue functioning, but generates a fault (EXTF and DP1) on the S7. Disconnecting the S5 at the 308C causes the S7 faults to clear, but IO is locked up (no code called yet in S7). The only way to get controls and IO functions back is to disconnect the DP from the S7 and reconnect the S5.

I am obviously confused here as to how multiple masters work. The service and support site has been less than helpful, and Johnson City will call back.

Any Ideas?
Thanks
  Reply With Quote
Old April 13th, 2007, 09:39 PM   #14
JesperMP
Lifetime Supporting Member + Moderator
Denmark

JesperMP is offline
 
JesperMP's Avatar
 
Join Date: Feb 2003
Location: Copenhagen.
Posts: 13,179
Hi Albert.

Next time, start a new thread. Your problem has nothing to do with Daves problem.
edit: And I see that you have posted the same in several other threads. This is very bad form Albert !

Anyway, when you use the automatic converter from S5 to S7 you must expect some manual work. If you only have the mentioned problems then you are in luck.
For the FIFO block, look at FC92 in the Standard Library under S5-S7 Converting blocks.
For the scaling functions, look at FC105 and FC106 in the Standard Library under TI-S7 Converting Blocks.
__________________
Jesper
3 strikes and you're out

Last edited by JesperMP; April 13th, 2007 at 10:18 PM.
  Reply With Quote
Old December 15th, 2008, 06:47 PM   #15
gkelley@mcaps-inc.co
Member
United States

gkelley@mcaps-inc.co is offline
 
gkelley@mcaps-inc.co's Avatar
 
Join Date: Dec 2008
Location: Houston
Posts: 86
Dave,
this is a very complicated problem everyone would like to have a solution to. Vipa has an S5 PLC in a new format. It is small like the S7200 but it takes the s5 program without any problems as long as you have only I/O modules and not IP's, FM's, or other intelligent modules.
  Reply With Quote
Reply
Jump to Live PLC Question and Answer Forum

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Topics
Thread Thread Starter Forum Replies Last Post
Siemens S5 -> S7 Conversion mirror_untrue LIVE PLC Questions And Answers 7 December 17th, 2008 04:40 PM
Siemens S5 and S7 Key Disks sectoreng01 LIVE PLC Questions And Answers 47 November 25th, 2008 01:56 AM
siemens s5 + s7 on ethernet want acess each plc program via modem dbolton LIVE PLC Questions And Answers 2 October 8th, 2004 01:40 AM
Siemens S5 & S7 Balls Ache LIVE PLC Questions And Answers 3 December 29th, 2002 06:32 AM
profibus network between Siemens S5 and S7 PLC Leonardo LIVE PLC Questions And Answers 3 June 25th, 2002 09:05 AM


All times are GMT -5. The time now is 08:06 PM.


.