5/25/2011 5:23 PM | |
Posts: 947 Rating: (45) |
I like ET200S. It has good set of functional modules, is more maintainable in the breakdown of a single entry. Modules are replaced quickly. Can be hot replaced ()hot-swap). For the H-system I'm using Y-Link. For my system it is enough. Splitted from what s benefit of using s7 400 IO cards instead of s7 300 IO cards?. |
Last edited by: O_Moderator at: 5/31/2011 8:42 AMnew subject after splitting |
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5/27/2011 6:16 AM | |
Joined: 10/7/2005 Last visit: 9/22/2024 Posts: 3021 Rating: (1054)
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Hello Aret not too sure why you dislike the Y-link, butcan tell you that your assumption concerning the internal workings of it is not quite correct. What the Y-Link does is to create a new "underlying" DP Master network which is independent of the higher level redundant DP Master system (see also "How is the Y-Link structured" for more). If you wish, you could even setthe underlying DP Master baudrate (and/or other DP related Parameters) to any value that you wish irrespective of the settings for the higher level redundant DP Master system. The tranfser of databetween the underlying IM197 based DP Master system and the higher level redundant IM153-2's DP takes place at the speed of the underlying DP Master (ok, this is an assumption on my behalf and I can't verify this at the moment). I wonder if your assumption comes from the fact that a Y-Link is initially "dragged" into the HWconfig from the"DP/PA link" catalogue as well as the generalfunctionality of a DP/PA link. If aDP/PA link is used,the underlying "PA" systemdoes infact run at a fixedspeedof"only" 45.45 kbps on the backplane(to whichthe IM157 PA couplers are connected). This is ok though as PA is fixed to run at31.25 kbps, the PA couplers do no more (and no less) than convert the 45.45kbps RS485 backplane DP signal to a 31.25 kbps MBP (Manchester bus powered)PA signal. |
Last edited by: fritz at: 5/27/2011 6:18 AMfixed link Cheers |
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5/28/2011 9:20 AM | |
Joined: 5/24/2007 Last visit: 4/24/2024 Posts: 284 Rating: (27) |
Hi Aret Have a look at the following link. http://support.automation.siemens.com/WW/view/en/43688632 Also at the documentation for Y-Link in that link. The restriction for the I/Os come from the IM153-2 which handles only 244byte I/O Frame. Krish |
5/28/2011 2:20 PM | |
Joined: 10/7/2005 Last visit: 9/22/2024 Posts: 3021 Rating: (1054)
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Just to be clear, the 244 Byte "restriction" is a limit that is NOT IM153-2 or Siemens imposed. Instead, it is simply the maximum amount of cyclic I/O data that a DP Slave can have asperProfibus Standard. |
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5/28/2011 4:43 PM | |
Joined: 10/7/2005 Last visit: 9/22/2024 Posts: 3021 Rating: (1054)
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No need to be sorry Krishas I was actually agreeing with you. I merely wanted to clarify that the 244 Byte limit is a general Profibus DP Slave limit rather than a Siemens imposed limit for the Y-Link (andan IM153-2 is a Profibus DP Slave irrespective if used as an ET200M I/O station, or DP/PA link or Y-link). |
Cheers |
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5/28/2011 7:39 PM | |
Posts: 947 Rating: (45) |
Hi the 244 Byte "restriction" is a limit that is NOT IM153-2 , this islimit (restriction) ASIC SPC3. |
5/29/2011 2:39 AM | |
Joined: 7/2/2008 Last visit: 8/26/2024 Posts: 928 Rating: (308)
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Hello Everyone, Although I really hate to write 2 consecutive posts but I think it's better giving a chance for moderators to split posts regarding ET200S & Y-link in a new thread beside I didn't like to write a very long boring single post.
My experience with ET200Sunder Y-Link was not so good. To make it hot swappable, I had to modify the original DPV0 GSD file and for sure Siemens didn't support this solution.It's working but I don't recommend it.
Sometimes the ET200Scan violate the 256slots limit before violating the 244I/O bytes. I must admit and we allmay admit that we sometimes use the Y-Link in a way that's not designed for. Siemens tells, if you want I/Os go for S7-400 or ET200M modules. If you have drives or devices with single DP port, go for Y-Link. I know about Aret's case and I think it's a special case having a big number of slaves with 244 bytes like power meters. Maybe in such case it's better to work with Ethernet based devices (power meters).
Good idea. In this case it would belike redundant I/O - one sided DParchitecture. You may not select a DP-slave but write somethingsimilar to the RedundantI/O library to select the healthy input and write to the 2 outputs. I don't have a clue but I think this is correct. It's limited to the back plane bus capability which is the 187.5 KB/s. Best regards. H-H |
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5/29/2011 4:19 PM | |
Joined: 10/7/2005 Last visit: 9/22/2024 Posts: 3021 Rating: (1054)
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Dear all I won't exclude the possibility that this is the case, but would be quite suprised if it is, since it would create a bottleneck and seriously comprimise the update time of the Y-Links underlying DP Slaves. Let's go back to the workings of a DP/PA link to start outlining whyI think the Y-Link does NOT use the 187.5 kbps MPI K-bus of the backplane for the data trnasfer between the IM153-2's and IM197: A Profibus DP 45.45 kbps bus exists on the backplanewhich is used as a commmon bus for all attached PA couplers (the bottom two pins of the backplane bus carry this signal with the B line being the bottom pin. Attachinganother U-shaped backplane connector the the last PA coupler on the DP/PA link allows youto measure the signal). This is also quite logical as a standalone PA coupler (directly connected to a DP network via its DB9 connector), requires you to operate the DP Network at 45.45 kbps. As for the Y-link: I would (as before)assume that the link between the (redundant) IM153-2's and IM197 operates at the speed of the underlying DP network (default is 1.5 Mbpsbut this can be changed). I also beliefthat this underlying DP network linksback to the IM153-2's via the bottom two pins of the backplane. Alterantively though, the IM153-2's do perhaps usethe high speed I/O bus (P-bus) as the link to the IM197 (I can't see though how this explains that Node 1, 2 and 125 are visible and indicated as DP Masters on the underlying DP network, which is also the case for a DP/PA link when the PA network is checked with a bus analyser). Anyway, it would be interesting to find out for sure, so the questions is: Who has a spare S7-400H and Y-link lying around to do some tests on (or who has perhaps done the tests already and can enlighten us all)? |
Cheers |
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5/30/2011 8:59 AM | |
Joined: 10/7/2005 Last visit: 9/22/2024 Posts: 3021 Rating: (1054)
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Good point Aret and valid question. As you said though, it would in your example require two Profibus scans of the H-system DP Master to get/update all the Y-links underlying DP Slaves values. It would also require that Siemens adds (and test and document) this additionalfunctionality to the Y-Link which will then cause users to need/buy less of them (i.e. this improvement of the Y-Link is unlikely to happen). |
Last edited by: fritz at: 5/30/2011 9:03 AMCheers |
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9/28/2014 11:19 PM | |
Posts: 3 Rating: (0) |
Thanks for the infromation that yo provide could you please upload the Modified GSD |
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