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DP-DP coupler

Created by: himanshu at: 7/24/2009 9:02 AM (6 Replies)

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7/24/2009 9:02 AM	Rate (0)
himanshu Posts: 37 Rating: (0)	Hi Iam using DP-DP Coupler for communication between S7-400 & S7-300 CPU. CPU 315-2DP. MLFB - 315-2AG10-0AB0. CPU 400-- 6ES7-414-3XM05-0AB0. Can MPI port of 300 CPU be connected to DP-Dp Coupler? . If it would have to be connected on DP port then how to do programming ofCPU 300?.i want to do programming through Ethernet port of S7-400 CPU.pls see the attachedautomation configuration Attachment DP DP Coupler.zip (286 Downloads)
himanshu Posts: 37 Rating: (0)
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7/24/2009 8:43 PM	Rate (0)
Bhaskaran Posts: 107 Rating: (13)	himanshu Hi Iam using DP-DP Coupler for communication between S7-400 & S7-300 CPU. CPU 315-2DP. MLFB - 315-2AG10-0AB0. CPU 400-- 6ES7-414-3XM05-0AB0. Can MPI port of 300 CPU be connected to DP-Dp Coupler? . If it would have to be connected on DP port then how to do programming ofCPU 300?.i want to do programming through Ethernet port of S7-400 CPU.pls see the attachedautomation configuration Hi Himanshu, I could not open the excel file you have placed with your question. The S7 300 does not allow the MPI port to be configured as DP port but S7 400 does. You will always see in hardware configuration with S7 400 CPU'S the port is mentioned as MPI/DP. You can use it as you wish. So connecting a MPI port of S7 300 to DP DP coupler is out of question. As far as the S7 400 is concerned you have a MPI port which can be configured as a DP port, a seperate DP port and a Profinet port which you intende to use for programming. What exactly you want to do with the DP DP coupler?? Is it a question of just isolating 2 Profibus networks with a bit of data exchange ??? If you just want to exchange small amount of data between the 2 controllers without worrying about isolation of networks then why don't you go for Global Data communication over MPI. You will also save a DP DP coupler and it is also simple. The other option is you can connect the available DP port of both the PLC's to the coupler. In both the cases you can use the MPI port of 300 CPU for programming. Last but not the least with DP DP coupler you can transfer data just as digital io's with inputs and outputs but with Global Data communication you can transfer limited amount of data from DB's ,Flags, IO's etc. I hope it helps
Bhaskaran Posts: 107 Rating: (13)
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7/27/2009 8:40 AM	Rate (0)
himanshu Posts: 37 Rating: (0)	Hi, Actually i want to communicateCPU 315-2 DP(315-2AG10-0AB0) with CPU 414- 3DP(414-3XM05-0AB0) over MPI link. i have topass data of 120 words from 300 to 400 cpu . 10 words of data from 400 to 300 cpu. what can be possible way. please help me with any project if there. Regards Himanshu
himanshu Posts: 37 Rating: (0)
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7/27/2009 9:07 AM

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dchartier

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Hello himanshu;
Have a look at the following FAQ, it discusses MPI connections and data exchanges. It also provides links to sample configurations so you can develop your application as per your requirements.
http://support.automation.siemens.com/WW/view/en/21537047

Hope this helps,
Daniel Chartier

Edit, after examining your Excel file:
One more point:
You cannot use OLMs with MPI in order to extend the length of the network.
http://support.automation.siemens.com/WW/view/en/8574670
You can use a repeater (and copper cable)for that purpose, but only up to 50 m (on standard S7-300 MPI ports):
http://support.automation.siemens.com/WW/view/en/37627

Also: for your “ET S7-300” units, which I presume are ET 200M interface modules with S7-300 SMs, there is an IM 153-2 FO module that would allow you to connect your Profibus-DP FO directly, without an additional OLM:

6ES7153-2BB00-0XB0

SIMATIC DP, ET 200M INTERFACE IM 153-2 FO HIGH FEATURE FOR MAX. 8 S7-300 MODULES, WITH REDUNDANCY, W. INTEGR. FO INTERFACE FOR CONFIGURING AN OPTICAL LINE

Regards, DC

Last edited by: dchartier at: 7/27/2009 9:35 AM

Last edited by: dchartier at: 7/27/2009 9:34 AM

8/5/2009 11:36 AM	Rate (0)
himanshu Posts: 37 Rating: (0)	I could possibly transfer data with MPI Port between 400 CPU & 300 CPU with help of SFC 67 & SFC 68. FO Connection is there between MPI link of both CPU. But the data transfer is somewhat slow. how to improve response .Please help me what input to be given in REQ & CONT inp of SFC 67 & SFC 68, whether fix or variable. In my project i had given permanent HIGH input to REQ and permanently LOW input to CONT input. Please see attachment. Attachment SFC 67&68.pdf (249 Downloads)
himanshu Posts: 37 Rating: (0)
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8/5/2009 3:05 PM	Rate (0)
umencho Diamond Expert Joined: 3/21/2006 Last visit: 1/14/2025 Posts: 10239 Rating: (1182)	Hello, About REQ and CONT look for example at atachment. At REQ - A positive level located at the some bit starts reading, and CONT - False - Dismantle the connection after the end of the data transmission. So attachment is for SFC67 but the same logic you can use with SFC68. ABout to increase the speed is possible with increasing the speed of MPI network. But this depends from what kind of CPU do you use. You can find more details about possible MPI baud rate at technical specification for current CPU. Hope this will helps. Best regards, Hristo Mihalev Attachment untitled.JPG (243 Downloads)
	Last edited by: UMENCHO at: 8/5/2009 3:07 PM
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8/5/2009 5:27 PM	Rate (2)
J_Bell Posts: 5822 Rating: (412)	Dear Daniel, I am sorry for my late reply but I think it is maybe worth it to start the discussion here. I see and understand the point you mentioned about the OLM use with MPI. But in this case I have to disagree with this FAQ. In my opinion MPI is properly useable with OLM PROFIBUS too. The only reason for restricting the use of OLM with MPI is that it is not possible to set the Retry Limit of MPI to 3. Well, this is really the only cause. What is this parameter for. The parameter Retry Limit explains how often a Telegram might be send because of a drop out of data within the PROFIBUS. This parameter is only than needed if the redundant optical OLM Ring has been split to a line and will be reconnected. During this period it might be that telegrams will be destroyed and may be needed to be resend more often than once. Such situations happen with PROFIBUS DP systems more often... but with MPI? I doubt that this happens especially if you use X_PUT/X_GET maybe once a second. Well... I just wanted to mention this here. On the other hand I agree with you, the use of DP/DP Coupler with MPI is not recommendable at all. The only way to go is S7-Basic Communication with X_PUT / X_GET on the S7-300 and PUT / GET on the S7-400. Best regards J_Bell
J_Bell Posts: 5822 Rating: (412)
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