need to read siemens S7 I/O in labview through Modbus/TCP

[jprk]

Hi friends,

    We are developing a industrial project and facing a scenario in networking as follows...

Brief abt Project

        Its a sweage treament plant. We are using NI-PAC and  Labview version : 8.5.1 for process control. We got some 3rd party I/O that has to be monitior in Labview.

Details of 3rd party

    - Siemens S7 - 200 with EM 277

In our plant the whole network is through FO - TCP/IP. Now,we need to take Siemens I/O through TCP/IP into labview. How effectively this can be done.If that has to be done with Profibus/Modbus converter can we do that configuration online without distrubing plant. 

Thanks & regards

Pravin Jayapaul

Systems Engineer

[Charlie_P]

Good Morning Pravin,

I think that LabVIEW's TCP/IP VIs will be a good solution for your application; there are many examples of TCP/IP VIs in the LabVIEW Example Finder.

LabVIEW can also communicate over Modbus (Ethernet or serial) via the Modbus Library (free) or the DSC Module (easier).  You should not need to disturb the plant in order to configure your software.

[jprk]

Hi charlie,

    Thanks for yur reply, but my question is :

- Siemens PLC S7 - 200 with EM 277 profibus DP is used.

- Our network is ethernet TCP/IP.

So first i hv to make this profibus to talk with my network which is TCP/IP,  then with labview tools as u said i can read I/O's.

Hope my question is clear if not please let me know

Thnaks & Regards

Pravin Jayapaul

Systems Engineer

[Charlie_P]

Good Evening Pravin,

I still do not understand what your question is.  What are you trying to accomplish in LabVIEW?  What hardware do you have? How are the different pieces of hardware connected to one another and the network?

[jprk]

Hi charlie,

     How u doing,oops!!! regret for the inconvenience. iam attaching our network plan(rough diagram), hope this will help you to understand better.

       In that diagram, you could see we have diferent control rooms (MCC) each are in different location and all are more than 100 mts away from SCADA room and all the process is control by NI-PAC with labview 8.5. Some equipment control in different MCC's are done by there PLC (siemens) and the status we need to monitor in Labview .Now my question is wat will be the best way to interface these PLC's with labview to monitor with quality and cost effective.

[Charlie_P]

Good Afternoon Pravin,

Thank you for the image; I think I am starting to understand your system.

It seems that you are in need of an OPC Server.  There are many out there but we offer NI OPC Server.

Supported Device & Driver Plug-in List for NI-OPC Server

     https://www.ni.com/en/support/documentation/supplemental/07/supported-device---driver-plug-in-list-f...

You can use an OPC Server with LabVIEW, via datasockets.  However, you may want to look into the LabVIEW Datalogging and Supervisory Control Module.  LabVIEW DSC is the ideal tool for your high-channel count and distributed applications. It offers data management tools; such as easy-to-use I/O configuration, automatic datalogging, full alarm management and event logging, and real-time and historical trending. Also, with easy networking, including a networked real-time database for distributed logging, built-in security, and OPC connectivity, LabVIEW DSC provides tremendous ease of use to get your large-channel count system up and running quickly.

LabVIEW Datalogging and Supervisory Control Module

     https://www.ni.com/en-us/shop/product/labview-datalogging-and-supervisory-control-module.html

I see the red Profibus blocks on the diagram; it seems that this element can be left out entirely.  The control rooms (MCCs) are already connected to the network via TCP/IP.  What is the use of Profibus in this application?  Is it needed?  Is it planned for all of the MCCs to have this connection to the main FO backbone, or just the two shown?

[jprk]

Hi charlie,

     Hope u doing great, first i thank you very much for your support and reply. Yes we need that profibus coz the I/O' from the 3rd party comes through this. The 3rd party control panel is different panel in the MCC room for some machinery control we need to just to take that I/O in labview to monitor the status, sorry in that diagram its show together and not all control room going to hv profibus but only three. If you going to suggest OPC server do we need Profibus interface card also. We hv given proposal to hv a profibus to modbus tcp/ip gateway for this issue.wat will be your suggestion.

thanks

Pravin

[Charlie_P]

Good Morning Pravin,

The following forum thread seems to be very similar to the Profibus portion of your application.

Profibus Serial interface NI OPC server

     https://forums.ni.com/t5/Industrial-Communications/Profibus-Serial-interface-NI-OPC-server/m-p/52429...

If your Profibus hardware is already connected to your PLC (the PLC can access the same information you want LabVIEW to access), you can probably access the appropriate information through the PLC, over whichever connection you make to your PLC.

[unclebump]

You might be able to use a hardware solution and skip the opc server step.

http://www.prosoft-technology.com/layout/set/print/content/view/full/7475

[effgee · Accepted solution]

Hi Pravin

I'm not certain from your diagram exactly what your network is. You have shown some connection from the FO-tcp-ip to the S7-200. How does this happen ? Or is that what you are asking here, to work out the options ?

SInce the S7-200 can only be a profibus DP slave thru the 277, it won't "see" any of the other profibus IO anyway. You could use a Siemens CP243 module to give the S7-200 tcp-ip connectivity. Also, if there is a profibus connection from the S7-300 to the S7-200, all the IO of the S7-200 can be mapped onto the S7-300, so you only need to worry about communicating with the S7-300.

Another option

Regarding modbus, siemens they charge lots of money for the Step7 modbus library. On the other hand, the S7-200 comes with a free modbus library, but it is serial modbus RS485, not modbus tcp-ip. Maybe you could use this, and use of one of the many serial-to-ethernet gateways available.

-Michael