Hello,

please tell me

1-how Ethernet to fiber optical module works.(i dont know its model/company)

its installed here with modicon PLC to communicate with switches.

2-if we want to communicate s7-300 with modicon cpu 651 then which cards we have to use to make compatible s7-300 communication with modicon.

please guide me as i am newbie with automation.

Thanks

Hello ahmed;

If what you want is basic information on how conversion from Ethernet copper wiring to fiber-optic is carried out, you could look for this small article from Wikipedia (with many interesting links), or search for different media converter manufacturers such as Black Box, B&B Electronics, Moxa, Perle...

https://en.wikipedia.org/wiki/Fiber_media_converter

Remember that one of the specific parameters you must take care of when selecting a media converter is the type (or mode) of optical communication cable that you will use: single-mode or multimode.Check this out in technical articles if you knowledge is not up to date;for example:

http://www.beldencables-emea.com/en/products/cable_basics/fiber-optic-cable/index.phtml

Now, communication interfaces between a Modicon PLC and a S7-300 PLC will depend on the protocol selected.

Modicon generally support Modbus/TCP natively, so if you decide to use Modbus/TCP as the exchange protocol you will need to implement the Open Modbus/TCP libraries (from Siemens) either on a CP 343-1 Ethernet processor or on the integrated Profinet interface of a _PN CPU.

You can have an introduction on the subject in this link, or you can open the Simatic Modbus/TCP Conference of this forum to see previous discussions on the subject (have a look at the Product Conferences at the left of this page):

Siemens Open Modbus/TCP

One of the difficulties when using Modbus (or Modbus/TCP) is that all addressing must be done in terms of Modicon datatypes, even in the Siemens PLC. That is you must associate internal DB addresses wit the Modbus communication areas. Please make sure you study this in the Open Modbuys/TCP documents you follow.

Hope this helps,

Daniel Chartier