Dear Experts,

I am currently designing a Profibus-FO architecture with S7-415H and Optical Link Module. After gone through few rounds of the manual, I still cant decide whether the architecture I have in mind is possible.

Please refer attachment of my architecture, and educate me on the possibility.

*Note: Please ignore the single Profibus DP line and OLM, as I'm trying to simplify the drawing.

*Update: Updated new drawing for clearer picture.

Have a nice day

Thank you

Hi,

imho this configuration is not possible. You are not allowed to have two masters on one Profibus system.

I think you have to duplicate all the OLM and fiber optic lines and use two IM modules in each ET200.

Then from the left 400H you go via one OLM line to all of the left IM of ET200 and from the right 400H via the second OLM line to the right IM of the ET200M

Regards
Myst

Hello,

Just a suggestion here.
you use a redundant CPU.
To avoid that the Profibus network being a single point of failure, you could implement a redundant Profibus network (one per CPU of the 400H) and ET200M equipped with two IM153.
Like the drawing in annex.

 Hi Myst,

Foremost, thanks for your input.

My apologies, the drawing here is extremely simplified. In actual deployment, there would be one OLM for each Profibus DP from CPU, then two IM153 on ET200M rack. (Total of two OLMs).

So they are working as a fault-tolerant Profibus DP master as per S7-400H architecture.

Regards

Thank you

Myst

Hi,

imho this configuration is not possible. You are not allowed to have two masters on one Profibus system.

I think you have to duplicate all the OLM and fiber optic lines and use two IM modules in each ET200.

Then from the left 400H you go via one OLM line to all of the left IM of ET200 and from the right 400H via the second OLM line to the right IM of the ET200M

Regards
Myst

 Hi there!

Thanks for the suggestion, that was the intended design here.

My main concern here is, can the OLM works in such star topology. Where the Profibus DP master sits in the middle (Star topology), instead of the common "end device" methodology.

Also, in Star topology, can the Profibus DP (electrical) multidrops to further ET200M I/O rack?

jklm

Hello,

Just a suggestion here.
you use a redundant CPU.
To avoid that the Profibus network being a single point of failure, you could implement a redundant Profibus network (one per CPU of the 400H) and ET200M equipped with two IM153.
Like the drawing in annex.

Hi wsrekz,

OLM is electrical to FO converter not switch. So it won't work in start topology. 

U will need to connect all ET200 in multidrop. 

Also u can use another Profibus port of CPU to connect the load on right side.

Hi,

 Dear All,

            I think the system architecture which is explain in image will work fine.

           Please refer fallowing link:

https://support.industry.siemens.com/cs/ww/en/view/59884186

Thanks 

Hi All,

I have gone through the OLM BA document earlier, it does claim that Star topology could work.

However, the curious part here is that am I allow to do a further multidrop out of the star topology? Since the architecture involves few IO rack, instead of one.

Thank you all.

Hi,

     Yes it will work with multi-drop network after.  

      Please find attached image for working system architecture.

Regards,

Mahesh Nakade