Need help on Profibus-DP

[raul_vaze]

We have around 140 MOV connected on profibus-DP in a ring topology(typical distance is around 1.5 kms) . These MOV will be connected to Schneider module 140 CRP-811 which is quantum module for Profibus connectivity . In the data sheet of that module it is written to supprt a max of 126 devices(32 max/node) . Can anybody pls help as to how can i connect these devices to the module

 

[PLC]

Use two modules and put 70 on each one.
Dont forget to use repeaters.

 

[raul_vaze]

Use two modules and put 70 on each one.
Dont forget to use repeaters.

But what is the term 32/segment mean . How can i have different segments connected to my profibus card and can i have my CRP-811 card as master and MOV as slave ????

 

[raul_vaze]

Use two modules and put 70 on each one.
Dont forget to use repeaters.

Why do i need a repeater ??? Can i convert profibus to FO and then run it over long distance . Can u pls name some repeaters in market

 

[JesperMP]

And what is a "MOV" ????

 

[raul_vaze]

MOV is a Motorised Operated Valve

 

[JesperMP]

Read chapter 8.2:
http://support.automation.siemens.com/WW/view/en/1971286

Is it 1.5 km between each node, or 1.5 km in total ?

 

[RGB]

Profibus limit is 126 devices per system which is why you'd need two masters. Each segment can only have 32 devices in it, before you need to add a repeater.

 

[raul_vaze]

total distance between CRP module(Schneider module supporting Profibus) and the last MOV(Motorised Operated valve) is around 1.5 km

 

[raul_vaze]

Profibus limit is 126 devices per system which is why you'd need two masters. Each segment can only have 32 devices in it, before you need to add a repeater.

Thanks RGB but does this mean that a single segment can go to support around 70 devices if i add a repeater after every 32 devices . Do u have any information about any site on web that gives me information about the same

 

[Jobbe]

Thanks RGB but does this mean that a single segment can go to support around 70 devices if i add a repeater after every 32 devices .

Some basics:
- A PROFIBUS network can contain 127 PROFIBUS devices
- You can divide the network in segments by using repeaters
- Each segment can contain 32 devices (including the repeaters!)

You can put a maximum of 124 MOV's on one master if you make enough segments, so you need two masters for all your MOV’s. I don’t know that Schneider module, but most PLC’s can have several PROFIBUS networks.

If you want a ring topology you will need to work with a fiber network. Each fiber OLM can be considered as a repeater.