Same help with an assignment

Hi to all

I have an assignement in PlC of SIEMENS
I search through the net and i discover this forum
I have some questions to ask
1)What are the protocols of communication of PLC?
2)What are their charateristics?
3)How are they connect?
4)The use of a plc network in association with other devices
thank you ina dvance

Please tell us what you think the answers to these questions are, and what you have done to find this information.

This group will be willing to help you, if you show us that you have given the assignment some thought. We will not do your homework for you, however.

RG

i find out that some of the protocols that aare used are ethernet,DH+,RS282.
i search at siemens.com.
i have download the manuals of S7-200 and S7-300.most of the are connected through the paraller socket.
i dont want to make the assignment for me.I just want some extra information
I cannot find the characteristics of the protocols for the plc
thank you

First off, I've never heard of RS282 (although I'm quite prepared to be informed to the contrary) I think what you mean is RS232.

I don't know the 7-200 at all, but the S7-300 CPU certainly doesn't have a parallel socket (in the PC sense, at least), although there may be a CP module which offers paralle I/O (probably pretty old though.

Try doing a general searvh on the internet for "fieldbus systems" then go back to the Siemens Support site and search for the bus systems you've turned up.

You'll also get some useful info (perhaps too much) if you search for "communications systems" in the Siemens support site.