Siemens S7-300

Hi,

I have a serial device server, it is a transparant media converter from RS232 to Ethernet.
Now is my question can you use this with Siemens PLC's.
How can you download your program to a Siemens PLC, RS232, MPI???

Best Regards
De volder Marc

Hello,

What kind of siemens plc's or yoy refering to S5 or S7? Seeing you're
talking about MPI I think You mean S7-300 or S7-400?

Normaly you download your program via the MPI port but other connections or also possible.

Give a little bit more info so we can provide you with a little bit more information.

Rudi

Is the converter intended to install on the serial port on a PC ?
If so, I cannot imagine a setup where such a converter would be feasible to get access to an S7 PLC.

If the converter is intended to be installed on an ethernet port on a PC or a switch, to provide a virtual serial port, then I could imagine it being used in connection with a Siemens "PC adapter". This allows you to connect to the MPI port on the PLC from a remote PC on the ethernet network.

Unless your PLC has an ethernet port onboard or via a CP, then you will have to fork out the dough for some hardware that speaks "MPI" or "Profibus".
I recommend the Siemens USB adapter as the cheapest way to get online.
Come back with the specifics if you need help for some other option to get online with S7.

Jesper,

This is not a technical comment. I'm just very, very impressed by your idiomatic command of English when it come to phrases like "fork out the dough". Excellent! A newcomer to English first has to comprehend the link between 'dough' and money, and then understand the use of 'forking out' (an agricultural or gardening fork, not a dining fork - very different implements!) But then, why would anyone ever want to use a fork to handle dough in that fashion? How does anyone ever learn to understand English? You can appreciate poor old Dandrade's problems!

Well done

Ken

Thanks Ken.

Maybe the explanation for picking up such odd phrases can be found in the fact that Hollywood media is so dominant, and that we only use subtitles on TV and movies in this country.

Hi,

Indeed the converter is intended to be installed on an ethernet port on a PC or a switch, to provide a virtual serial port, so you can use a locale PC to connect with the PLC over the Internet?

Will this work with a siemens S7-300 or not?

Thx

It should work.
You will need a Siemens PC adapter (serial to MPI converter) to attach to the ethernet/serial converter.

I have to comment that it is not the most potent online connection.
This because of the bottleneck of the serial connection (38400 baud) between the Ethernet link and the MPI network.

A much better alternative is the Ethernet to MPI/DP converter from either IBH or MHJ.
(they call the same thing "IBHLINK" and "MHJ-NetLink" respectively. I dont know who is the original manufacturer).
This converter will give you the fastest online connection.

Hi,
Can you use the profibus connection on the PLC?
I'm not sure but Profibus is a RS485 bus or not?
And the converter is transparant, so it don't change the protocol?
Could this work?

Thx
marc

MPI and Profibus are exactly the same electrically speaking (*).
Both the PC adapter and the mentioned Ethernet adapter(s) will work on Profibus.

Obviously there has to be a Profibus port on the CPU.

*: Most noticable difference is that an MPI segment with an S7-300 in it is limited to 187.5 kBaud and 50 meters.

edit:

And the converter is transparant, so it don't change the protocol?

Click to expand...

Electrically, the converter is transparant, it is a means to connect to the Siemens PC adapter. The PC adapter can work on Profibus as well, but it definitely switches protocol in order to do it.

edit again:
It sounds like you are new to Siemens, MPI and Profibus.
First, MPI and Profibus are both RS485 networks.
Second, in STEP7, use the Set PG/PC interface utility to add a PC adapter as the online interface. Play around with the settings to see what is possible. Notice that you have to specify a COM port where the PC adapter is attached. That would be the virtual COM port of your Ethernet-to-Serial converter.