connecting Siemens S7 via Moxa convertor

Hi, I am *not* a involved in programming PLCs in any way. I do IT support for a factory where a couple of the guys maintain the PLCs and I support them.

They mostly use siemens controllers for everything. They don't have any sort of a network connected up. Instead they take a laptop to the machines, or bring the siemens controllers to their lab and program them there. They do this using either the Siemens Simatic S7 PC-USB adaptor or equivalents like the Systeme Helmholz Netlink USB compact

We've got winxp virtualized using Virtualbox to support the older Siemens packages which have been happily working without issues until last week when the USB device mapping stopped working and I haven't been able to get it to reliably work again since.

So, I would like to cut out the usb adaptor and switch to IP. I.e:

virtual winxp <--IP-->moxa adaptor <--RS422->Siematic S7-300

but I don't know how the siemens stuff works. The Siemens profibus interface seems to be a DB9 RS422 interface. It should be possible to connect this to a Moxa converter to allow us to connect via IP. However, I don't know what options should be configured for this to work with, say, a Siemens Siematic S7-300, nor which pinouts should be used to do the interconnect. i.e DCE or DTE pinout config? Are these 2-wire or 4-wire for rx/tx?

I've spent quite some time trawling through online docs without any luck. Almost all the info online is geared to programming these - perfectly reasonable really, but not what I'm looking for.

Has anyone done this? Can you point me in the direction of a doc or page which summarizes whats what. I'm familiar with Sync and Async comms, what I don't know is what should work with the siemens tools and their PLCs.

Thanks in advance.

Ian

There are S7 programming adapters available, which have Ethernet on one side instead of USB. You can use them for programming S7 plcs via MPI or Profibus, easy to use just like the USB adapters.

Netlink Pro also from Helmholz:
https://www.helmholz.de/prod.d,80_92_93.html?p_id=142

duh, that was kind of stupid of me. I should have just looked there. Thats probably going to be the quickest solution. Thanks

However, do you know of a guide to connecting-things-up with profibus or modbus? I'm interested in finding out more - but I'm not interested in the programming plc side. Just the systems/networking bit. I'd like to propose getting this plant a bit more up to date but I need to know how this stuff works, whats required and what can be done.

The problem I'm finding is that everyone wants to sell their solution which does everything, when all I want to do is make things more like the IT world. I'm sure the info is out there and I'm just asking the wrong questions or haven't found the right place yet. I only found this site today for example.

If you are using mostly profibus, System Helmholz makes a profi->ethernet adapter thats called a netlink pro.

We have a few of these in my plant and they work pretty well. I cant recommend any others because these are the only that I've dealt with.

If you have a large number of machines on a profibus network, you can install one netlink pro to get all the machines online, and wirelessly accessible.

You won't find a general answer to all possible Profibus questions, as there are many varieties of Profibus networks out there (Profibus DP, Profibus PA, Profibus FMS, ...). What you can do depends on the network setup, and at least of the capabilities of the components you are using.

I think for a IT guy the Wikipedia article should be a good starting point to get information about the basics, the underlying physical network (RS-485) and so on. If you want to go deep into the details, you should read the page from Max Felser which is linked on the english wikipedia page. Also Siemens has lots of documents about Profibus networks.

The same for modbus. But in the Siemens field, Modbus is not a very often used protocol.

why you don't install newer step7 5.5 version to laptop? it runs on win7 32 and 64 systems and usb adapter works then.

+1 on the Netlink Pro

Thanks for all the responses. Strangely I only recieved email alerts for the first two messages. They purchased the netlink pro and I got it set up yesterday - only took and few minutes and everything is working.

As to why not install step 7 5.5? I have no idea. They have a mess of different packages from siemens, each of which is used to configure/program different devices... and this doesn't include the older step 5 stuff. The interfaces vary wildly in their style and usability from tool to tool without any consistent terminology used.
Honestly siemens programming tools seem like a complete mess to me. Maybe its just lack of familiarity. I need to find out more about how all this stuff works.