Siemens Networking

I'm quoting a project where the customer wants to use Siemens PLCs. I'll have one master for scheduling, over all coordination, and linking my "sub-system" to a plant wide SCADA. There are three slaves for individual machines that only need to link to the master. Each PLC will have an HMI.

I want to use ladder logic for the programming so I can easily port over logic that works on other platforms. Based on I/O requirements and program complexity (low for both) the S7-200 will do the job, and will also handle my "sub-system" communications network plus my HMI. So far, so good.

However, the customer wants to tie my master to his SCADA and some S7-505's using ethernet, and require the ethernet to comply with IEEE 802.3. According to my Siemens distributor and the Siemens literature, it looks like the only way to do this is to use an S7-300 for my master. I'd rather not do this. The extra hardware cost doesn't bother me, but it looks like the S7-300 is entirely different programming software from the S7-200. (Why do they do things like that???)

So, could you guys look in your collective hats and let me know if you have any rabbits to pull out that will let me tie the S7-200 to the ethernet link. I'm thinking in terms of third party hardware or some kind of bridge that will get the S7 variant of ethernet into Profibus or the MPI protocol.

Thanks,

Tom

Have you looked at the Prolinx Gateways from Prosoft Technologies?
http://www.prolinxgateways.com/products/4204.html

Tom your best shot is to call Siemens Tech Support at 1-800-333-7421, this is in Johnson City, TN. They can give you better options.

I know the S7-200 will work with Profibus and that they make interface modules to connect it to Ethernet, not sure it would be any cheaper though then putting in an S7-300 just to interface the 2 protocols.

As far as why do they do these things, who knows. I know the S7-200 branched off from the TI line of processors, while the S5 & S7-300 are purely Siemens. Technically I aint so sure you couldnt use S7-300 and still accomplish what you want as far as using ladder etc. You would probably be more familiar with the S7-200 style programming though.

Thanks, Jim. Prosoft couldn't help - ditto for SST, CTRLink, and EXOR - my list of "usual suspects".

Ron, thanks for the Johnson city number. I just got off the phone with them, and Siemens will have an ethernet module for the S7-200 "the end of the year". I guess this is probably an exercise in futility unless there is a third party solution out there.

Tom as my previous posts prove I am curious when it comes to Siemens plc's. I am not so sure you couldnt integrate at least one S7-300 just to interface the protocls...ie profibus and ethernet.

I know you said you checked with but did they mention the X-Link?http://www.mysst.com/xlink/content.asp

I know I have seen this done, just cant place when/how. Its hard to remember all this stuff.

I think it's tough to go from ethernet to some other protocol. Sure, you can change physical layers easy enough. But, your PLCs are going to just sit there screaming "can you hear me now???" because the message string is all wrong. You can't go from RS232 to ethernet and back again can you? That might work better.

I think Advantech (you might have their catalog) has a converter with a brain in it: www.advantech.com.
You might also try www.anybus.com

I've never tried any of these converters. I imagine the learing curve is going to be pretty steep.

AK

Here is another 3rd party web site who make ethernet adaptors for the s7 200 range.

http://www.awc-corp.com/Products/Polybus/Polybus_RTU_Products.html

That might help

Paul

Siemens has changed distributors in my area, so I got called on by the new guys. Forgot to ask explicity about this but they left a line card and I noticed DIGI CONNECTWARE

They offer alot of serial to Ethernet options. So far all I have done is glance over the products, but it might be worth looking into.

You mention that the S7-300 software is different than the S7-200.
Is the S7-300 software the same as the S7-505's?
Is there already S7-200's in use at that plant?
From a maintenance point of view the more of the same the better.

From the maintenance department
JCBlanch

Tom, My issue are the following:
1. s7-300 programing software is step7 v5.1, it is much different software to Step5 (for s5 cpu) and microwin v3.1( for s7-200 programming).also, it need authorization key.
2. as I know that , s7-200 can communication with s7-300 use MPI protocol or Profibus, for your project, I sugest you can use Profibus protocol: add a EM277 module at s7-200, and use a s7-315-2-DP cpu as a master, then s7-200 would be slave station, also, you would use a cp343-1 in s7-300 to connect to enthernet.

Stanley Zhou

Thanks to all for your help. I'm going to quote the job per Stanley's suggestion. If I get it, I'll let you all know how it turns out.

Tom (AKA "Lefty")

Tom,

If you are going to go the S7-300 route, take a look at the new 313C-2DP. It's a little cheaper than the 315, plus it's got some integrated I/O, it uses a micro memory card which allows you to store the entire project (including tags, comments, etc.) in the PLC, and I think the processor is a bit faster. Siemens has an updated 315-2DP coming out later this year, but it may be too late for you.

Also, do the machines that are going to get S7-200's need local intelligence, or could you use remote I/O instead? If you can use remote I/O over Profibus, you might be able to save a little money. (I've never priced S7-200 hardware, so it might not save you anything). I have been using Siemens ET200M interface modules which work with standard S7-300 I/O.

Good Luck-

Kevin Hammond

Another option when distributed intelligence is required is using either the IM151CPU or BM147/CPU. Both are remote I/O drops with integrated CPU of the S7-300 range. That way you only need one programming package for all. The BM147/CPU is even IP67 rated so you don't need an enclosure.

Tom,

There are devices available that offer an ethernet port and an RS232 port. If the Siemans controllers you are using have a second RS232 port, then this is a viable option (seeing as you are using one port for an operator interface). You can find them for between $300 to $400 dollars.

No handshakeing would be required, it would be considered a pass through port. There is software required, because there is some setup (IP address)

The device that we market is from a company called Moxa. You can contact them at 732-738-4303. You can view their product information at http://www.moxa.com/product/single_port_serial/nport_express.htm

Hope this will help with your dilema.

Stephen

Thanks, Stephen. This looks like exactly what I wanted.