Hi,
And hello to all my old friends at control.com.
You may, or may not remember that I am somewhat of an S7-200 fan, so I wanted to keep you all up to date on the new Siemens S7-1200 PLCs which will be available in the next 6-8 weeks. The press releases are available on the 'net iat

http://www.s7-1200.eu

Siemens have shown some production units at Hanover and are preparing 'starter kits' for general release. They have promised that I can have one to play with and I'll let you know what they're actually like!!

The s7-200 range will still be actively produced and supported until 2011.

The biggest difference is that the connectivity is PROFINET as standard, and serial connections are available as add-ons to the left of the CPU. The PROFINET will give access to Remote IO and PLC-PLC comms. The CPU is faster and more memory is available, and can be assigned as program or data storage.

The programming of the S7-1200 range will eventually be integrated into Step 7, although initially STEP7-basic will be available to cover the first CPUs and the related new touch panels, (many of which are LINUX based).

The CPUs have flash firmware which will allow upgrades which I'm told will include a web server and access to web service.

I'll let you know what they're actually like!!

Marc Sinclair
http://www.germainesystems.eu

 

What is the instruction set like? Is is based on the existing S7-200, or is this just the S7-300 instruction set in a new package? If it's the latter then the "real" S7-200 is a dead product line, which will disappoint quite a few people.

"More memory" has to be taken with a grain of salt. If they have changed the instruction set or the implementation of it then they may have needed to add a lot more memory just to keep existing capabilities. For example, it takes a lot more instructions (and more memory) to do something with an S7-300 than it does to do the same application with an S7-200.

Also, does the Profinet comms actually allow you to control I/O, or is the S7-1200 just a passive slave device on the network? I was told a few years ago by someone at Siemens that they wouldn't provide a Profibus Master module for the S7-200 because it would cut into sales of the higher priced S7-300.

As for the web server, what can it do? Just static pages? Does it embed some Java applets like the existing modules? Does it allow some real server side scripting?

A "web service" implies an http based protocol. What is it? It's not a real "web service" if it's actually just some embedded Java (or ActiveX/DotNet) applets that run in the browser and talk through a binary protocol (which is what the existing modules do).

I'm a bit skeptical at the moment as to whether they offer a real web service. A real web service protocol could be reverse engineered to let people talk directly to the PLC without going through a Siemens controlled software gateway. This is something that Siemens has been very reluctant to offer for some years now (although they didn't always feel that way).

I'm not too surprised that Siemens has come out with something new. Their entire existing PLC product line has started to look a bit long in the tooth.

 

Hello Marc;
Thanks for the updtate.
I can't wait to see what the software will look like, what the instruction list will cover, see if FCs/FBs from the S7-300 range have been integrated...
Probably will look into one of the early training kits to test one to shreds.
Regards,
Daniel Chartier

 

The S5 is long since obsolete, yet Spares and support are still available. I believe that the s7-200 will still be actively supported for at least three years and then it will enter the 'non design' phase, so still far from being a dead product. The software will be Step7 basic and will allow the programming of the PLCs and the associated screens.

The S7-200 and S7-300 series have been converging for some time, I've used the IEC option in MicroWin since it was available and so for me the changes will be minimal.

The S7-200 has enough memory for its class, but the s7-1200 has so much more IO and connectivity potential that extra memory is a must.

The release versions will be able to take advantage of remote IO via the PROFINET port.

>I was told a few years ago by someone at Siemens that they wouldn't
provide a PROFIBUS Master module for the S7-200 because it would cut into sales of the higher priced S7-300.

More likely there wasn't enough demand, I could probably have used a dozen at most

>As for the web server, what can it do? Does it allow some real server side scripting?

I don't know! The Siemens guys are really excited and are aware that the upgradeable firmware will allow them to add features, a web server being one of the first. Being able to make simple HTTP GET/POST requests will allow data storage on remote databases, and limited web services have been mentioned.

>I'm not too surprised that Siemens has come out with something new. Their entire existing PLC product line has started to look a bit long in the tooth.

I must admit that I was a little worried that the s7-1200 might be a marketing exercise, but it does look like a serious attempt to raise the bar for the low end PLC.

Marc Sinclair
http://www.germainesystems.eu

 

I believe the market for a Profibus master for the S7-200 would have been talking to things like RF systems, single axis servo drives, and process monitors (e.g. press force monitors). A lot of small assembly machines don't need a very big PLC, but they do need to interface to that sort of equipment. You could have used the serial port on the S7-216 for one of them, but if you needed to combine several of them in one machine there was no good solution.

The Siemens guy told me he could have sold lots of S7-200s with Profibus in that market, but customers ended up using a more expensive S7-300 just for the interfacing options (which I suppose was why Siemens did this). Of course, some customers simply used a different brand of PLC, which is what this guy was unhappy about.

If the S7-1200 has a Profinet master, then that changes a lot of things in that market. Although that still leaves the problem that there aren't a lot of Profinet devices for a PLC to talk to.

As for web service, yes you're right. If you can do GET/POST with XML or JSON documents, then you can do a REST type web service. The big question then is how fast the web server will be. If it's fast enough, then this is good enough for getting data out of the PLC. The problem will be if you need to poll several times per second. I suspect that their software will bog down at that rate.

 

I've seen some screen shots and it looks fairly standard, They are insisting on calling it an engineering system, so I hope it isn't too dumbed down. As far as integration between screens and PLCs go, anything will be an improvement on the current S7-200 / Micro/Win TP177/WinCC Flex Micro setup. I'm expecting IEC and world date handling, the rest I'm sure I'll get used to.

Marc Sinclair

 

I have just "played" with the TIA software for the S7-1200 and found it very easy to use although a bit slow. It is very similar to the Wincc Flex software that I am used to.

I understand that SCL and STL programming languages will be added later and that Step 7 (for 300 & 400's) will be in this TIA format as well? Nice piece of software from Siemens, shame they could not do something about the Logo software!!

 

STL wont be added to Step 7 only SCL will be added in 2010. It will be released in the Professional version. And not in the Basic version.

The professional version will support the 300 and 400 PLC series.

And the TIA portal looks and handles really great but you need an update to system to run it smoothly.

 

There will be no STL, just SCL S7-200 will be supported till 2012.

 

These look pretty cool from what little information I've seen. Looking forward to getting my hands on one.

 

I've spent some project time working with one of these. I really like the way that Step 7 Basic has a similar feel and architecture as Simatic Manager.

In case this is useful to some of you who are just starting, I've posted some of the things I've learned so far...

<b>"Indirect Addressing" in Step 7 Basic v10.5 SP2:</b>
http://www.dmcinfo.com/blog.aspx/ar...rect-Addressing-in-Step-7-Basic-v105-SP2.aspx

<b>Siemens S7-1200 PLC communicates through Sinaut MD720-3 cellular modem:</b>
http://www.dmcinfo.com/blog.aspx/ar...es-through-Sinaut-MD720-3-cellular-modem.aspx

More to come... Enjoy!

Nick
Project Engineer
DMC, Inc.
EXPERT ENGINEERING & SOFTWARE SERVICES
www.dmcinfo.com

 

Hi,

Even though it's been a while since S7-1200 has been launched, my experience says several users - especially 'Siemens partners' seem to be still at dark on the actual "positioning" as well as "capabilities" of this product. They are more comfortable in deciding on S7-300 if the 200 can't do the job.

Specifically I have realized the following recently the hard way - after Siemens sold me S7-1200s to upgrade S7-226 systems.

i) even the Local I/O capability of 1200 seems less than what the 200 could handle -

ii) the added memory which was the reason for upgrade doesn't exist in reality as the s7-1200 instruction set consumed most of this even without for the same application which I ran in s7-200 (less than 16 k)

iii) I needed to change the HMI hardware and introduce an Ethernet switch since

iv) and after developing the application Siemens discovered that the 1200 can support only 2k f retentive memory.

All in all Siemens has managed to establish that the 200 is a better product - at least for my application.

Is the retentive memory really limited to 2k?
I feel there should be ways of overcoming this.
And being 'data' can we not have an option of storing this on non-volatile media - to get it load on every power up ?

Would like your comments guyzz..

Gee.

> I've spent some project time working with one of these. I really like the way that Step 7 Basic has a similar feel and architecture as Simatic Manager.

> In case this is useful to some of you who are just starting, I've posted some of the things I've learned so far...

> <b> "Indirect Addressing" in Step 7 Basic v10.5 SP2:</b>
> http://www.dmcinfo.com/blog.aspx/ar...rect-Addressing-in-Step-7-Basic-v105-SP2.aspx

> <b> Siemens S7-1200 PLC communicates through Sinaut MD720-3 cellular modem:</b>
> http://www.dmcinfo.com/blog.aspx/ar...es-through-Sinaut-MD720-3-cellular-modem.aspx