Step 7 And FB

I have just picked up a demo copy of Step 7 V5.3 from Siemens. They do not have a real copy in Ozz that I can buy - has to come in. UNBELIEVABLE!!!!

The price they quoted me for the "basic" edition is also "unbelievable" when one considers it does not do the 200 processor and has no simulator.

However, I am trying to create some FBs without reading the absolutely painfull manual.

Can anyone help? How can I create some FBs from the Step 7 menu?

For some reason when it is running it "mucks up" the windows task bar. Also amazed at the lack of built in functions. I am used to heaps of functions.

Drag and drop is "painfull" - are there function key combinations?

I have not used Siemens for about 8 years but they certainly have their own way of doing things.

The price they quoted me for the "basic" edition is also "unbelievable" when one considers it does not do the 200 processor and has no simulator.

Click to expand...

Can not blame them for that, many PLC manufacturers have different software for different models, very few even have a simulator. The price, overall, is comparable to many.

IF you fully installed it then Simatic should be listed in the MENU when you click start, look there at the S7 manuals for System and Standard Functions.

As you say, Siemens do seem to believe in the saying that what doesn't cost anything isn't worth anything!


However, creating your FB is pretty straightforward. I assume you've created and opened your (new?) project. Once you've got there, expand the directory structure down to the point where sources and blocks S-Ds are visible. Highlight the Blocks S-D and then click on the insert tab in the menu bar. Normally everythingt here will be greyed out except S/ Blocks. Click on this and a further sub-menu opens with all the possible Blocks, including FBs.

Don't forget that with an FB you'll also need to subsequently create an instance DB for it, but this is best done after you've created your FB program with al its associated parameters.

There are loads of built in functions, SFC's and SFB's.

To see them open any block so you are programming and ensure at the top you select View - Overviews and a side window opens. from here (depending on language, i.e ladder, STL, etc) you'll get the instructions you can use, below them are FB's, FC's etc, these are the ones in your project that you can call and below that...... finally Libraries.

Note, the multiple instances in FB's are blocks that you have inserted into the Stat variables. At your stage of learning you wouldn't want to do that anyway, so should be empty.


Open the libraries and there are sub folders of different groups of standard library blocks, select the one you want and drag it across.

All sorts of convertions, comms, diagnostics, etc, etc..


Pressing F1 when your on an object or Library block, or just about anything open the help file on that object.

Hello Bob,

Hope I'm not teaching you how to suck eggs here, but these online (and free - from Siemens!!!) trainers were quite useful when I got involved with some Step7.

http://www2.automation.siemens.com/fea/html_76/down_module.htm

Thank you all - will give it a go. The last time I used Siemens was the very first windows software they produced and it was absolutely horrible. This appears to be much better and I have figured out quite a bit from past experience and digging around.

Fortunately, the client is fully conversant with Siemens, that is all they use, and he will be with me when we commission the job.

Basically, I wish to assemble some alarm routines in FBs so that I can re-use them and the rest will be in ladder. It is a soft transfer generator system. The reason I wish to use FBs is that Siemens do not allow a lot of freedom with multiple outputs in a rung with different contacts in each output line. Cannot build a decent rung - have to use too many rungs. Not used to that.

Siemens do not allow a lot of freedom with multiple outputs in a rung with different contacts in each output line

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Bob, can you expand a bit on what you mean by that. I never use ladder (other than to view something which has grown too big in the Function Block representation), but as I understand it ladder can do 95% of what Function Block can do and in Function block I can add as may outputs in parallel as I want (at least I've not yet hit a limit and must have used at least 10 on occasion).

Unfortunately, I'm on the wrong PC at the moment, so I can't check if this is the 5% difference!

The reason I wish to use FBs is that Siemens do not allow a lot of freedom with multiple outputs in a rung with different contacts in each output line.

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You can definitely have several outputs in a rung. And you can also add additional contacts that are active in each outputs "own" rung.

Like this for example:

 ------||-----------------() 

                |

                |----||--------() 

                |

                |----||--------() 

                |

                |----||---||---() 

edit:
I always have to go back and reedit code bits like the above.
The empty spaces are cut out or takes up too much space.
What do you say Phil ?

edit:
I always have to go back and reedit code bits like the above.
The empty spaces are cut out or takes up too much space.
What do you say Phil ?

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Why don't you use the code function? (Just quote my message then you will see the code function.)

Hi Werner,

as you can see the "code" function doesnt work so well either.
I think that Phil has to check both "code" and "ladder" functions.

By the way.

About that you have to wait for your copy of STEP7 and that it is too expensive:
Bob, you are aware that STEP7 LITE is available as free download, right ?
It costs nothing, and you can have it "immediately" (after a 200MB download).
If STEP7 BASIS is too expensive, and your project is with S7-300 with no "advanced" networking, then LITE could be enouhh for you.

Hi Bob,

I think Siemens have decided to implement a policy of "annoy the software buyers" to get rid of any customer that is not a Siemens fanatic. Either that, or there may be some other reason.

As for the you have been having:
1, talk to you client and see if they let you load up their copy. With Siemens you can run an un-licenced copy in an un-restricted manner, it just shuts down after an hour. Re-starting it you get another hour to work.
2, In the main manager where you can view all the blocks (including OB1 etc), just right click and you can insert an new block. Pick this as FB and there you go. Open it and edit.
3, You will need to set up in, out, static and local variables. The area to do this is in a split window at the top of the editing page. this is often hidden, so you may have to "drag" it down.

Thank you Jesper - that is exactly what I want to do with outputs. A Siemens representative told me I could not do that. May have misunderstood what I meant.

With respect to Step 7 Lite, I will have an Ethernet interface for the programming computer and then for the client's Citect SCADA. There is also a previously discussed Modbus module on DP. I do not know if Lite will handle this. The processor is a 318 by the way. Will Lite handle this and is there any limitation on the time frame when running etc? I have installed Step 7 basic demo which, I have been told by Siemens, will run ininhibited for 45 days until the "real" software arrives.

I will probably stick to ladder as the program will not be too large and is really pretty simple stuff. Ladder is easier to monitor generally and I only use function blocks for really repetative stuff - do not often come across that.

Doug, the local guys here is Sydney have really been pretty helpful. I used about $180,000.00 AU of Omron PLCs last year and I am just a one man band with a few subbies I use for panels and site work - we have worked together for about 15 years now and know exactly what the other hand is doing. Siemens are aware of my usage and where my preferences lie and have even offered FREE TRAINING!! That has to be a first. But they tell me they have very little to play with as far as software prices go - a bit like AB having to buy their software from Rockwell I guess.
I will buy the software anyway as the client looks like having quite a bit more work for me in the future. I just find it puzzling that Step 7 will not do the 200 - however. I was quite interested in the 200, if the price is right, for some of my jobs. Looks like the Omron CJ1M will probably remain as my PLC of choice due to good software, inexpensive software (NC, screen, simulator, Device Net configurator, Profibus configurator, Serial protocol networking etc etc included for about 20% less than Step 7 and does all current PLCs), 64 bit cards, inexpensive serial cards with free protocols etc.

BobB said:

With respect to Step 7 Lite, I will have an Ethernet interface for the programming computer and then for the client's Citect SCADA. There is also a previously discussed Modbus module on DP. I do not know if Lite will handle this. The processor is a 318 by the way. Will Lite handle this and is there any limitation on the time frame when running etc?

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It looks like you will need STEP7 BASIS. LITE cannot be used for configuring network connections "upwards" (to Citect) or "downwards" (to Profibus DP slaves).
With a big CPU, ethernet and DP in the equation, it does not sound like such a small project, so I would not find the price of STEP7 so excessive if I were you.
Be sure that you get the latest version (v5.4), you can then expect to download updates for free until the next major revision arrives, and that may be years from now.

A small comment:
The 318 has been replaced by newer types. For a new project I would go for a 317 or a 319. They have both DP and Ethernet onboard (317-2PN/DP and 319-3PN/DP), so they will give you much more bang for your buck. And you wont find problems with getting spares after a few years.

Thank you Jesper.

I am not sure about the processor - supplied by the client. I supplied the rest but had only allowed for a 312 and the client wishes to do more with the processor. It may be a 317-2PN/DP - the 319 was not out in Ozz when they bought the processor. it definately has Ethernet and DP on board.

Further, the project is not so large - it is just that the client wishes to use the processor further.

The Step 7 version I have as a demo is 5.3 - hopefully they will supply 5.4 but they told me it was only available in Professional.

When one considers that the whole project is worth $65000 AU to me and I have a generator controller worth $14000 AU and had to build a control panel, battery charger and batteries are worth $2000 AU, PLC parts were $7000 AU, supply design and drawings, co-ordinate other contractors and commission the thing (including paying for a commissioning engineer for the generator controller), re-design the whole main switch board because the consultant was too slack to do so and it would not have worked, there is not a lot of money left for the software. I am counting on further work, which looks almost certain, to "make a bob" out of the whole deal.