Hi there!

I just started playing with these devices some days ago, my first steps on PLC programming

I bought a S7 1200 v3 (HE31).

I took my first steps and programmed it with TIA portal and some basic ladder test program with flipflops, timers, etc. All working good so far

Now I wanted to practise with HMI programming. I don't want to spend the cost of a real HMI for now so I tried to simulate one on TIA Portal. My goal was getting a simulated HMI screen on my laptop and have it interact with my physical S7 1200 (not emulated)

Can this be done?

I created a basic 7" HMI (KTP700 Basic with Profinet), and stated (in the program, as I don't physically have one), that it was linked to my PLC_1

Then in the HMI properties, for all the buttons events, I browsed to find the PLC variables it would read from/write to, and it actually showed me the PLC's default tag table and showed the real variables I was using there.

Then, after I uploaded the code to my PLC, I invoked the simulation of the HMI, and in the compile time it complained with "Invalid internal data type" in all the events in the HMI. The error pointed me to all the variables I had linked to my PLC with no more detail on why it didn't like th actual PLC variables it allowed me to link seconds before.

So I was wondering if I can SIMULATE an hmi connected to a REAL s7 1200 PLC?

Thanks a lot!

Eduardo

Hello Edugimeno,,

Yes, that is possible.

First you will have to clear the errors when you compile.

Perhaps you can get some screenshots with information.

Best regards,

Wizard

Oh...of course it would happen...I didn't save that project, so I just recreated it all from scratch to get all screenshots and you know what...Now it works.

I assigned a couple button events to inputs (I0.0 and I0.1) and although in this case it didn't complain during compilation, the HMI buttons didn't have any effect.

So I added a memory tag (not input) switch in paralel to the input switches and those worked.

Can't I send SetBit or ResetBit to physical inputs (I0.X...)?

Thanks

Edugimeno

Can't I send SetBit or ResetBit to physical inputs (I0.X...)?

Hello,

No that is not possible.

Because every cycle the input wil be overwritten. (By hardware input)

You should use Memory bit instead.

Best regards,

Wizard 

Gotcha, so if my process has to be controlled by both real inputs and a HMI screen, I should keep both parallel switches, one to Ix.x and another to Mx.x, and if it only has to be controlled by HMI, the switch from M should suffice, is this right?

Edugimeno

Gotcha, so if my process has to be controlled by both real inputs and a HMI screen, I should keep both parallel switches, one to Ix.x and another to Mx.x, and if it only has to be controlled by HMI, the switch from M should suffice, is this right?

Yes you have it right.

One small detail as addition - Tags from M-memory is not the only way of linking HMI and PLC. You can also use tags generated from data blocks.

Some designers like this option more as it presents the opportunity to group same functions together.

Sorry but I'm a complete *** and just landed into this world 3 days ago and I would use some additional help if you don't mind, asnow as I read your explanation I see there's something I'm not getting well.

I opened the PLC-Tags>Default tag table. There I inserted a new tag, named it tag_1 (automatically...), type bool, and address M100.0. I understand this is a memory value. How does this differ from what you are propossing?

Thank you in advance!

EDIT; Ok I found how to do data blocks. I added a DataBlock, inserted 2 tags, and changed all references (in OB and in HMI) to use these tags instead of the M tags. It works fine.

But I would like to understand what (internally) differs from one method to the other. Is one of them persistent after power off and the other is no? Or what else changes from one way to the other?

Thanks!!

My problem, if it can be called "problem", is that I feel prettu comfortable with lots of technologies "around" PLC's, but haven't touched a PLC at all till last week.

I have many years of experience in programming. ASM (Z80, 8086, 68000), C for Unix, C for MSDOS, C++ for Linux, Pascal, PHP, unix scripting, some pythoon/perl/etc.

I am also good in electronics, both digital and analog. I've been using almost daily several Arduino platforms for work and home projects.

So I come to a world where most of the people need introductory training into programming, electronics, etc. All the courses I've seen spend lots of time into all those preliminary lessons which I feel comfortable with-

So trying to dodge all the unneeded extra training Im trying to go stright to the required knowledge I'm missing. Straight PLC. Then I went ahead and bought a used S7 1200. I managed to coonect to it, program some basic LAD program, upload and test it and I feel good with that. I understand that from there on, things can get more complicated when the program requirements get more complicated, but in general I feel good being able to assign an IP to the PLC, connect to it, download a program, modify it, upload it, etc

From there on, I feel I may eventually require some training into HMI's and maybe in communication between PLC's and between PLC's and PC's. Right now I do have spare time and I feel able to self train in all these, before I go to an specific training class, which I may eventually join in the future

As you see in my case I don't have any specific project. I just want to spend some time training myself and feel confident with a technology that I've always felt I've left aside, while I've always been so close to it.

#dP

Hello.

There are different levels of new:
1) New to programming
2) New to PLCs (can program in C / Python / ..)
3) New to Siemens PLCs (know other brands)

Which level are you at?

A good place to start is:
The TIA Portal Tutorial Center (videos)
(click on the play button to enter the library)

Now here is the risk - it is possible to dive so deep into the details that your project does not get done. Consider how much time you can afford to study the "text book correct way". Starting projects does not need to be 100% correct format.

As to why DBs - organise your data in grouping you control and more efficient (quicker) processing.

What is your opinion?

You have a very good base to start from. Your experience with Pascal will help you in learning the SCL language, though I have in mind you might like FBD more.

The videos will help you form a more in-depth idea on what things are about. Be a little patient with yourself and go through the videos that shows the concepts.

The S7-1200 System Manual is a very good resource. The introductory chapters are boring, but you are now at that stage of your development that you need to understand those concepts.

The best learning you can do is if you have a project. It can be something in your home that you hope to automate. It can even be designing an alarm clock. Focusing your inquiries makes the lessons you learn more valuable.

Siemens has published some libraries that is worth looking at.

Note that I am not giving links this time. It is with purpose. When spending time searching for one thing you find by accident other things. Not immediately helpful but of worth later on.

Happy hunting.