Relay Auto Tuning in Step 7

Dear Team,

As a student in my university i have to create a project in Step 7 for relay auto tuning of PID Controllers using the SIEMENS SIMATIC S7-300 based on an article. After successfully recreating the algorithm in matlab i fail to imagine implementing it in Step 7 or TIA Portal. I am absolutely new in the filed of PLC Programming as the only projects i have worked on have nothing to do with my current asssignment.

After browsing the internet looking for suitable articles and tutorials I failed to find one describing the procedure of creating a complete auto-tune project from ground-zero and sincerely hope you can bring a light into my tunel.

Thank you in advance!

Hi and welcome to the forum!

It would certainly be easier for you to convert from Mathlab to Step7 if you could use CFC.

If you could use B+R or CoDeSys/Twincat V3 instead of Simatic, Mathlab could be run directly (as I have understood it, never tried though).

Btw, there are autotuning functionality (from Siemens) for both S71200 and 300/400 existing already.
Here's a link to Siemens' support sites, tema is autotuning:
http://support.automation.siemens.c...search&searchinprim=&nodeid4=20208582&x=0&y=0

Kalle

Dear Kalle,


Thank you a lot for the quick response!

I reviewed several articles and threats about the auto-tuning procedure but there was no detailed description of the used procedure and algorithm. Most of the suggested articles were for TIA Portal and not for Step 7. As well there are no examples/ tutorials on that matter even in the Siemens forums or knowledge transfers.


I am starting to believe that this matter is quite restricted and probably not a good option for a Step 7 begginer like me

There are loads of information on the Siemens support site
Do a search for fuzzy, modular pid and standard pid control
Download the manuals and start reading

Relay Auto tuning PID controller in Siemens S7

Hi I am doing the same thing for my college projec. can you please help if you figure out how to do it. I am also looking on internet have some idea regarding the development of PID controller but how to tune it... still do not know this..
please help if you already got this.

regards
Ajay

autotune is done by having the parameters in a low mode.
then change the setpoint with 2 % automatic.
if reaction is good then P factor is added, until the system begins to oscilate.
the P factor is reduced to 90%.
then do same with I factor.
then with D factor.
after a while you will get the best settings for the setpoint.
then change something in your process and do above again.
make a report of it and you will have A.