i try to reduce the sampling interval of data of pressure at WINCC (inferior to 1 min to 0.5 sec) to exported to matlab , can someone help me?
To be able to provide you with some answer, you have to be more specific. So, please, try to answer these questions and than I will try to help you. :)
Which version of WinCC do you use? Is it WinCC Flexible, WinCC 7.3 or is it WinCC in TIA portal - WinCC Advanced or Professional?
Are you running your application on PC or you have HMI panel?
Do you need to reduce the sampling time between WinCC application and PLC? Or you need to change the rate of writing the data into some export file?
What is your hardware configuration?
thank you for your interest,
i work with WinCC 7.0 Professional, that is running on PC to supervise pump station, i need to export flow data in excel to work with it at matlab , i want to identify my model offline
i get transfer function:
Gm =
100
exp(-7.8*s) * ----------- but normally is
393,6s + 1
Gm = 1
exp(-7.8*s) * -----------
3,936s + 1
when i tried to reduce the simpling at configuration tool
Hi,
if you are using the data logging functions of the WinCC - "Historical data", then you are able to log with 1s sample rate, it is not possible to get lower sampling period in this way.
But you can write your own script to export the data into a file and call it with lower cycle time (100ms is the fastest). Try to have a look at the examlpe here:
https://support.industry.siemens.com/cs/document/850338/how-do-you-export-and-reimport-wincc-runtime-data-?dti=0&lc=en-WW
Of course take care of the HMI tag "Acquisition time" this could be also 100ms maximum speed.
So be careful to not have the export time faster than the HMI tag Acquisition time.
The other possible way how to get the data with higher sampling rate is to implement the logging in the PLC and export it at once after the measurement. My choice would be to do it in PLC.
thank you for your answer , i reduce the cycle time , i'm testing Closed-Loop Setpoint Response to identify model
Your welcome,
there is a lot of methods for system model identification and I don't know your application, so it is hard to provide you with any advice. However, if you will have any other questions, don't hesitate to ask.
Good luck with your research.
oh thank you so much ,
i identify my modal off line with matlab and apply SIMC rule to tune pi controller , i'm phd student , i know that there is lot of methode but i want to use optimization methods with data , give a simple and an updating technique to tune PID controller , if you have any suggestion ? my mail is [email protected]
#1.Do you have also a real system or you work only with matlab model? - what is the source of the data, are you able to verify the optimization results etc. Will be your work more theoretical or you have also practical application of your result. What is your system normal working conditions - is it working around one value set point or you need to change the set point more often in wide range of values?
#2.What is the aim of your work - you want to optimize some specific system, or you are working on some methodics?
All of this questions should help you to specify your area of interest, so you can focus on some specific problem and solve it. You should make some analysis of methods, to find out which fits you the best.
yeah, i work at pump station, and the data is real, i excit the process with step test on closed loop , ( control flow ) with only P gain, to identify my modal after in matlab i want to apply some tuning rule for comparaison
in attached is an exemple in wich area i work
thank you
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