Python OPC UA client communication with Siemens PLC TIA Portal

[@plcwars]

Hi plcwars Community! I’d love your help in planning future content! Please take a moment to fill out this quick form. Fill out the form here: forms.gle/BBsFx7XRf7wUVEda8 As a thank you, you’ll get a link at the end of the form to download my OPC UA Cheat Sheet - a useful guide for working with OPC UA in Python. Just complete the form, and the download link will be yours! I’m really proud of this OPC UA cheat sheet and excited to share it with you - creating these resources is something I genuinely enjoy! If you notice any mistakes or have suggestions, please let me know - your feedback helps me improve! Thanks for being part of the community!

[@tejaswinirajput1576]

Thank you so mush for this video. Grateful to find this video.

[@zachivan2928]

thanks bro for those useful opcua python function,it really helps,ON Chinese version of Youthbe Bilibili I can‘t not find enough information about how to use opcua and anyncua to opera the PLC,many thanks!!! :)

[@jelker5778]

Very usefull, thank you!

[@jeroenconinx6121]

Thanks so much!

[@LinoJr.Asmolo]

Hi @plcwars, how about connecting OPC UA client to server with certificate and private key? Do you have tutorial? Because I couldn't find any videos that uses certification and private key.

[@plcwars]

Hi! I have personally not done it, but maybe this link helps: opcfoundation.org/forum/opc-ua-implementation-stacks-tools-and-samples/opc-ua-client-sample-with-signandencrypt-basic256sha256-certificate/ You can also join our discord and ask there, maybe someone knows.

[@LinoJr.Asmolo]

@@plcwars, thanks for your reply. I will look at it.

[@LinoJr.Asmolo]

Hi @plcwars, how about via api to connect to an OPC UA server? Have your tried it? Thanks.

[@plcwars]

@@LinoJr.Asmolo unfortunately I have not used it

[@LinoJr.Asmolo]

@@plcwars , okay. Thanks.

[@martinferrand4711]

Lovely!

[@maxpenfold8699]

nice! 😊

[@jesusmartinalcala4730]

Hello, thank you really much for the amazing videos! I have a doubt, in case that i want to read real time data from the machine such as setpoints or sensor readings, do i have to create a DB like you did or could read straight the values? Thank you in advance!!

[@leezhaohong5239]

well done!

[@rom3453]

great!! :)

[@BartHoevenaars1]

one question, how to write a FLOAT to the server ??

[@plcwars]

new_value = 53.0 variant_value = ua.Variant(new_value, ua.VariantType.Float) node.set_value(variant_value)

[@asuna-k9l]

hi, great video, I am new to this and don't understand how to create an instance, at 1:30 into the video you reverence the instance opcua_python and I don't know where this comes from or how to make one, any help would be very helpful, thank you

[@plcwars]

Hi, thank you! This is just an instance of the plc. It means basically that you have to create a simulation of the PLC. This is a simulated PLC device. If you just type a name there and select start it should work. If you need more help you can join the discord server and you should get more detailed support there.

[@asuna-k9l]

thank you@@plcwars

[@sargaps2825]

Great video .. Thank you so much..I have a doubt, I was not able to start the opcua_python instance in PLC sim advance.. The start button is disabled while using virtual ethernet adaptor..What should I do ?

[@plcwars]

You can join our discord community, it would be easier to help you there. Without any screens it is quite difficult to know what is wrong.

[@rezamagham4495]

Thanks please tell us how to communicate by scada pack with python

[@plcwars]

Hi reza, I never had opportunity to work with scada pack so I am not sure if it is possible.

[@metehancihan6943]

Hello, thank you for the video first. I made some steps with this tutorial. But now i have the problem that when i change the values (DB100, just some variables. isnt connected with the rest of my sps program yet) in my opcua server (Booleans) they all are set to TRUE and i dont know why. Is this a known Problem? When i print out the client_node_dv (the DataValue for the OPCUA-Server) on my console with print() the values are as i want them to be. It seems like a Problem in the Connection between Server and TIA. Would be nice if u could help me out. Thanks

[@plcwars]

Hi Metehan, you could have a wrong data type defined so you would overwrite more values than you intend to, as an example you would like to change one boolean but you try to write int then you will overwrite more than one bool. I am not sure what exactly is the problem, so the values that you read from opc ua are different than the ones online in the plc? I came up with an idea of creating a discord channel so it would be easier to help in such cases: discord.gg/kU3g94rNXx

[@3coco322]

Hello, i tried to run the "opcua-client"-command, but it didnt recognize the command...do you know what the problem could be? I installed the required packages and also installed winpython with PyQT5 but its still not working Thanks in advance!

[@plcwars]

Hi! What message do you get back exactly in the terminal? Did you try to copy it and search in the google? This could be helpful.

[@vigneshk.r9959]

run "app" inside folder "opcua-client-gui-master"

[@MunishReddy]

Amazing video. I am trying to read the values after every 5 secs. Any help would be appreciated.

[@martinferrand4711]

I'm not very well versed in Python however there are multiple path you could take: - A loop (basic but lack flexibility) - same loop but in a thread so it doesn't prevent the rest of the from working (however you have to be careful) - Event based system (no clue how one would do that in python) (maybe the Queue package could help) - Scheduler (never tried) It depend on what you want to do. Maybe there is a way to something better using python or the automaton Edit: Added some options

[@plcwars]

as mentioned above I would try with task scheduler to run a script, on linux based systems equivalent would be cron task