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 ?
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.
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.
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
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.
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!!! :)
refused by PLC, i follo as you tell us, " Optimized block access property should be off and PUT/GET must be enabled. Also CPU access protection should be set to full."
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!!
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
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
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
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!
i'm getting this error while trying to read a db from a 1500: "line 403, in read_area check_error(result, context="client")" and "RuntimeError: b'CLI : function refused by CPU (Unknown error)'". Can this issue be fixed? Thanks
Hi Wolfeer, please have a look at my first video for snap7, ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-xSTfmCdepyw.html from 0:25. Optimized block access property should be off and PUT/GET must be enabled. Also CPU access protection should be set to full.
Hi! thanks for your feedback! There could be several reasons, did you check if "optimized block access" property is turned off? Is the PUT/GET enabled? Access level should be set to full. You can have a look in the following links for some more description. stackoverflow.com/questions/47979438/s7-1200-snap7-exception-cli-function-refused-by-cpu-unknown-error sourceforge.net/p/snap7/discussion/general/thread/c9ec5278/ I hope you will find your issue. Please let me know how it goes! ;)
Hello. Very good video but I couldn't connect with plcsim (cpu 1200). If possible, post a video about transferring webcam video (if there is such a thing) to hmi in TIA or wincc and connecting it to s7-1200. Thank you
Hi, Could you please let me know if it is possible to use Snap7 for updating PLC program (I have existing program running on PLC. I have made some changes to it on another machine and i created archive of the project in another machine. Now i want to upload the archive project to PLC, is this possible using Snap7 library)
Hi, Could you please let me know if it is possible to use Snap7 for updating PLC program (I have existing program running on PLC. I have made some changes to it on another machine and i created archive of the project in another machine. Now i want to upload the archive project to PLC, is this possible using Snap7 library)
Thank you for this tutorial. Can you describe the difference between snap7 and OPC UA when connecting to Siemens PLC? Is snap7 for Siemens something like ADS protocol for Beckhoff PLCs?
Hi! Thanks for your feedback. OPC UA is industrial standard for data exchange. (en.wikipedia.org/wiki/OPC_Unified_Architecture) Snap7 is something to interface directly with the S7 communication protocol which Siemens uses in theirs PLCs. (snap7.sourceforge.net/) I am not familiar with Beckhoff and ADS so I am not able to compare it and tell you if it is something similar.
Hi Ali, You can take a look at this link: github.com/gijzelaerr/python-snap7/blob/master/example/write_multi.py It is an example of reading and writing different types than boolean. I hope it will be helpful. Let me know how did it go!
