Hi Stefano, First of all: welcome from me too :-)
Let me also please take the opportunity to add even more on this. As Julian already mentioned, Siemens did a little trick to not really make the protocol much securer than without, however it renders us unable to publish an open-source driver without getting into some legal minefield. However I was already thinking of starting to work on this driver anyway. However this driver would then only be a so-called passive mode driver. With this we would not be doing the stuff that would be problematic. However you couldn’t explicitly ask for data, but could only read any data someone else asked for. So if you want to actively read, you currently have to stick to Julian’s suggestion. Right now the only option I can see this to change, would be if Siemens decided to accept and adopt PLC4X and either provide us with the specs for the driver (probably not going to happen) or they decide to provide closed-source versions of PLC4X drivers themselves (Not totally out of question). But generally using an IO memory block is actually not a bad thing, as it might even improve the overall performance. As the IO part wouldn’t have to extract bits of information from all over the place, we could even load big chunks of data. Right now we don’t yet have the proposed “query-optimizer”, but it’s on our roadmap. With this, we’ll be able to dramatically increase the throughput of IO while reducing the load on the PLC itself. Right now I would probably even opt for using an IO memory block, even if we had a working S7plus driver (Seems that’s how Siemens internally calls the protocol needed to access these optimized blocks) for these performance reasons. Chris Von: Stefano Bossi <[email protected]> Antworten an: <[email protected]> Datum: Sonntag, 5. Juli 2020 um 11:48 An: <[email protected]> Cc: Daniele Rimoldi <[email protected]> Betreff: Re: AW: Reading compress Data Block Dear Julian, thanks for your kind reply, I will study the video you post me and I will try to understand with the PLC expert if using "plain" block will be an issue or not. Thanks, Stefano Bossi On 04/07/2020 23:13, Julian Feinauer wrote: Dear Stefano, first, welcome to this list and thank you for your kind words! I, and many others here on the list would love to be able to read "optimized Data Blocks" from Siemens. There are technical as well as legal reasons why we do not provide such a driver as of now. I (and others as well) hope that we will be able to do it one day but so far we cant. In our industrial applications we usually copy the block over to another unoptimized Block which we use as "exchange block". Tim talks a little bit about that in the video we did together on PLC4X: https://www.youtube.com/watch?v=MIp_0OcDTr4 [https://i.ytimg.com/vi/MIp_0OcDTr4/maxresdefault.jpg]<https://www.youtube.com/watch?v=MIp_0OcDTr4><https://www.youtube.com/watch?v=MIp_0OcDTr4> "Hands On": Reading Siemens S7 with PLC4X<https://www.youtube.com/watch?v=MIp_0OcDTr4><https://www.youtube.com/watch?v=MIp_0OcDTr4> In our first (technical) webinar Julian Feinauer and Tim Mitsch as members of the Project Management Committee (PMC) of PLC4X will introduce the Apache PLC4X... www.youtube.com<http://www.youtube.com> If you have more questions we will try to help you with that or give you enough advice what to tell the PLC programmer guy : ) Best! Julian ________________________________ Von: Stefano Bossi Gesendet: Samstag, 04. Juli 2020 15:31 Bis: [email protected]<mailto:[email protected]> Betreff: Reading compress Data Block Dear plc4x developer, my name is Stefano and I am dealing with a project which is briefly reading data from a Siemens 1200 or 1500 and use these data to make some statistics. I am writing a software in Java with your wonderful library but I didn't written the PLC software (some automation expert guy wrote that) The PLC software has some DB I need to read but the PLC use "optimized Data Block". Is there a way to read with PLC4X library an optimized Data Block ? Many thanks for your work! Regards, Stefano Bossi
