9/14/2023 11:11 AM | |
Joined: 6/7/2022 Last visit: 4/11/2024 Posts: 10 Rating:
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I am very new to the world of PLCs and find it all very confusing, so forgive me please if I haven't posted this in the correct place, or some of my terminology is incorrect (although please do correct me so that I can learn). I have an S7-1200 with CM1241 Module which I have made a project for to be able to communicate with a USS Slave. I followed Tutorial TIA Portal Tutorial #10: Control USS-capable Drives - YouTube and it all seemed to be fine - EXCEPT the format of the Telegram was not as expected. As a summary, that is using the USS Instructions under Communication>Communication Processes>USS USS_PORT and USS_DRV. |
Last edited by: Jen_Moderator at: 09/15/2023 09:03:35Video embedded. |
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9/14/2023 11:21 AM | |
Joined: 4/28/2015 Last visit: 2/7/2024 Posts: 10533 Rating:
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Hello Nick, no place to apologize here. This Forum is very helpful in my opinion. If I could ask you for some ZIP file with jpg screenshots from your cfg of module and also some blocks exactly configured, maybe from your serial PC SW used as check of outcomming byte sequence from PLC. TIA version, HW better described with module exact type and version can be also fine for sure. I have experience that user's description is sometimes not exactly that we can expecet so therefore is good step with some screenshots in ZIP file. Then more users can help in case. What exactly Slave device you have and with what cfg? Update: I've found this eaxmple page where all is described, as next example to you for study: V20 control with USS/MB RTU and S7-1200 I forget to say one thing, in my opinion your frame looks to me like your wrong parity or other comm cfg settings (speed,...), it simply looks absolutelly different to what is expected. |
Last edited by: Duris_I at: 09/14/2023 11:34:40Last edited by: Duris_I at: 09/14/2023 11:45:51With best regards... |
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9/14/2023 12:39 PM | |
Joined: 6/7/2022 Last visit: 4/11/2024 Posts: 10 Rating:
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Hi Ivan, Thank you very much for your response. I also used that example project to try it out in case my simple project from the tutorial video had something important missing, but with the same results. I am also of the opinion that it could be a mismatch in Port settings between the Master and Slave, but I've tried all combinations on the Slave (HTerm) and none produce a Telegram as expected (with STX 02 etc). I don't have my actual Slave yet (a variable speed blower with Frequency Converter from Becker Blowers), but have got a lot of experience of controlling them with both SAS and USS Protocols generated in either VBScript, or in an Anybus Communicator where a Modbus RTU Telegram gets translated, so I know what I'm doing and expecting to see on that front. Until the Coms Module sends out a Telegram that looks correct, my lack of hardware that will respond in a sensible way should not stall my progress. In my mind, the difficult bit is making the project with the appropriate blocks such that a Telegram gets sent - the format of the Telegram should be the easy bit that Functions automatically generate. I've attached a zipfile of various screenshots, please let me know if anything else might be helpful. They include a shot of the receiving Slave HTerm getting a sensible Telegram from a different Master (the Becker config software) to show that it can work correctly, shots of the received Telegrams in HTerm with the 3 different Parities, and then shots of the 3 different Program blocks. AttachmentUSS_Telegram.zip (212 Downloads) |
9/14/2023 2:04 PM | |
Joined: 6/7/2022 Last visit: 4/11/2024 Posts: 10 Rating:
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Hi Ivan. I think I've fixed the issue that you suggested by moving memory allocations so that there are no clashes (maybe the locations don't follow any logic, but does that matter at this stage?) but it has not fixed the problem. I've attached screenshots showing the memory locations, and the incorrect Telegram format still. Please advise further if you can. Thanks, Nick AttachmentMemory Clash Fix.zip (225 Downloads) |
9/14/2023 2:26 PM | |
Joined: 6/7/2022 Last visit: 4/11/2024 Posts: 10 Rating:
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I have done Recompile All and Download All since reallocating Memory and have all green as per the attached. I hope these screenshots give you what you are asking for, I think I understand that much.
AttachmentBlocks.zip (231 Downloads) |
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