2/7/2018 4:42 PM | |
Joined: 3/25/2014 Last visit: 9/5/2022 Posts: 13 Rating: (0) |
Hello. -Operating System: Win7x64 (VMware) - TIA Version : V14 - Service pack and update : SP1 - Hardware Modules numbers :---- - The desired application : "PLCSim" or "PLCSim Advanced" - The Problems (Bugs) : I can read values while OB1 is running. simle code of OB1: "Data_block_1".ML := TRUE; . . ...some lines of code...for example: 100. No one line use "Data_block_1" . . "Data_block_1".ML := FALSE; That's all. I try to readout value of "Data_block_1".ML - and I see (sometimes) value "TRUE" instead "FALSE" as expected. I have a video, but you can't see "PLCSim Advanced"-window (I don't know why). Best regards. |
2/7/2018 5:02 PM | |
Joined: 7/7/2010 Last visit: 10/14/2024 Posts: 15306 Rating: (2428)
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I am not sure what you are complaining about. By that I mean, I cannot tell what the bug or problem really is. Are you saying the communications is able to grab inconsistent data from the plc rather than only at the end of all program scan OBs? Is your DB configured as absolute or symbolic for addressing? I am assuming absolute. If so, is it possible something is affecting the value without you wanting it to? It is rather easy to do with absolute addressing. Does your main OB call any FBs or FCs that access any data in that same DB? Do you have an HMI accessing that DB remotely and possibly modifying the value? Is it possible the problem only exists in the simulator? Does the behavior persist on real hardware?
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science guy |
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2/8/2018 6:37 AM | |
Joined: 3/25/2014 Last visit: 9/5/2022 Posts: 13 Rating: (0) |
Yes, I tried this code with real CPU (1511-1pn), on "PLCSim" or "PLCSim advanced" - the picture is like in my video. On the real CPU this bug is even more often (you can watch on the video).
Of cause absolute, only those 2 commands use DB.
There is no any other FBs or FCs and HMI. My program use S7IsoTCP-connection and controller use "Permit access with PUT/GET...". This bug happens with variables in merker and "Q" too. Trying with TIA-portal simulated HMI (only read this bool) - also bug present. In this test I deselect protection "Support simulation during block compilation" (need in PLCSim's). Best regards |
Last edited by: denzhig at: 2/8/2018 6:44:17 AMLast edited by: denzhig at: 2/8/2018 6:47:46 AMLast edited by: denzhig at: 2/8/2018 7:02:56 AMLast edited by: denzhig at: 2/8/2018 7:03:44 AMLast edited by: denzhig at: 2/8/2018 7:06:58 AM |
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2/8/2018 8:10 AM | |
Joined: 3/25/2014 Last visit: 9/5/2022 Posts: 13 Rating: (0) |
The same picture if I using OPCUA connection - BUG is present. |
2/8/2018 10:01 AM | |
Joined: 9/23/2005 Last visit: 10/15/2024 Posts: 4756 Rating: (726) |
I'd say it's great, thanks to that so-called online monitoring is possible. Then I can tell you you were wrong. It must nothing.
To call some behaviour a bug it must be proved that it is against definition/declaration/standard etc. And Siemens declares here: "All cycle OBs always have the lowest priority of 1. The highest priority is 26. Communication tasks always have priority 15." If you need to have some variables captured at certain point of a OB scan it's your obligation to capture them and store somewhere where they will stay intact. |
Regards, |
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2/8/2018 10:51 AM | |
Joined: 3/25/2014 Last visit: 9/5/2022 Posts: 13 Rating: (0) |
I'm starting to think that this is "feature", not a bug. BUT in S7-300/400 - all works fine. For example: you have a very long formula, how to calculate it? right: res := a+b+c; res := res+d+e+f; & etc So now this is not possible and you need more variables (more memory...) . . . Ok, this is not a "bug", this is "feature". For me - I need to use OB30 & ect instead of OB1 (and calculate cycle time manually). |
Last edited by: denzhig at: 2/8/2018 11:33:42 AMLast edited by: denzhig at: 2/8/2018 11:34:29 AM |
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2/8/2018 11:56 AM | |
Joined: 3/25/2014 Last visit: 9/5/2022 Posts: 13 Rating: (0) |
use OB30... instead of OB1 and manual calculate cycle time |
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