9/29/2022 7:34 PM | |
Joined: 9/21/2012 Last visit: 10/18/2024 Posts: 4181 Rating: (468) |
I'm with qwazee, we need to see how you are using the timer. |
9/30/2022 8:41 AM | |
Joined: 11/16/2018 Last visit: 10/3/2024 Posts: 22 Rating: (0) |
I attach here two examples, one TON and one TOF. TON: here you see already my solution to the problem with the memory clock bits (Trigger 1000ms). Before, you can see, the timer was simply put between its output at Q and the output negated at IN, but it was not working, so I made this workaround. TOF: i'm still using this, but it blocked a plant last week for days, so I will have to replace the timer with something else. You can also see, that if I reset the HEAT_STA_REQ while the timer is running, I wil not get the falling edge at IN (it's ok). Nevertheless, I don't see how the absence of an input at IN would cause the ET to go past the PT, with a TOF. It really happened, so I set the "Manual_Trigger" to reset the timer, and then the ET went past the PT again (I tried several times). Then I modified the FC, without any change, downloaded, the DB was not reinitialized, but the timer started working fine again. How do you think this is possible? Attachmenttimer_not_resetting.zip (466 Downloads) |
Last edited by: vcamp7 at: 09/30/2022 08:41:43 |
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10/3/2022 10:32 AM | |
Joined: 11/16/2018 Last visit: 10/3/2024 Posts: 22 Rating: (0) |
@jacek d: Instead of looking at experience, please look at the code. I have not found any topic about this problem with timers in the forum so far.
Thank you for your reply. |
10/3/2022 5:20 PM | |
Joined: 9/21/2012 Last visit: 10/18/2024 Posts: 4181 Rating: (468) |
In Network1, you are quering the .Q before the timer execution. In Network2, you query the .Q after the timer execution. |
10/3/2022 6:31 PM | |
Joined: 7/7/2010 Last visit: 10/18/2024 Posts: 15327 Rating: (2432)
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So you are saying S7-1x00 PLCs scan top to bottom, then left to right? Seems contrary to how things are supposed to work in ladder logic.
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science guy |
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