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Giving pulse, when changing value on screen

Created by: Andrus_Saar at: 1/18/2023 10:39 PM (8 Replies)

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1/18/2023 10:39 PM	Rate (0)
Andrus_Saar Joined: 10/15/2022 Last visit: 3/31/2023 Posts: 19 Rating: (1)	Hello all Such a question, how to make it so that if I enter a number on the screen and it differs from the one previously given, then a pulse would be given to correct it. I would like such a solution to use a PWM block, so that if I change the length of the period, the work of the block is interrupted and started again, so that the PWM period new lenght takes effect immediately. Otherwise, you have to wait until the former (old) cycle ends. Can this be done without using VM -s? Andrus
	Last edited by: Andrus_Saar at: 01/18/2023 22:40:56 Last edited by: Andrus_Saar at: 01/18/2023 22:41:23
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1/19/2023 3:05 AM	Rate (0)
ixo65 Grandmaster-Expert Joined: 12/18/2014 Last visit: 3/31/2023 Posts: 29553 Rating: (3655)	What do you mean by "Screen"? The LOGO! display? A TDE? An HMI?

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1/19/2023 5:42 AM	Rate (0)
qwazee Platinum Member Joined: 3/30/2020 Last visit: 3/31/2023 Posts: 3321 Rating: (739)	Andrus_Saar Hello all Such a question, how to make it so that if I enter a number on the screen and it differs from the one previously given, then a pulse would be given to correct it. I would like such a solution to use a PWM block, so that if I change the length of the period, the work of the block is interrupted and started again, so that the PWM period new lenght takes effect immediately. Otherwise, you have to wait until the former (old) cycle ends. Can this be done without using VM -s? Andrus Attached is one idea, but it uses VMs. What specific reason do you wish to avoid VMs? Attachment detect-change.png (42 Downloads)
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1/19/2023 11:07 AM	Rate (0)
qwazee Platinum Member Joined: 3/30/2020 Last visit: 3/31/2023 Posts: 3321 Rating: (739)	Next attempt.. Attachment detect-change-no-VM.png (35 Downloads)
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1/20/2023 6:04 PM	Rate (1)
Ella_68 Gold Member Joined: 6/11/2019 Last visit: 3/30/2023 Posts: 1652 Rating: (62)	Hello Andrus_Saar, or do you mean something like that? (Without VM) greeting Ella_68

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This contribution was helpful to 1 thankful Users qwazee

1/20/2023 7:47 PM	Rate (1)
ixo65 Grandmaster-Expert Joined: 12/18/2014 Last visit: 3/31/2023 Posts: 29553 Rating: (3655)	Or mean you something like this?
	Last edited by: ixo65 at: 01/20/2023 19:47:42
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1/20/2023 9:58 PM	Rate (0)
Andrus_Saar Joined: 10/15/2022 Last visit: 3/31/2023 Posts: 19 Rating: (1)	Hi, PWM specialists :) Thank you for any possible solutions, qwazee, Ella_68 and ixo65. I will try to work through them in the next few days and see if it suits me. I want to use PWM to switch the heating cable, whose switching duration would be controlled by a temperature sensor (e.g. Pt 100). The higher the temperature, the shorter the switching time, and at some point it also switches off or in lower temperatures stays constantly on. Presumably I still need to use some VM, because on the pwm block I cannot change the pwm operating range (min and max value) directly from the LOGO! display. And in the event of a temperature sensor failure (short, interruption), for example, the PWM would be with 33% duration and fault message appear in the screen. I want to bring all the parameters to LOGO! display where I could change the length of the PWM cycle, the min and max temperature between which the pwm would work. I'm trying to handle this myself, be patient :) Andrus
	Last edited by: Andrus_Saar at: 01/20/2023 22:02:37
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1/20/2023 10:22 PM	Rate (0)
Ella_68 Gold Member Joined: 6/11/2019 Last visit: 3/30/2023 Posts: 1652 Rating: (62)	Andrus_Saar The higher the temperature, the shorter the switching time, and at some point it also switches off or in lower temperatures stays constantly on. This is due to the values 0 and 1000 of the PWM component and is also correct. If you don't want this maximum behavior, you have to limit the value range of the analog input (e.g.: <1 = 1 and >999 = 999) greeting Ella_68

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1/21/2023 4:02 AM	Rate (0)
ixo65 Grandmaster-Expert Joined: 12/18/2014 Last visit: 3/31/2023 Posts: 29553 Rating: (3655)	Andrus_Saar I want to bring all the parameters to LOGO! display where I could changethe length of the PWM cycle, the min and max temperature between which the pwm would work. If I understood you correctly, then your wish in your first post in this topic was that a change in the period duration via the display takes effect immediately and not only after the end of the current period. That's how I solved it in my suggestion. If yes, then the suggestions of the users qwazee and Ella_68 don't solve this problem.

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