9/17/2020 9:58 PM | |
Joined: 3/3/2020 Last visit: 12/9/2023 Posts: 44 Rating: (0) |
I found PWM by trial and error.... I'll try with it. |
9/17/2020 11:01 PM | |
Joined: 2/22/2008 Last visit: 8/6/2024 Posts: 2698 Rating: (208) |
The PWM block will not help for higher frequency, the time base is 10ms. Therefore the minimum periode time is 20ms, this is max. 50Hz. If you need higher frequency, they will change with the cycle time of the Logo controller. This is not usable for an application with high resolution. See program in attachment for different pulse generators and test it directly in a controller, a PC simulation will show wrong frequencies. The fastest generator can also be used with a counter to get an adjustable frequency, but this is the next step, if you give concrete informations for your required signals. Connect your transistor output Qx in the program to any generator to test the output signal with e.g. an oscilloscope. I don't know, which signal is sended at the really output. Regards, Scorp AttachmentPulse generators.zip (172 Downloads) |
This contribution was helpful to1 thankful Users |
9/18/2020 12:47 AM | |
Joined: 9/27/2006 Last visit: 10/28/2024 Posts: 12292 Rating: (2689) |
Hello Dmitry; Maybe this scaling block for Logo! Soft Comfort ca help you in this task: How do you scale measured values in LOGO! Soft Comfort? https://support.industry.siemens.com/cs/ww/en/view/26671120 But if, as you say, 0 mA is 0 Hz and 20 mA is 20 Hz. Then the linear scaling gradient of the function should be very easy to calculate... Hope this helps, Daniel Chartier |
9/18/2020 10:45 AM | |
Joined: 2/22/2008 Last visit: 8/6/2024 Posts: 2698 Rating: (208) |
First the baby is crawling, then walking and later running. We don't know, if the signal output is working, but searching for program solutions. See program in attachment for a possible dependence, but it is not possible to get a linear characteristic, because you must use an inverse function. The Offset is used to have an analog value without a sensor. Normally you get 200 for 0mA and 1000 for 20mA. Just edit this value to adjust the input value without sensor. The formula is 20000 x 5 / input value to get 20 Hz with an input value of 1000. But this you have to adjust depend on the cycle time of your controller. With higher frequencies you get rough steps. Regards, Scorp AttachmentAdjustable pulse generator.zip (179 Downloads) |
This contribution was helpful to1 thankful Users |
9/19/2020 11:04 AM | |
Joined: 3/3/2020 Last visit: 12/9/2023 Posts: 44 Rating: (0) |
Thanks, I'll play |
Follow us on