5/4/2017 6:07 AM | |
Joined: 12/18/2014 Last visit: 4/26/2024 Posts: 32891 Rating: (4066)
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Since you do not describe exactly what input it is, so I can only make assumptions. Also, you have not written how high the speed is (rpm). For normal digital inputs, Siemens only guarantees a frequency of 4Hz, which corresponds to 240 rpm. For higher frequencies, you Need a LOGO! which can only be supplied with pure DC voltage. These LOGO!s have fast inputs, in which Siemens guarantees a frequency of 5kHz, which corresponds to a speed of 30,000 rpm. From these fast inputs the corresponding LOGO! has each 4 (I3-I6). Digital expansion modules do not have these fast inputs. In addition I would program the speed evaluation differently, see attachment. AttachmentSpeed_0BA8.Standard.zip (1775 Downloads) |
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5/5/2017 7:34 AM | |
Joined: 12/18/2014 Last visit: 4/26/2024 Posts: 32891 Rating: (4066)
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The precision of the display depends on the number of measured pulses, the measurement period and the factor.
For a measuring period of one second, the speed is updated every second, with a measuring period of 10 seconds, the update takes place every 10 seconds. In attachment there is a new example. In this you can for testing in the simulation changing the measuring period over TDE Display. AttachmentSpeed_V2_0BA8.Standard.zip (1310 Downloads) |
5/6/2017 6:55 PM | |
Joined: 12/18/2014 Last visit: 4/26/2024 Posts: 32891 Rating: (4066)
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Here is an example of how to calculate the speed by measuring the period between 2 signals of the speed sensor.
AttachmentSpeed.zip (1242 Downloads) |
This contribution was helpful to2 thankful Users |
5/14/2019 6:49 PM | |
Joined: 10/27/2017 Last visit: 1/24/2024 Posts: 3 Rating: (0) |
I think I was doing a simple version somewhere, I will look for it and upload it |
5/14/2019 7:51 PM | |
Joined: 10/27/2017 Last visit: 1/24/2024 Posts: 3 Rating: (0) |
I found it
Attachmentот импулси към аналогов изход за мотор.zip (633 Downloads) |
6/13/2020 2:03 PM | |
Joined: 2/8/2020 Last visit: 2/10/2022 Posts: 9 Rating: (0) |
Greetings ixo65. I was tinkering with your example and I wanted to add another rpm sesor to the same programm and so I duplicated everything but the second one does not work. B014 returns 32,767 while B004 works fine! I dont see what is going wrong! Here is what I did: AttachmentSpeed 2x Sensors.zip (519 Downloads) |
6/13/2020 2:35 PM | |
Joined: 12/18/2014 Last visit: 4/26/2024 Posts: 32891 Rating: (4066)
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Hello CountPap, I don't know what is wrong with the mathematic block. I delete complete the logic for the second sensor and make it new. Now it works. AttachmentSpeed 2x Sensors_V2.zip (565 Downloads) |
Last edited by: ixo65 at: 06/13/2020 14:44:13 |
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This contribution was helpful to1 thankful Users |
4/26/2021 11:02 PM | |
Joined: 2/22/2008 Last visit: 2/22/2024 Posts: 2698 Rating: (206) |
It is also possible to display RPM up to 300,000 with a little trick, but you need at least a Logo8 FS4 or a new Logo8.3, see attachment for example. In simulation just change I3 to frequency mode and type in 5000. The first multiplication by 6 is done with the arithmetic, 5000 x 6 = 30,000 is okay for this block. Multiplications by 10, 100 or 1000 you can make with the I/F and F/I converter. The eAQ output can be used in messages for higher values than 32767, but you cannot calculate with such values. Regards, Scorp AttachmentRPM300000.zip (609 Downloads) |
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