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CALCULATING RPM

Created by: Deleted User at: 1/1/2012 6:49 PM (5 Replies)

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1/1/2012 6:49 PM	Rate (0)
Deleted User Posts: 767 Rating: (69)	Dear all, In one of the our projects, our client want to synchronize two motors with together. Each motor has one VFD drive and one pulse encoder (1000). At the first, I want to read pulse encoder’s data (Motor No.1) by S7-1200. After that I want to convert (Unscale) RPM’s of first motor to pulse for command to second motor. These are my questions: 1. How can I calculate motor’s speed (RPM-round per minute)? 2. How can I unscale RPM to pulse? Do you have any solution for this project? I’m looking forward for your reply. Best regards, HWF
Deleted User Posts: 767 Rating: (69)
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1/2/2012 10:50 AM	Rate (1)
Denilson Pegaia Platinum Expert Joined: 9/23/2005 Last visit: 11/29/2023 Posts: 4277 Rating: (1377)	Hi, By definition RPM = numberof pulses / 1 minute. If (as normally) you can't "to wait" one minute, you can use a delta time sampling: RPM = number of pulses that comes in a delta time* conversion from delta time to 1 minute For example delta time = 100ms 1 minute = 3.600.000/100 = 36.000 RPM = number of pulses that comes in 100ms* 36.000 To forward the pulses from one drive to the other, I suggest you to use a wired connection (without pass throught the PLC).
	Denilson Pegaia Siemens Industry Sector Technical Support
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1/4/2012 11:48 AM	Rate (0)
Deleted User Posts: 767 Rating: (69)	i need sampel progeram for calculting in s7-1200 . with encoder 1000 pulse best wish for you
Deleted User Posts: 767 Rating: (69)
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1/4/2012 3:52 PM	Rate (0)
Denilson Pegaia Platinum Expert Joined: 9/23/2005 Last visit: 11/29/2023 Posts: 4277 Rating: (1377)	Hi you need to take in count the number of pulses per turn too. rpm = number of pulses / (number of pulses per turn of encoder) / time
	Denilson Pegaia Siemens Industry Sector Technical Support
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10/16/2013 7:03 PM	Rate (0)
Ilshatik87 Experienced Member Joined: 10/18/2012 Last visit: 2/1/2023 Posts: 18 Rating: (1)	If you have any sample project please to share please!

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4/5/2015 11:30 PM	Rate (0)
saeed.maghami Posts: 30 Rating: (1)	https://support.industry.siemens.com/tf/ww/en/posts/fm-350-1-frequency-measurement-contineous-counting/49877/?page=0&pageSize=10
saeed.maghami Posts: 30 Rating: (1)
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