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parameter to convert from Rpm to Hz

Created by: GUWS at: 10/2/2020 3:46 AM (17 Replies)

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10/2/2020 3:46 AM	Rate (0)
GUWS Bronze Member Joined: 4/18/2014 Last visit: 3/26/2021 Posts: 241 Rating: (3)	Hi, i am using G120C VFD and i want to convert the Speed setpoint from RPM to HZ. i try to search in manual but i never found the exact one. please advise me.

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10/2/2020 8:53 AM	Rate (0)
jacek d Platinum Member Joined: 9/23/2005 Last visit: 4/19/2021 Posts: 3330 Rating: (524)	I'd advise you reading a handbook on electric machines first.
	Regards, Jacek What is confusing you is the fact that you never see a number but always its digit representation. So you end up thinking that the number is the representation. - Andrej Bauer Any claims against me - based on whatever legal reason - resulting from the use of any code and/or ideas presented on this forum shall be excluded.
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10/2/2020 9:20 AM	Rate (0)
GUWS Bronze Member Joined: 4/18/2014 Last visit: 3/26/2021 Posts: 241 Rating: (3)	jacek d I'd advise you reading a handbook on electric machines first. Wow thats great advise..... Thanks

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10/2/2020 9:30 AM	Rate (0)
PISCEAN 2010 Platinum Member Joined: 4/23/2010 Last visit: 4/18/2021 Posts: 6552 Rating: (600)	GUWS Hi, i am using G120C VFD and i want to convert the Speed setpoint from RPM to HZ. i try to search in manual but i never found the exact one. please advise me. Set r0002 = r0024
	Last edited by: PISCEAN 2010 at: 10/02/2020 10:33:51
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10/2/2020 10:00 AM	Rate (0)
qwazee Platinum Member Joined: 3/30/2020 Last visit: 4/19/2021 Posts: 1370 Rating: (365)	PISCEAN 2010 Set r0002 = r0024 @PISCEAN 2010: I have very little knowledge of the Siemens drives -- so you will have to help me here. Does the 'r' in 'r0002' not indicate it is a read-only parameter? Opening the 'r0024' parameter will have the drive display the output frequency - right? Can you configure the plug-in screen (BOP or other?) to display some values for you by default? GUWS Hi, i am using G120C VFD and i want to convert the Speed setpoint from RPM to HZ. i try to search in manual but i never found the exact one. please advise me. @GUWS: I ask some clarity for whomever follows up. Where does the "speed setpoint" come from? (analog / digital / comms / user input / pot / ..) Do you wish to only display the setpoint on theVFD screen or should the user be able to set the setpoint on the VFD screen? Which plug-in screen do you have? (BOP-2)
	ˢᵐᵃˡˡ ˢᶜᵃˡᵉ ᵖʳᵃᶜᵗᶦᵗᶦᵒⁿᵉʳ
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10/2/2020 10:13 AM	Rate (0)
GUWS Bronze Member Joined: 4/18/2014 Last visit: 3/26/2021 Posts: 241 Rating: (3)	PISCEAN 2010 GUWS Hi, i am using G120C VFD and i want to convert the Speed setpoint from RPM to HZ. i try to search in manual but i never found the exact one. please advise me. Set r0002 = r0024 Thanks Mr. PISCEAN, I tried, But its showing read only parameter

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10/2/2020 10:17 AM	Rate (0)
GUWS Bronze Member Joined: 4/18/2014 Last visit: 3/26/2021 Posts: 241 Rating: (3)	qwazee PISCEAN 2010 Set r0002 = r0024 @PISCEAN 2010: I have very little knowledge of the Siemens drives -- so you will have to help me here. Does the 'r' in 'r0002' not indicate it is a read-only parameter? Opening the 'r0024' parameter will have the drive display the output frequency - right? Can you configure the plug-in screen (BOP or other?) to display some values for you by default? GUWS Hi, i am using G120C VFD and i want to convert the Speed setpoint from RPM to HZ. i try to search in manual but i never found the exact one. please advise me. @GUWS: I ask some clarity for whomever follows up. Where does the "speed setpoint" come from? (analog / digital / comms / user input / pot / ..) Do you wish to only display the setpoint on theVFD screen or should the user be able to set the setpoint on the VFD screen? Which plug-in screen do you have? (BOP-2) Thanks qwazee, I am giving the Speed setpoint from HMI to PLC via profinet communication. My vfd part number is 6SL3210-1KE11-8UF2.

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10/2/2020 10:33 AM	Rate (0)
PISCEAN 2010 Platinum Member Joined: 4/23/2010 Last visit: 4/18/2021 Posts: 6552 Rating: (600)	qwazee PISCEAN 2010 Set r0002 = r0024 @PISCEAN 2010: I have very little knowledge of the Siemens drives -- so you will have to help me here. Does the 'r' in 'r0002' not indicate it is a read-only parameter? Opening the 'r0024' parameter will have the drive display the output frequency - right? Can you configure the plug-in screen (BOP or other?) to display some values for you by default? Hello, Please refer attached sheet for r0002 display values (dependency is r0046) which displays drive operation. As you pointed out correctly, its my fault. Attachment G120C r0002.jpg (39 Downloads)
	Last edited by: PISCEAN 2010 at: 10/02/2020 11:04:48
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10/2/2020 12:13 PM	Rate (0)
Technology Team Platinum Expert Joined: 10/11/2006 Last visit: 4/19/2021 Posts: 4746 Rating: (598)	Hello, the speed setpoint is transferred as a percentage value referred to p2000 and following parameters. So the easiest way would be to do the conversion on PLC side an provide the adequate setpoint in percent to the SINAMICS. Please see chapter 6.6.2 of the fieldbus manual for more details. https://support.industry.siemens.com/cs/ww/en/view/109757336
	With best regards, Technology Team Application consulting and pre sales support for SINAMICS, SIMATIC Technology, SIMOTION, SIMOTICS and MOTION CONNECT
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10/2/2020 3:55 PM	Rate (0)
0_Einstein Diamond Member Joined: 7/7/2010 Last visit: 4/15/2021 Posts: 10459 Rating: (1732)	Are you using a PLC or HMI connected directly to the drive to send the speed setpoint? If you are using a PLC, in the G120C telegram's 2nd word is where you put the speed setpoint scaled +/- 16384 for +/- 100% speed according to p2000. In p2000 in the G120C, reference speed, is the value that equals 16384. Use NORM and SCALE blocks together to take your RPM and convert it to +/- 100%. There are many examples of scaling the speed setpoint for use with a telegram in these forums as well as Siemens applications showing it being done automatically using TIA Portal SINA_SPEED instruction. GUWS Hi, i am using G120C VFD and i want to convert the Speed setpoint from RPM to HZ. i try to search in manual but i never found the exact one. please advise me.
	science guy
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10/3/2020 2:53 AM	Rate (0)
GUWS Bronze Member Joined: 4/18/2014 Last visit: 3/26/2021 Posts: 241 Rating: (3)	Thanks for all your support and help. Actually now the hz is working but if i enter the 10 HZ as setpoint from PLC, in vfd it showing as 13.5 Hz as a setpoint. If increase or decrease also the VFD setpoint value is not matching to my PLC setpoint. please advise.

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10/4/2020 7:36 PM	Rate (0)
zako_ Gold Member Joined: 5/22/2012 Last visit: 4/5/2021 Posts: 891 Rating: (63)	What is p2000 What is in r2050[1] if you use Telegramm 1 ?

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10/5/2020 3:16 AM	Rate (0)
GUWS Bronze Member Joined: 4/18/2014 Last visit: 3/26/2021 Posts: 241 Rating: (3)	zako_ What is p2000 What is in r2050[1] if you use Telegramm 1 ? Please find the attached document for your reference. And also i never found the r2050[1] in VFD Parameter. Thanks in advance. Attachment VFD.docx (23 Downloads)

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10/5/2020 8:16 AM	Rate (0)
jacek d Platinum Member Joined: 9/23/2005 Last visit: 4/19/2021 Posts: 3330 Rating: (524)	There's 38 entered as a reference speed. Therefore 38Hz - 100%. Because your maximum speed is 38 Hz as well, you can change a setpoint scaling in a PLC.
	Regards, Jacek What is confusing you is the fact that you never see a number but always its digit representation. So you end up thinking that the number is the representation. - Andrej Bauer Any claims against me - based on whatever legal reason - resulting from the use of any code and/or ideas presented on this forum shall be excluded.
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10/5/2020 11:30 AM	Rate (0)
GUWS Bronze Member Joined: 4/18/2014 Last visit: 3/26/2021 Posts: 241 Rating: (3)	jacek d There's 38 entered as a reference speed. Therefore 38Hz - 100%. Because your maximum speed is 38 Hz as well, you can change a setpoint scaling in a PLC. Thank u will check and update Actually the maximum speed is 38 rpm not Hz. If i change that 38rpm to 50 rpm means it should work ? why the maximum speed is in RPM instead of Hz? My rated Motor RPM is 38 RPM so i kept that the Reference speed in RPM and Maximum speed in RPM is same , whether is it right ?
	Last edited by: GUWS at: 10/05/2020 11:43:02 Last edited by: GUWS at: 10/05/2020 11:46:43 Last edited by: GUWS at: 10/05/2020 12:00:43
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10/5/2020 11:56 AM	Rate (1)
jacek d Platinum Member Joined: 9/23/2005 Last visit: 4/19/2021 Posts: 3330 Rating: (524)	My mistake. It should read RPM not Hz. A setpoint for a motor is in RPM. So you send 10 (RPM) therefore 10/38*50Hz = 13Hz. GUWS why the maximum speed is in RPM instead of Hz? Because Hz is not an unit of a rotational speed?
	Regards, Jacek What is confusing you is the fact that you never see a number but always its digit representation. So you end up thinking that the number is the representation. - Andrej Bauer Any claims against me - based on whatever legal reason - resulting from the use of any code and/or ideas presented on this forum shall be excluded.
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10/5/2020 12:10 PM	Rate (0)
GUWS Bronze Member Joined: 4/18/2014 Last visit: 3/26/2021 Posts: 241 Rating: (3)	jacek d My mistake. It should read RPM not Hz. A setpoint for a motor is in RPM. So you send 10 (RPM) therefore 10/38*50Hz = 13Hz. GUWS why the maximum speed is in RPM instead of Hz? Because Hz is not an unit of a rotational speed? Yes yes i calculate that thats why i asked as follows. My rated Motor RPM is 38 RPM so i kept that the Reference speed in RPM and Maximum speed in RPM is same , whether is it right ? If i change that 38rpm to 50 rpm means it should work ?
	Last edited by: GUWS at: 10/05/2020 12:11:08
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10/5/2020 2:23 PM	Rate (1)
0_Einstein Diamond Member Joined: 7/7/2010 Last visit: 4/15/2021 Posts: 10459 Rating: (1732)	Look in p2000 for reference speed. It is generally set to a convenient value for scaling, or for motor maximum rpm (same or higher than rated rpm, but usually higher). For example, many motors are rated at 1/2 or 1/3 of their maximum speed, especially inverter duty motors. For your specific situation, scaling the command setpoint so it is the correct proportion of the maximum speed to get desired speed. If p2000 is 100 rpm, 1% of 16384 (164) sent to the drive will give you 1 rpm. For 38 rpm, sending 6226 should give you the desired rpm (6225.9 <= 38.0/100.016384.0). Be sure and use NORM_X and SCALE_X in the PLC (s7-1200/1500) rather than using simple math instructions. Hope that makes sense. GUWS jacek d My mistake. It should read RPM not Hz. A setpoint for a motor is in RPM. So you send 10 (RPM) therefore 10/3850Hz = 13Hz. GUWS why the maximum speed is in RPM instead of Hz? Because Hz is not an unit of a rotational speed? Yes yes i calculate that thats why i asked as follows. My rated Motor RPM is 38 RPM so i kept that the Reference speed in RPM and Maximum speed in RPM is same , whether is it right ? If i change that 38rpm to 50 rpm means it should work ?
	science guy
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