Hi David,

This is a common question. Here is an old post regarding it:
http://www.cnczone.com/forums/dynomotion-kflop-kanalog/169493-kflop-external-servo-drives.html

The main difference is whether you want to close the position loop in
the individual drives and have basically an open loop system from the
perspective of the Controller (KFLOP), or have everything centrally
closed and tuned in the main Controller.

HTH
Regards
TK

On 12/18/2015 7:49 AM, david.m.stevenson@... [DynoMotion] wrote:
> DMM Dyn4 servo drives

Hi AZ,

Thanks very much for your detailed response. Until this project I have been using SnapAmp as the servo drive for Baldor servos, which is excellent at controlling the electrics. However, the present project requires a larger servo motor than the SnapAmp can accommodate, so I am pairing the KFlop with a Kanalog board to control the DMM drives. This is my first time using the DMM products.

The application is a metal rolling application, so it is somewhat forgiving with the positioning.

Interesting point about the disable input. I should have the system powered later today so I will definitely check that out to see if they've fixed it for the Dyn4.

Thanks again,
David.

 

David:

I would use the pulse input.  I haven't used their Dyn 4 but I used the predecessor, Dyn 3, in analog mode on another system and it was a nightmare.  The analog input had a 2 volt offset that had to be driven at some very noticeable current to 0 volt to stop the motor from turning at 2000 RPM.  ( a 1 K resistor to ground wasn't enough to bring the motor to zero speed).

The Dyn3 also they had a 20mv deadband so the final position wasn't achieved until you gave the integral gain time to overcome this deadband and pull it into position.  This would NOT be a good idea if you are milling or cutting in any way but is acceptable in point to point positioning if you have some time at the end of the moves to pull into position.  I don't know if they changed anything in this area of the circuitry but I would check with them before using analog for positioning. 

Another thing I noticed on the Dyn3 was when you disabled the amplifier with the logic disable input, it didn't really disable the amp.  It internally set the current command to "zero" which wasn't actually zero and you could hear and feel on the motor shaft that the power transistors were still firing just at a very low level.  In my world Disable on the amplifier means you stop all output transistor activity.

I hope this helps

AZ

Group: DynoMotion	Message: 12604	From: David Stevenson	Date: 12/18/2015
Subject: Re: Pulse vs Analog Servo Drive Input

Hi Tom, Thanks for the link to the forum. My understanding of the DMM system is it handles most of it's own tuning internally, but the servo drives have +/-ABZ encoder outputs which I am routing to the Kanalog. Hopefully this doesn't result in some kind of "clash of the Titans" operation. This project is basically a positioning application, but I have hopes of developing a torque-based application in the future using this system. Based upon your forum post it sounds like there may be some challenges to develop and tune that type of system. With best regards, David. On 2015-12-18 1:16 PM, TK tk@... [DynoMotion] wrote:   Hi David, This is a common question. Here is an old post regarding it: http://www.cnczone.com/forums/dynomotion-kflop-kanalog/169493-kflop-external-servo-drives.html The main difference is whether you want to close the position loop in the individual drives and have basically an open loop system from the perspective of the Controller (KFLOP), or have everything centrally closed and tuned in the main Controller. HTH Regards TK On 12/18/2015 7:49 AM, david.m.stevenson@... [DynoMotion] wrote: > DMM Dyn4 servo drives This email has been sent from a virus-free computer protected by Avast. www.avast.com

Group: DynoMotion	Message: 12605	From: Colin Fera	Date: 12/18/2015
Subject: Re: Pulse vs Analog Servo Drive Input

I am using the DYN 4 drives with .75kw motors on a milling machine. I attempted originally to use analog positioning in speed servo mode and had ok results at times but the drives were a bit difficult for me to tune as this was my first attempt at tuning analog servos. I instead tried pulse/direction and had better results and the drives were much easier to tune.  On Fri, Dec 18, 2015 at 11:53 AM, David Stevenson david.m.stevenson@... [DynoMotion] <DynoMotion@yahoogroups.com> wrote:   Hi Tom, Thanks for the link to the forum. My understanding of the DMM system is it handles most of it's own tuning internally, but the servo drives have +/-ABZ encoder outputs which I am routing to the Kanalog. Hopefully this doesn't result in some kind of "clash of the Titans" operation. This project is basically a positioning application, but I have hopes of developing a torque-based application in the future using this system. Based upon your forum post it sounds like there may be some challenges to develop and tune that type of system. With best regards, David. On 2015-12-18 1:16 PM, TK tk@... [DynoMotion] wrote:   Hi David, This is a common question. Here is an old post regarding it: http://www.cnczone.com/forums/dynomotion-kflop-kanalog/169493-kflop-external-servo-drives.html The main difference is whether you want to close the position loop in the individual drives and have basically an open loop system from the perspective of the Controller (KFLOP), or have everything centrally closed and tuned in the main Controller. HTH Regards TK On 12/18/2015 7:49 AM, david.m.stevenson@... [DynoMotion] wrote: > DMM Dyn4 servo drives This email has been sent from a virus-free computer protected by Avast. www.avast.com

Group: DynoMotion	Message: 12607	From: David Stevenson	Date: 12/20/2015
Subject: Re: Pulse vs Analog Servo Drive Input

Thanks Colin. I need to pickup a USB to serial converter for the connection before I can bring them online and check the tuning. Hopefully I can find one Monday. Best regards, David. On 2015-12-18 11:14 PM, Colin Fera colin.fera@... [DynoMotion] wrote:   I am using the DYN 4 drives with .75kw motors on a milling machine. I attempted originally to use analog positioning in speed servo mode and had ok results at times but the drives were a bit difficult for me to tune as this was my first attempt at tuning analog servos. I instead tried pulse/direction and had better results and the drives were much easier to tune.  On Fri, Dec 18, 2015 at 11:53 AM, David Stevenson david.m.stevenson@... [DynoMotion] <DynoMotion@yahoogroups.com> wrote:   Hi Tom, Thanks for the link to the forum. My understanding of the DMM system is it handles most of it's own tuning internally, but the servo drives have +/-ABZ encoder outputs which I am routing to the Kanalog. Hopefully this doesn't result in some kind of "clash of the Titans" operation. This project is basically a positioning application, but I have hopes of developing a torque-based application in the future using this system. Based upon your forum post it sounds like there may be some challenges to develop and tune that type of system. With best regards, David. On 2015-12-18 1:16 PM, TK tk@... [DynoMotion] wrote:   Hi David, This is a common question. Here is an old post regarding it: http://www.cnczone.com/forums/dynomotion-kflop-kanalog/169493-kflop-external-servo-drives.html The main difference is whether you want to close the position loop in the individual drives and have basically an open loop system from the perspective of the Controller (KFLOP), or have everything centrally closed and tuned in the main Controller. HTH Regards TK On 12/18/2015 7:49 AM, david.m.stevenson@... [DynoMotion] wrote: > DMM Dyn4 servo drives This email has been sent from a virus-free computer protected by Avast. www.avast.com This email has been sent from a virus-free computer protected by Avast. www.avast.com

Group: DynoMotion	Message: 12608	From: Colin Fera	Date: 12/20/2015
Subject: Re: Pulse vs Analog Servo Drive Input

A little side note with the dyn 4 drives.  Set the gains down as low as you can before you begin tuning. The default level the gains came with was way to high.  On Sun, Dec 20, 2015 at 6:30 PM, David Stevenson david.m.stevenson@... [DynoMotion] <DynoMotion@yahoogroups.com> wrote:   Thanks Colin. I need to pickup a USB to serial converter for the connection before I can bring them online and check the tuning. Hopefully I can find one Monday. Best regards, David. On 2015-12-18 11:14 PM, Colin Fera colin.fera@... [DynoMotion] wrote:   I am using the DYN 4 drives with .75kw motors on a milling machine. I attempted originally to use analog positioning in speed servo mode and had ok results at times but the drives were a bit difficult for me to tune as this was my first attempt at tuning analog servos. I instead tried pulse/direction and had better results and the drives were much easier to tune.  On Fri, Dec 18, 2015 at 11:53 AM, David Stevenson david.m.stevenson@... [DynoMotion] <DynoMotion@yahoogroups.com> wrote:   Hi Tom, Thanks for the link to the forum. My understanding of the DMM system is it handles most of it's own tuning internally, but the servo drives have +/-ABZ encoder outputs which I am routing to the Kanalog. Hopefully this doesn't result in some kind of "clash of the Titans" operation. This project is basically a positioning application, but I have hopes of developing a torque-based application in the future using this system. Based upon your forum post it sounds like there may be some challenges to develop and tune that type of system. With best regards, David. On 2015-12-18 1:16 PM, TK tk@... [DynoMotion] wrote:   Hi David, This is a common question. Here is an old post regarding it: http://www.cnczone.com/forums/dynomotion-kflop-kanalog/169493-kflop-external-servo-drives.html The main difference is whether you want to close the position loop in the individual drives and have basically an open loop system from the perspective of the Controller (KFLOP), or have everything centrally closed and tuned in the main Controller. HTH Regards TK On 12/18/2015 7:49 AM, david.m.stevenson@... [DynoMotion] wrote: > DMM Dyn4 servo drives This email has been sent from a virus-free computer protected by Avast. www.avast.com This email has been sent from a virus-free computer protected by Avast. www.avast.com