Controlling a 24V motor

I have a motion system with a PCI-7344 controlling several actuators through a MID-7654. I need to add one more axis. The actuator that I would like to use is only rated for 24V 0.2A. Is there a way to hook it up to the MID-7654 without overdriving it? I'm thinking of a voltage divider or some other small circuit. Or maybe there is a way to rig it for lower voltage that I am unaware of?
Any advice is appreciated.
Thanks,
Bob Young
Bob Young - Test Engineer - Lapsed Certified LabVIEW Developer
DISTek Integration, Inc. - NI Alliance Member
mailto:[email protected]

I don't see how series R would help.
In another thread I posted all the specs for my motor. They are:
24Vdc
200mA
1.19mH
54.6ohm
I have been working through the formulas presented here. According to this, if I increase the winding resistance (true, this is not winding resistance, but I would need to consider it as such) I increase the power that will be dissipated. True, most of the power would go through the resistor, but I think it would wind up being more than 5W.
To begin with, hooking up my motor in its raw state would yield:
di = (V/L)*dt = (48/.00119)*.00005 = ~2.0168amps ripple current
P=(I^2)*R_w = (2.0168^2)*54.6 = ~222Watts of power to dissipate.
I am a little sketchy on the current. If it set the limits to the minimum, (.85nom 1.7peak), will it use the ripple current of ~2a or the peak current of 1.7 in this formula? I assume the lower so
P=(I^2)*R_w = (1.7^2)*54.6 = ~157.8Watts of power to dissipate
This is still way too much for this fairly small actuator to handle.
With series R, I think that it would be the same formula for ripple current, but the power formula changes to
P=(I^2)*(R_w+Rseries) = (1.7^2)*(54.6+120) = ~505Watts of power to dissipate, with almost 350Watts being dissipated by the resistor. I either am not doing something correctly, or I would need a bigger resistor than a 5W one. And it won't help my motor.
I think I would need to have parallel resistance, thereby decreasing the winding resistance but I am not sure what happens with the inductance. I assume that it is largely unaffected. Rework the power dissipation formula to find the resistance R=P/(I^2). If I need to get the power down to about 5Watts, the resistance would need to be
R = 5/(1.7^2) = 1.73ohm which would take a parallel resistance of 1.7866ohms assuming that it did not affect the inductance much. Then I think you have problems obtaining a reasonable voltage through the motor V=IR = 1.7*1.73 = 2.941volts.
If I change the inductance without changing the resistance, I think it would change the ripple current without limiting the voltage. So I could increase the inductance (a lot) in order to reduce the ripple current to a value similar to the spec of the motor.
rework the formula di = (V/L)*dt to be L = V*dt/di and put in .2amp for di to get
L=48*.00005/.2 = .012 or 12mH. That would take about 11mH in series to bring the current down to spec. Then the power dissipation would be
P=(I^2)*R_w = .2^2*54.6 = 2.184Watts.
This whole thing has me quite confused however, so I might be wrong entirely. Can someone else run through my logic and numbers to make sure that I have not gone entirely insane . . .
Thanks,
BobMessage Edited by Bob Y. on 05-23-2005 11:58 AM
Bob Young - Test Engineer - Lapsed Certified LabVIEW Developer
DISTek Integration, Inc. - NI Alliance Member
mailto:[email protected]

Similar Messages

Controlling a 24V .2A motor

I had no answer on getting a MID-7654 to control a 24V, .2A servo, so I thought I would ask it a different way.
Is there any way at all to control a 24V, .2A servo through LabVIEW? I have found quite a few sites with stand alone controller/drivers, but I have not run across anything that will work for controlling this with labVIEW. Granted I could probably control one of those stand alones with serial commands, but I think that may be too slow for my application.
Another idea was to use a UMI-7774. Will the UMI-7774 do it alone or do I still need a driver/amplifier. If I do, any suggestions as to which one?
As you might have guessed, motion control is very new to me and this servo was requested by my customer, so I need some help making it work.
Thanks,
BobMessage Edited by Bob Y. on 05-17-2005 04:14 PM
Bob Young - Test Engineer - Lapsed Certified LabVIEW Developer
DISTek Integration, Inc. - NI Alliance Member
mailto:[email protected]

Bob,
you could control the 24V motor with the MID-7654 by adding inductances in series to the coils of the motor. Ideally the inductance should have the same ratings like the coils in your motor. This inductance would act like a inductive voltage divider but of course the drawback is the fact that 50% of the power is wasted in these additional inductances.
Probably a 3rd party drive would be a better solution. The UMIs are active breakout boxes for 3rd party drives and they add filtering and isolation but they don't drive power by themselves.
A lot of our customers use 3rd party drives in combination with NI's motion control boards. Typically those drives provide a command input (-10V to 10V) to connect to motion control devices like the NI-73xx boards. The serial port is used for drive configuration.
You might also have a look at our Drive Advisor. Here you can find a list of drives that have been tested with NI motion control boards. Some of them provide also direct connectivity to NI-73xx boards without the need of a UMI. I point out explicitely that there are many many more drives available that are not on that list but that work also perfectly with our boards.
Best regards,
Jochen Klier
National Instruments Germany

Controlling a 24V, .2A servo motor

I had no answer on getting a MID-7654 to control a 24V, .2A servo from the Motion Control and Motor Drives board, so I thought I would ask here.
Is there any way at all to control a 24V, .2A servo through LabVIEW? I have found quite a few sites with stand alone controller/drivers, and others for much smaller servos, but I have not run across anything that will work for controlling this servo with LabVIEW. Granted I could probably control one of those stand alones with serial commands, but I think that may be too slow for my application.
Another idea was to use a UMI-7774. Will the UMI-7774 do it alone or do I still need a driver/amplifier. If I do, any suggestions as to which one?
As you might have guessed, motion control is very new to me and this servo was requested by my customer, so I need some help making it work. Also budget is a consideration, but I will accept any suggestions.
Thanks,
Bob
Bob Young - Test Engineer - Lapsed Certified LabVIEW Developer
DISTek Integration, Inc. - NI Alliance Member
mailto:[email protected]

Good Morning,
The UMI-7774 is just an interface between the motion control boards and the power amplifier. The MID-7654 is basically just the power amplifier part of the list. Depending on your motor's requirements a controller out of the NI-73XX category might be a good fit with the 7654. The third party controller/drives can frequently be used, some, as you say, are serial communication, some are parallel (both interfaces are becoming harder to find). Remember, as to speed of communications, that motion controllers do some/most of the work. With many you specify a direction, distance and speed, and then they go off doing it, signalling when they're done with that motion. In some cases a series of complex motions can be downloaded and then initiated. There isn't a straight forward answer without more info on the application.
Sorry if this doesn't shed much more light!
Putnam Monroe
Senior Engineer, Certified LabVIEW Developer
North Shore Technology, Inc.
Putnam
Certified LabVIEW Developer
Senior Test Engineer
Currently using LV 6.1-LabVIEW 2012, RT8.5
LabVIEW Champion

Closed loop control of step motors possible with 7344?

Hi All
I have been looking around here for a while for an answer to this question.
For me, a closed loop control system is correcting for following errors all the time, also when the move is complete.
If the load on a system changes, there will often be a need for compensation in order to keep the position right. Then you need a closed loop control system.
I have made a system using DC motors with a 7342 controller. We are in the process og getting a new similar system, where the manufacturer chosed stepmotors in the believe that it can be used in closed loop.
Is it really true that the NI version of closed loop is only performing a what you call a "pull-in" at the end of the move in order to correct for lost steps or flexibility of the connection between motor and object/encoder?
I would call this "backlash compensation" or something like that.
Why dont you make a real closed loop option. The control voltage from your servo motor control, could be fed into a voltage-frequency converter with a matchin sign signal.
This shouldn't be too complicated to accomplish.
/b

You are right. NI motion control boards don't apply a control algorithm
during moves when configured in closed loop stepper mode. In this mode
the board monitors the following error during the move and generates an
error when the following error limit is exceeded and they start the
pull-in moves at the end of the move if necessary.
If you really want to do PID control with stepper motors you still
could connect an external V/f converter to the DAC outputs of the board
and control the axes like DC motor axes. Some vendors implement this
feature on their board but NI has decided not to do that as we don't
think that this approach provides a good solution. Here are some reasons:
The most important issue is the fact that you could easily exceed
the maximum rate of change of the motor frequency in the case that the
following error increases during the move. For a DC motor this would mean that the
voltage of the controller increases to compensate for this error and
the motor will follow - probably with some delay, but it will follow. For
the stepper this could mean that the acceleration becomes so high
that the motor stops immediately as it can't follow with a delay like a DC motor. What
should the controller do then? Restart the move automatically? Generate
an error? There is a big chance that you end up with a system moving in a stop and go mode.
The second issue is related to the control algorithm itself. The transfer function of a stepper motor is not really linear so it will be quite hard to find good tuning parameters. A DC motor can be tuned by analyzing the step response and the Bode plot. For the reasons that I have described in 1.) this won't work for a stepper so how should you tune it?
I have talked to some motion control engineers who have tried to control steppers with a PID algorithm and they all agree that this is a real pain and it's not recommended.
So if your system requirements involve online following error compensation I strongly recommend using a DC motor.
Best regards,
Jochen Klier
National Instruments Germany

What's the type of control for stepper motor?

Hi,
I'm using PXI-7358 controller, UMI-7774, Industrial Device NextStep third part microstepping drive, stepper motor SANYO-DENKI (type 103-8932-6421, NEMA42) and incremental encoder 3600 ppr (14400 count/round). I want to say what's the NI onboard type of control used to control motor step position? In the case of servomotor the type of onboard control is a PID, in the case of stepper motor what's the type of control? What's the MAX parameters to set for the project specific (overshoot, settling time, rise time etc..)? What does it means "Pull-in Window" e "Pull-in Tries" in MAX? So, it's possible control the stepper motor with user's algorithm control, excluding the onboard control?
Thanks for your patience,
Best regards
Lorenzo

>
Matt wrote:
> Go to SE24. Type in cl_dd_document and press enter. Select the methods tab. Look for the method "CONSTRUCTOR". Double click on it. Click on SIGNATURE button. The types of the parameters are clearly seen.
>
> matt
TYPE and VALUES OF TYPE -- different things. For example, TYPE C -- CHAR. VALUES of this: A, B, C, ..., 1, 2, 3.
Thus, return to question.
TYPES: sdydo_attribute(50) TYPE c
TYPE: sdydo_attribute
VALUES: ???
May be, value ABRAKADABRA correct?

How to control the step motor in this situation?

I have a PHI TRIFT3 ToF-SIMS instrument. The instrument comes with a default
software. However, the software don't offer fine step motor control. I want to control
the step motor using Labview.
I got some info from a Japanese engineer of the company.
The step motor controller is connect to a card in ISA slot. In the default software, I
can send command like D2000(distance 2000) and A100(acceleration 100) to "port 2"
to control the motor. I have a manual of the commands.
However, I don't know how to send command from Labview. Here is a joysticker
connected to COM1, COM2 is used for other vacuum control. The joysticker can also
control the motor..Here are some reply from the company about the control.
"We do not use special driver for control the step motor.
This is just sending the serial command via RS232C per command instruction I
sent you before. The only difference is, to simplify the hardware, we just talk to data acq
module(wave form card) via PAHOST card(installed in ISA bus slot of the PC)
to passthru the RS232C command to stepper motor control unit.
If you try to talk to step motor. just send the RS command from Labview
platform. (of course need to connect the step motor controller from PC,
default TRIFT PC does not have a spare COM channel, might be need to add
serial etension card or add the computer for Labview control)
"TRIFT PC passthru the RS232 command throught ISA bus to PHI data
acquisition box to stepper motor control.
Joystick handled by default software , convert to stage movement
command X and Y then send thru to ISA. "
I tried to use the Basic Serial Write and Read.vi to send command to COM1 but I always
get an error"1073807246 ocurred at property node(arg 1) in VISA configure Serial prot(Instr).vi->
Basic Serial Write and Read.vi Possible reason: VISA: the resource is valid, but VISA cannot access
it." I think this happens because the default software is also open and trying to control COM1.
What should I do to accomplish the step motor control? Thanks a lot

Just to start from scratch, have you verified that you can do basic communication with your serial port, ie successfully perform a loopback test? Please let me know, and we will go from there.
Logan S.

How to control 2 epos motor using microcontroller 50/5

Hi. i've done a program from epos integrated to labVIEW to control 1 epos motor. i do the program by using the given epos sub-vi to labVIEW, but i only know how to do for controlling 1 motor. Anyone can help me or tell me how to control 2 motors or wad is needed?? thanks for your help :-D
Solved!
Go to Solution.

Hi Spydi,
up to now, I never did it with two EPOS. But you should first check your setup with the EPOS-Studio. You need to set two different Node ID`s and after this works from the EPOS-Studio <you should do two seperate lines of programming in LabVIEW. I attach some VI`s from maxon which are simple in using for one EPOS. I assume you just need to program them in parallel.
And you don`t need the CANopen Library, it`s possible to use but very difficult. The EPOS-Library from the download is a Set of VI`s which where developed by maxon in Switzerland and free of use, they use a Communication DLL behind. If you`re interested maxon develops a new release right now. If you want to use them instead of the one you already had, let me know, I can ask there for a BETA and place it here at the forum.
Kind regards
Alex Rudolph
NI Switzerland
Attachments:
EPOS Module.zip ‏77 KB

Control a servo motor thru labview.

I want to control a servo motor thru labview. I have the following hardware: servo motor, electro-craft bdc-12, s8vm-15024 cd power supply, NI PCI-7831R, and scb-68 circuit board. I am new to the field and I have no idea how to connect the amplifier to the circuit board and create a program in labview to control the motor. Thank you for your help.

reposted here: http://forums.ni.com/t5/LabVIEW/I-want-to-control-a-servo-motor-thru-labview/td-p/1651742

How can I control 3 stepper motors w/ amplifier by sending TTL pulses from DIO96

We have NI PCI-DIO-96 board and we have 3 stepper motors with amplifier and encoders. We want to control the motors by sending TTL pulses directly from the DIO-96 board to the amplifiers. Is this possible? What would you recommend if this is not a good approach? Thanks in advance.
Roman Zeylikovich

Roman,
Thank you for contacting National Instruments. While using a motion controller would be the recommended approach for any type of motion application, you may be able to use your DIO board to generate a TTL pulse train to control the step and direction inputs of your drive and motor. You will need to make sure that the current sinking and sourcing specification for the DIO-96 fits your stepper motor. That board is not designed to source very much current at all so this is one issue you will need to verify. Also, this board does not have any counter/timer logic that can handle quadrature encoder inputs.
Again, this digital device is probably not the best solution to control a stepper motor, but, depending on your hardware, could be configured to work proper
ly. The PCI-7334 is a low-cost stepper motion controller that can control up to 4 axes and is designed to easily accommodate these types of applications. You can browse through more information on our Motion controller boards at the following website:
http://sine.ni.com/apps/we/nioc.vp?cid=3809〈=US
Let us know if you have any more questions or comments.
Regards,
Michael
Applications Engineer
National Instruments

Accelerometer sense tilt then interface with USB-6008 and generate PWM to control M995 servo motor

hi everyone,
currently im doing a final year project in LabVIEW using USB6008. my project involve of sensing the tilt from accelerometer and convert the tilt into PWM to control the turning of servo motor.
accelerometer that im using is ADXL322 which has Dual axis ±2g sense range
servo motor that im using is M995. when the servo motor in neutral position it required 1500microseconds, while it turns 90degree it requires 2200microseconds and whilw it turns -90degree, it requires 800 microseconds.
currently im facing problem in generating the PWM signal to control the operation of servo motor.
attachment is my VI design that i have done to date.
the program is about attracting tilt range from accelerometer using USB NI 6008 and then convert the tilt into angle in degree, and after that generate PWM to control two servo motor.
hopefully there is somebody can help me on this. thanks.
Attachments:
FYP.vi ‏253 KB

currently i need to generate PWM to control servo motor model MG995. but i am facing problem in generating the PWM in between 800usec to 2200usec to control the rotation of the servo motor. is there any example for me to refer.
below is my VI that i have done to date.
hopefully somebody can identify my mistake because my VI is not able to turn the servo motor.
Attachments:
pwm.vi ‏128 KB

How can I control 3 stepper motor in same time?

I want to control 3 stepper motor and 30 electro-valves.
I only had a few lessons on how to control one in C in college.
Now I need to do this in labview and using an board from NI
How can do the control of the three motors in same time?
What the best board to do this. Maybe the NI PCI 6034.
But I will need more than one?

At least some of the NI motor controller boards have up to 32 digital lines which can be set to input or output. I did not write the software for our systems but we are using quite a few of the digital lines for our systems and have no problems reading the digital inputs or setting the digital outputs. Also, the digital outputs offer a high current sink capability and usually can be used to drive external drives without any interface circuits.
The digital lines are available on a separate connector of the NI boards and there are also break-out boxes (with screw terminals) available. I do not see any serious problems to do your control tasks just with one NI motion controller board, as long as you do not have any special requirements (high sampling speed, high frequency pulse output etc) for the digital lines.

How can I control my step motor

I am using a 6006-DB 3-mothor driver and a NEMA step motor model 405-SM, both from AMSI corp. I would like to control my step motor using LabVIEW. We use the LV. 5.1.1 version and we have a PCI-MIO-16E-40 as adquisition card.
The sistem I want to built is to control my step motor and while turning detect the intesity variation on a photodetector which is conected to my adquisition card.
I wonder if somebody has an idea how to do that.
Thank you in advance
Daniel Hernandez

Ok I understood, I can use my PCI-MIO-16E card to control my steper motor driver, I will try to do that. But, if I use a DB-25 connector, how can I use my PCI card??
I was thinking to use the parallel port, directly, to conect my steper motor driver.
I attache some VI someone passed me. (It use a Setbit.vi and out port.vi)
Attachments:
MoteurGOTO6007-DB.vi ‏81 KB
MoteurGOTO.vi ‏87 KB
Commande_moteur.vi ‏10 KB

Amplifying the current of ni9264 for controlling a DC motor in both directions:

I want to control a DC motor in both directions by NI9264. The problem is the module can not provide enough current.
It is easy to amplify the current by a "common collector powr transistor" for 1 direction, but how can I make it reversible?
p.s. It does not matter if I use one port with +/- 10v or two different ports for one mottor.
Thank you for your answers in advance.

Navid,
typically DC motors are not driven by a proportional current signal, but by a PWM signal which is provided by an H-bridge circuitry that allows bidirectional moves.
So you either could use an external power drive, that accepts a +/-10 V input signal from the NI 9264 or you could replace this module with an NI 9505, that has a powerful H-bridge circuitry built in in addtion to quadrature encoder inputs, which are typically required for a motion control application, too.
Please note, that the NI 9505 can only be used in a cRIO chassis but not in a cDAQ chassis. In general for a motion control application should be done with a cRIO system and not with a cDAQ system, as you won't be able to run a stable and deterministic control loop with a cDAQ system.
Kind regards,
Jochen Klier
National Instruments

Controlling a small motor

Hello everyone,
I have a small and probably dumb problem I cannot seem to find a solution
for: I need a PCI board to control a small 24V, 3.5W max motor used to
rotate a piezo transducer.
The kind of control I need over the motor is very basic (on/off and little
else), the only requisite is that it can be controlled via software
(preferably labview).
In the future the system will be upgraded to a stepper motor (for which I
found many PCI-based options), but for now we're stuck with this one.
Any suggestions would be greatly appreciated.
Thank you
Marcello Barboni

Hi Marcello,
You need a Metrabyte Compatible I/O Card. The PCL725
was the most famous version of it.
I have used the following card from CyberResearch with phenomenal success
CYPDISO8 8 Mechanical Relays, 8 Isolated Inputs Board
This is a PCI Card with 8 Relay Outputs, which can be individually controlled. They will Handle your Motor Ratings. Unfortunatley the Data Sheet can be Obtained by Fax-On-Demand Only.
If you are not bent on PCI interface, there is another ISA card that will do the job and it is even cheaper.. $150.00 max.
CYDO 24HV/48HV High-Voltage, Direct Drive Digital Output Boards. These will Handle directly 50V/0.5A load. With Motor make sure you include a Freewheel diode to curb the transients.
http://www.cyberresearch.com/fod/fod5315
.pdf
Check www.cyberresearch.com
The Only drawback is that you have to purcahse the drivers seperately for about $50.00. They do have ready LabView Drivers.
http://www.cyberresearch.com/fod/fod6021.pdf
Good Luck!!
Mache
Good Luck!
Mache

How can I control a dc motor speed using an optical switch?

I am trying to use LabVIEW to create a VI that controls the speed of a DC motor. The system needs to have an user set rpm and the DC motor needs to adjust the duty cycle to obtain the correct rpm dependant on the load. A disk with holes and an optical switch is being used to measure rpm.
The current problem is that I cannot get the rpm based on the optical switch.
Thanks for your help!
Attachments:
Speed reg.vi ‏183 KB

The error for the samples to write does not appear after redoing the vi. Thanks. The controller seems to be working mostly.
However, the issue with the Tone Measurement reading inaccurately at low frequencies still exist. Any ideas?
I have attached the latest vi.
Thanks again!
Attachments:
speed_reg_v2013-05-07.vi ‏183 KB

Controlling a 24V motor

Similar Messages

Maybe you are looking for