NI pci 6251 position control

Hi
Im new to this forum and new to Labview and NI pci 6251 as well ;(
I'm using NI-PCI-6251 (DC Motor ) with Labview to control the position of a DC motor we developed the program that reads the encoder and display the position of the DC motor shaft
but the problem is that the counter 0 (cnt0) always increases whether the disc rotating clockwise or anticlockwise??!! and when the desired position is reached the controller does nothing to stop the motor ?
i don't know what is the problem or why its happening.

Hi,
I am also doing something similar.
The problem is the motor is the DC motor from Quanser. (DCMCT).
I know the encoder channel of the motor is ctr0 and when I test from "Measurement and Automation Explorer" (Labview>>Tools) I can only read the PFI8 channel.
The motor read 4096 pulses per revolution and no reading is available from PFI10. As per Quanser the motor should be about to do position control. I have seen lab tutorials for position control in internet.
I tested both the vi is mentioned above. The "Example" vi reads the motor position in terms of pulses. But when I rotate the motor in the other direction the count increment not decrement.
Also the quadratureencoderMseries vi did not read the angle position when I set the channel values.
I have attached the parameters that I set.
Can any one please check..
Thanks.
Attachments:
encoder issue.JPG ‏357 KB

Similar Messages

Position Control of compumotor linear servo table and GV-U6E with PCI-7344

I'm referring PCI-7344 (not 7334).
I have the GV-U6E which is a drive only and does not possess control functionality. the drive only version does not store or use programs. So, serial commands can not be sent through COM port by LabVIEW even though A few basic commands can be emulated.
I am trying to do position control as I mentioned. For example, the motor should move A point to B point exactly with a certain speed. The points must be aboulte position.
I would like you to see the reference comment that I have been contacting with in your website forum.
http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RPAGEID=135&HOID=506500000008000000DD490000&USEARCHCONTEXT_CATEGORY_0=_14_&USEARCHCONTEXT_CATEGORY_S=0&UCATEGORY_0=_14_&UCATEGORY_S=0
Regard,
Jin Ho Lee
----- Original Message -----
From:
To:
Sent: Thursday, September 26, 2002 5:00 PM
Subject: Re: (Reference#1549-QYW196) "Position Control of linear servo table and GV-U6E with PCI-7344
>
> Note: Your reference number is included in the Subject field of this
> message. It is very important that you do not remove or modify this
> reference number, or your message may be returned to you.
>
>
> JinHo. Compumotor is a very popular brand, and I know of several customers
> who integrate our 7334 with Computmotor drives. However, when you say that
> the MAX configuration doesn't fit in the compumotor drive settings, are you
> referring to the specs from the 7344? It looks like the 7344 and the
> Compumotor will work well together through a UMI break out box. If you're
> referring to specific commands that the Compumotor receives, I'd have to
> know more about the protocol. If the Compumotor needs serial commands,
> then you can send them through the computer's COM port from LabVIEW.
> Please let me know exactly what kind of configurations you're trying to
> set. The 7344 can be completely configured in MAX and LabVIEW.
>
>
> Best Regards
>
> Kyle Voosen
> Applications Engineer
> National Instruments
> http://www.ni.com/support
>
> ------------------------------------------------------------------------------
>
> Problem Description :
> "Position Control of compumotor 406LXR linear servo table and GV-U6E(motor
> drive) with PCI-7344"
>
> "Since I had the answers referring:
> http://exchange.ni.com/servlet/ ProcessRequest?RHIVEID=101&RPAGEID=135&
> HOID=506500000008000000DD490000& USEARCHCONTEXT_CATEGORY_0=_14_&
> USEARCHCONTEXT_CATEGORY_S=0& UCATEGORY_0=_14_&UCATEGORY_S=0
>
> Wiring step was done well. However, I still have a problem that MAX
> configuration doesn't fit in compumotor drive settings. Therefore, the
> setup is shown below, and I want to know how I can set up PCI-7344
> configuration in MAX or LabVIEW VI.
>
>
> -----------------------------------------------------
>
> Uploaded from device address 0
>
> Gemini GV Servo Drive Setup
>
>
>
> Motor Setup
> DMTR 1703
> Motor ID (406-x-LXR-M-x-D13-x-x-x-x-E5-x-x-x)
> DMTIC 2.48
> Continuous Current (Amps-RMS)
> DMTICD 0.00
> Continuous Current Derating (% derating at rated speed)
> DMTKE 17.6
> Motor Ke (Volts (0-to-peak)/krpm)
> DMTRES 10.10
> Motor Winding Resistance (Ohm)
> DMTJ 119.300
> Motor Rotor Inertia (kg*m*m*10e-6)
> DPOLE 1
> Number of Motor Pole Pairs
> DMTW 40.5
> Motor Rated Speed (rev/sec)
> DMTIP 7.40
> Peak Current (Amps-RMS)
> DMTLMN 3.4
> Minimum Motor Inductance (mH)
> DMTLMX 3.4
> Maximum Motor Inductance (mH)
> DMTD 0.000000
> Motor Damping (Nm/rad/sec)
> DMTRWC 0.23
> Motor Thermal Resistance (degrees Celsius/Watt)
> DMTTCM 20.0
> Motor Thermal Time Constant (minutes)
> DMTTCW 0.33
> Motor Winding Time Constant (minutes)
> DMTAMB 40.00
> Motor Ambient Temperature (degrees Celsius)
> DMTMAX 90.00
> Maximum Motor Winding Temperature (degrees Celsius)
> DHALL 1
> Disable Hall Sensor Checking
> DMTLQS 0
> Set Q Axis Inductance Saturation
> DMTLDS 0
> Set D Axis Inductance Saturation
> DTHERM 0
> Disable motor thermal switch input
>
>
>
> Drive Setup
> DMODE 2
> Drive Control Mode
> DRES 8400
> Drive Resolution (counts/rev)
> DPWM 16
> Drive PWM Frequency (kHz)
> SFB 1
> Encoder Feedback
> ERES 8400
> Encoder Resolution (counts/rev)
> ORES 8400
> Encoder Output Resolution (counts/rev)
> DMEPIT 42.00
> Electrical Pitch (mm)
> SHALL 0
> Invert Hall Sensors
> DMTLIM 1.5
> Torque Limit (Nm)
> DMTSCL 1.5
> Torque Scaling (Nm)
> DMVLIM 119.000000
> Velocity Limit (rev/sec)
> DMVSCL 119.000000
> Velocity Scaling (rev/sec)
>
>
>
> Load Setup
> LJRAT 0.0
> Load-to-Rotor Inertia Ratio
> LDAMP 0.0000
> Load Damping (Nm/rad/sec)
>
>
>
> Fault Setup
> FLTSTP 1
> Fault on Startup Indexer Pulses Enable
> FLTDSB 1
> Fault on Drive Disable Enable
> SMPER 8400
> Maximum Allowable Position Error (counts)
> SMVER 0.000000
> Maximum Allowable Velocity Error (rev/sec)
> DIFOLD 0
> Current Foldback Enable
>
>
>
> Digital Input Setup
> INLVL 11000000
> Input Active Level
> INDEB 50
> Input Debounce Time (milliseconds)
> INUFD 0
> Input User Fault Delay Time (milliseconds)
> LH 0
> Hardware EOT Limits Enable
>
>
>
> Digital Output Setup
> OUTBD 0
> Output Brake Delay Time (milliseconds)
> OUTLVL 0100000
> Output Active Level
>
>
>
> Analog Monitor Setup
> DMONAV 0
> Analog Monitor A Variable
> DMONAS 100
> Analog Monitor A Scaling (% of full scale output)
> DMONBV 0
> Analog Monitor B Variable
> DMONBS 100
> Analog Monitor B Scaling (% of full scale ouput)
>
>
>
> Servo Tuning
> DIBW 1500
> Current Loop Bandwidth (Hz)
> DVBW 100
> Velocity Loop Bandwidth (Hz)
> DPBW 40.00
> Position Loop Bandwidth (Hz)
> SGPSIG 1.000
> Velocity/Position Bandwidth Ratio
> SGIRAT 1.000
> Current Damping Ratio
> SGVRAT 1.000
> Velocity Damping Ratio
> SGPRAT 1.000
> Position Damping Ratio
> DNOTAF 0
> Notch Filter A Frequency (Hz)
> DNOTAQ 1.0
> Notch Filter A Quality Factor
> DNOTAD 0.0000
> Notch Filter A Depth
> DNOTBF 0
> Notch Filter B Frequency (Hz)
> DNOTBQ 1.0
> Notch Filter B Quality Factor
> DNOTBD 0.0000
> Notch Filter B Depth
> DNOTLG 0
> Notch Lag Filter Break Frequency (Hz)
> DNOTLD 0
> Notch Lead Filter Break Frequency (Hz)
> SGINTE 1
> Integrator Option
> SGVF 0
> Velocity Feedforward Gain (%)
> SGAF 0
> Acceleration Feedforward Gain (%)
> -----------------------------------------------------
>
>
> Regards,
> JinHo"
> NI Software :
> LabVIEW version 6.0
> NI Hardware :
> Motion Control device PCI-7344
> Driver Version :
> no
> OS :
> Windows 2000
> CPU :
> Pentium
> RAM :
> 128
> Vendor :
> DELL
> Customer Information :
> Jin Ho Lee
> North Carolina State Univ.
> US
> [email protected]
> Ph: (
> 919
> )
> 512-9929
>
>

Yes, we used an NI PXI-7344 motion control card with an NI UMI-7764 box connected to a Gemini GV-U12E servo drive. (which is a drive only.)
We did positional control in absolute position mode.
I can send you an AutoCAD schematic detailing how to connect the UMI-7764 to the Gemini GV servo drive.
In regard to the Rs232 interface to the GV servo drive,
the GV drive only model is "configurable" not "programmable". You can create unique GV configuration files with Compumotor's Motion planner then download the configuration via Rs232 using LabVIEW as desired. Or, using LabVIEW via Rs232 you can change individual GV drive parameters on demand,
or use the GV's two analog outputs back to LabVIEW's analog inputs to measure commanded motor current or torque, etc.etc.etc

Brushless DC motor control using NI PCI 6251

am doing my project Speed control of a sensored Brushless DC motor. am using NI pCI 6251 daq. now my motor is running.but i dont know how to calculate the speed. in BLDC motor, hall sensor is attached. can you send me the sample program for calculating the speed and to give as a feedbackk

Will you please sent me VI model of BLDC ?
my mail id: [email protected]

Closed loop control of DC motor drive using PCI 6251

Hi
i am using NI PCI 6251 for closed loop control of dc drive.(shunt motor,220v, 0.5HP, 2.5A rated, 1500RPM)
the dc motor is fed from a bidirectional dc-dc converter. this converter works in boost mode(forword motoring) and buck mode(braking mode/battery charging)
the converter is built using mitsubishi IGBT module. at low voltage side of the converter a battery bank of 48V is connected and high voltage side the motor is connected.
An IR sensor is developed to measure the speed of the motor and a hall current sensor is used to sense the converter current.
in the control part i have an inner current control loop(PWM controller) and a outer speed control loop.both controllers are PI controller. To measure the speed i have used counter of the DAQ assistant, then frequency. then this frequency is converted to RPM using labview.after giving the speed and current signals to the controllers , then i started tunning the PI gain, but at the starting the duty cycles was 100%, so the IGBT got damaged immediately. now how to tune the controllers during the closed loop operation. the switching frequency of the converter is 20KHz.
can any body suggest me how to run the dc drive in closed loop ?
thanking you.

Hi Premenanda
The freq data receiverd from the daq assistant has the units of Hz, or in terms of motor speed, rps (rotations per second). I can see that you are trying to convert that to rpm (rotation per minute). which can be done by dividing the rps speed by 60. Instead, you are multiplying it by 60 and also comparing with 2000. the resultant multiplied value is displayed in your program only if it is smaller than 2000.which is causing the problem here.( as seen in file 'original code.png)
I have attached a file named 'modified code.png' that shows how the conversion from rps to rpm is done. Please do the required changes in your code and let me know if it works.
Attachments:
modified code.png ‏18 KB
Original code.png ‏15 KB

Analog Fedback for position control

Hi all,
Its been a long time since I have written into this discussion forum. I have a question. Till now I have been using encoder as a feedback device for position control in PCI 7342 motion controller. Now I want to know about position control using the analog input channel. I cant figure out how the controller understands the equation between input voltage and position.
Say X Volts = How many mm of movement?
With the encoder f/b the motion controller knows the encoder pulse per revolution and it keeps counting the feedback and generates motion accordingly. How is it done with analog feedback. My application involves an LVDT which give proportional analog feedback with respect to the displacement. Please help me oiut on this. Also is position compare and breakpoint feature relevant to this particular problem?

Hi Giridhar,
it's good to see you back in the forums.
I have posted a document to another thread that contains a detailed description of the analog feedback feature.
I hope that helps,
Jochen Klier
National Instruments Germany

Pci-6251 soprta tiempo real

Buen día:
Quiero implementar un control de velocidad de un motor de cd en tiempo real, cuento con una tarjeta PCI-6251, el sensado de la velocidad es un encoger incremental.
Preguntas:
¿La tarjeta PCI-6251 soporta el tiempo real?
¿Existe algun ejemplo para estudiar su implementación?
Cuento con LabVIEW 8.0 y tengo instalado el modulo Real-Time.
Tengo algunos problemas con el tutorial Real-Time.
Gracias de antemano.

Estimado itlcarlos
Gracias por utilizar los foros de National Instruments.
En primera instancia quisiera entender a lo que te refieres con "Tiempo real", ya que tiempo real indica que estarías trabajando bajo un sistema operativo determinístico con el cual te asegurarías que existe confiabilidad total en el sistema, de ser así no podrías trabajar en Windows ya que no es determinístico. Si intentas ver la tarjeta como un dispositivo RT no va a ser esto posible en el proyecto de LabVIEW.
Ahora si te refieres con Tiempo Real a que la tarjeta trabaje de manera confiable y envíe la información en tiempo y forma al sistema operativo, te sugiero revises la hoja de especificaciones para que determines si la precisión y el reloj son suficientes para tu aplicación
Me gustaría me aclararas si esa era tu pregunta o me detalles un poco más que es lo que intentas hacer y con todo gusto te ayudaré.
También dime que problemas tuviste con el tutorial de Real Time para ver en que te podemos ayudar.
Que tengas un excelente día.
NI 625x Specifications
http://www.ni.com/pdf/manuals/371291h.pdf
Coamín Cruz
Ae México

Programar con labview una pci-6251 para que ésta me genere una señal

Hola a todos. Veréis tengo un problema; hemos adquirido una pci-6251 y necesito programarla con labview 8.0 para que me genere una señal (en concreto, una chirp o un pulso), podría alguien como puedo hacerlo???

Muchas gracias!!!! Ya he conseguido generar mi chirp. Ahora tengo otro problema necesito poner tres controles, uno para poner la chirp a la frecuencia que yo quiera, otro para indicar su longitud y otro para indicar su ancho de banda.
Adjunto el programa para ver si vosotros sabeis cómo puedo añadirle estos controles. Gracias por vuestra ayuda!!!!
Adjuntos:
generacionchirp1.vi ‏62 KB
generacionchirp11.vi ‏62 KB

PI controller with PCI 6251

Hi all,
I am using DAQ PCI6251. Can I use this card for creating PI controller ?
Basically, I think that we can analyze a PI controller into two phases, including the proportional and integral phases. I could do this easily with Labview library. But I am facing a difficulty how to build the saturation block for PI controller ?
Pls give me the solution.
Thanks so much for your helps and supports.
Best regards,
Duy

Dear Jochen,
Thank you very much for your reply.
I can describe what I am doing as follows:
I would like to control the induction motor drive system with vector control approach.
The equipments in my system include the induction motor drive system, inverter, PCI 6251 Labview card, block connector BNC2110. I am using Labview 7.1.
I will gather the stator currents and voltages from the induction motor under analog signals. Then I will make some calculations on Labview with available Labview library. After that I will output two analog signals. PCI 6251 has two analog signals. I will use two analog signals from PCI6251 Labview card as input signals for PWM generating board which I could bulid. This PWM generating board will create signals to trigger IGBTs of inverter. And the inverter will create signals to control the induction motor drive system.
In this drive system, we need to use two PI controller as the requirement of vector control approach.
I hope that my description is clear.
The expected sample rate is 10 kHz.
I am using XP Window OS.
I attach the diagram what I need to do as well.
Thanks so much for your great ideas.
Best regards,
Duy
Attachments:
Practical_diagram_Labview_NI.pdf ‏27 KB

PID in PCI-6251

Hi All
i'm need to control solenoid valve by DAQ PCI-6251,but i'm don't have PID toolkit in program.
how i do to PID wihtout PID toolkit.
best regard
zacha

I guess it really depends on what you are trying to do. If you truly are trying to do PID then my suggestion is buy the PID toolkit, it will save you time in the long run. Of course, if you don't want to do that, then you are going to have to come up with the math on your own which could be challenging. If really all you want to do is turn on and off solenoid valves then perhaps just writing to the digital lines will be enough for your application. Those are the best thoughts I can suggest.
StuartG

PCI-6251 into LABVIEW DAQ Assist block interruptions and resets

Signals being received from PCI-6251 into a LABVIEW DAQ Assist block interrupts and resets every 10 seconds after 1 minute of data acquisition. Would this be a memory buffer problem or is it something related to the hardware? I am using a BNC-2110 hardware connector. Please view the attached image.
Attachments:
Interuption1a.GIF ‏4 KB

Hey Peter,
Ahh, I understand the graph now! Hmm, this is very strange behavior. Instead of using the DAQ Assistant, try to use the explicit DAQmx VIs (see picture). You have more explicit control over what is going on with the DAQmx VIs and keep as much as you can out of the loop.
Regards,
Erik
Attachments:
analoginput.JPG ‏23 KB

Problem in edge separation measurement by using NI PCI 6251 card

I am trying to measure time delay between two TTL pulses (rising edge of the first signal and falling edge of 2nd signal) generated by two Photo detectors (APD) . These pulses are random pulses. Pulse width is 20ns and height is 2.5 volt at 50 ohm termination. I am using NI PCI 6251 card (M series card) for this job. I have attached my program and DAQ assist settings using for this job to this mail. Problem is   6251 card couldn't detect the pulses from APD. Exactly error shown is
                                                         "Error 200474: specified operation did not complete because the specified timeout expired".
I have tried by increasing the waiting time but it didn't solve the problem. I have tested my program with 20ns pulse width TTL pulses which are generated by a function generator, in this case my program worked well and given expected result.[both the signals are from same function generator and they are synchronized so edge separation measurement gives width of the pulse ] The height (voltage) of the TTL pulse generated by the function generator is 4v at 50 ohm termination. Is this height difference creating the problem? What can be the reason ? Can anyone suggest a better way to do this job.
                                                                                 Thanks in advance
                                                                                                                                                                                                                      Regards
                                                                                                                                                                                                                       surya
Research student
Attachments:
daqassist.jpg ‏71 KB
edgeseparatio.jpg ‏26 KB

Hey JmBone,
It's possible that you are just suppose to send a 32-bit integer to control the 32 valves. The 'byte offset' is probably just there to allow grouping of 8 valves (8 bits as 1 byte). So instead of sending an 8-bit number with some offset, you just send a 32-bit number and only change the bits corresponding to the valves you want to change. It would be easiest to just have a 32-bit binary array in your code for changine the individual valves and then cast that to a U32 integer before sending it to the Set Attributes VI. Maybe I am misunderstanding the manual, but I don't think 'byte offset' is a parameter you are suppose to specify, and is just there to indicate how the valves can be bundled into a single 32-bit value.
Regards,
Ryan

Data acquisition and frequency generation togather with PCI-6251 and LV8.2

Hi friends,
I am a new user of Labview. I am using LB8.2 with PCI-6251 .
I have to generate frequency and then measure the data and then for next frequency and so on.
i know that for this i have to use looping and that is not a problem. The real problem for measurement is to identify whether the frequency is been generated. if yes then measurements starts otherwise it should wait until it started. then after finishing the measurements send a signal to generator for changing the frequency and amplitude.
Now these two things {generation and measurement} togather are not working correctly for me. so i make 2 diff file, one for generation and other for measurements <by modifying the examples>. I can run both file togather and it works. But it need lots off effort and time. I have to measure from 10Hz to 1000Hz in 2Hz frequency step and i cannt leave in between .
can anyone help me how to syncronize these two togather .
Trying to attatch. both the files here ..
main_v1.1.vi --> for Measuring
Oscilloscope.vi --> for waveform generation
Attachments:
main_v1.1.vi ‏150 KB
Oscilloscope.vi ‏37 KB

Hay thnx dude..
I found the example and now it works
once again thanks a lot

How to generate a pulse of 5 V -ve polarity in synchronisation with a 10 v input using PCI 6251 DAQ board

HI
I want to generate a 5V -ve polarity pulse to trigger my IEEE 1394 camera using an PCI 6251 (scb68 pin E) device, furthermore I am reading a standard Vsync signal from a SVGA port which is 10 v.
Now I want to synchronise the image capture of an IEEE 1394 camera with the Vsync signal so that camera is triggered to capture at every 4th Vsync signal (which is 50HZ.). Presently I am able to read the Vsync signal and also generate the -5 v signal But the Daq board generates a continues -5v signal while I want a 1 ms pulse (for every 4th Vsync).
Also this 5 v signal is generated even if the vi is stopped running.
Can anybody guide me so this problem can be solved.
Thanks a lot in advance
Shri

You can use the Write function, that is you can use the 10 volt signal as a trigger for the task, and when you get this trigger, the task starts and generate (writes) a waveform you defined in an array ("data", in the example).
Something like this..
DAQmxCreateTask("",&taskHandle);
DAQmxCreateAOVoltageChan (taskHandle, clokSource, your_sampling_freq, -10.0, 10.0,
DAQmx_Val_Volts, "");
DAQmxCfgSampClkTiming (taskHandle, clockSource, SAMPLING_RATE,
DAQmx_Val_Rising, DAQmx_Val_FiniteSamps,
samp_to_read);
DAQmxCfgAnlgEdgeStartTrig (taskHandle, input_channel, DAQmx_Val_RisingSlope, 9.0);
DAQmxWriteAnalogF64 (taskHandle, 1000, 0, 10.0,
DAQmx_Val_GroupByChannel, data, //data contain a pulse
&samp_per_channel, 0);
DAQmxStartTask(taskHandle);
// and then you create a loop....
For example you can specify data to be like this:
data[0] = -5;
for(i=1;i<1000; i++){
data[i] = 0;
Tell me if you need more help.....
bye

How do I handle a count overflow while running "end's" rotation drive in position control?

Hi everyone!
We run a direct drive in position control mode and normally do oscillating movements i.e. +-10°. The Signal we get is a TTL with 120 counts/°. And with those counts we do our control.
But now we want to run the motor permanent one direction for some days (or 4 ever :-). That means that we get sooner or later a overflow on the count variable. So I think we have a problem when the setpoint is on Overflow -32767 and the Position is 32767. ( I know that I can increase the Integer Value but that does not solve it at the end :-)
How can I handle that?
Is there any programmatic approach?
Thanks for Help!

Hi Petric,
I do see the math but that does not help when I have more then one overflow, right?
Well, you have to make sure you NEVER miss such an overflow event. It would be a big problem if you would detect just every second overflow…
I got a big issue when the setpoint is jumping due to overflow! I have to handle that primarly.
Have your control loop work with arbitrary units.
Convert your measurement signal to arbitrary unit with handling overflows in this step.
Convert your control output to output signal handling overflows as well…

How to trigger 5v -ve polarity from pci 6251 to sincronise the image capture

Hello!
I want to synchronise the image capture of an IEE 1394 firewire camera with an 50hz input signal (acquired from Vsync of VGA port ). I want to accomplish this using PCI 6251 (SCB 68 E series) device. The IEE 1394 camera can be triggered using a 5V –ve polarity signal but have no idea how it is achieved, some examples about the application would be helpful
shri

This example illustrates how an application might be constructed in order to trigger an analog acquisition as well as an external system concurrently with an E-Series board. The analog component has been made retriggerable by tying a counter pulse train to its sample clock. Due to the complexities of the DAQ STC, an analog output line is employed in order to generate a hardware-timed, regular, pulse used to trigger both the analog acquisition, and potentially an external system. This type of architecture could be used for "stimulous - response" testing.
Attachments:
Timing_with_AO.vi ‏123 KB

NI pci 6251 position control

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