Minh Pham
-
Posts
171 -
Joined
-
Last visited
-
Days Won
3
Content Type
Profiles
Forums
Downloads
Gallery
Posts posted by Minh Pham
-
-
-
QUOTE (harika @ Nov 24 2008, 09:28 PM)
I did post before regarding to this problem. This is a duplicated issue from you earlier:
http://forums.lavag.org/xy-graph-t12439.html
XY graph requires array of dat (set of points(xi,yi), not 1 point as mention in the reply above.
Check the context help when working with function that you are not familier, check detail help of the function to see example.
-
QUOTE (Fresnel @ Nov 22 2008, 01:21 AM)
I have an image of a spot on a CCD camera and it is a fairly stable image. I have a lot of background noise around the image I'd liketo cut out. I can do this easily using an Intensity graph to work out what pixel values to ignore but I'd also like to only analyse a rectangular
segment of my whole image, ie a rectangle around the spot.
I have tried using IMAQ select rectangle but it just keeps constantly asking me to select a rectangle even after one is selected.
Any ideas?
How did you implement IMAQ select rectangle in your code? It is easier to see the structure/architect of your code before i can comment anything.
However, I have a feeling that you are having this function in a loop or some sort, be careful on dataflow in LabVIEW.
Below is a simple example on how you can set the window position, dont forget the window number:
-
have a look at i2dx's ADO-Tookit
http://forums.lavag.org/my-ADO-Toolkit-for...EW-8-t2482.html
Simple and easy to use, with some understanding of SQL should be great.
Good luck,
-
have a look at i2dx's ADO-Tookit
http://forums.lavag.org/my-ADO-Toolkit-for...EW-8-t2482.html
Simple and easy to use, with some understanding of SQL should be great.
Good luck,
-
This is probably not the right way of using inplace element. It is design for working with element/structure which has the same size at both the input and output. Operations such as modifying data element within array, swap data between array indexies...without creating an extra memory
buffer, hence performance is improved.
Building a new array based on the data from the inplace element (IPE) input node will not help as you are increasing the size of the IPE output, as the result, LV still has to organize buffer for the operation described.
-
-
I would think you had better to create your own Character Set for your application, every application is different in many different ways. Talking about the Character Recognition, each font type has different set of characters itself. So i believe you would need to train the system as much as you can so that the character set is well recognized by the System.
VIsion is all about images so all of the important factors like clear, brightness, contrast, distance taken etc... need to take into account while creating your character set, the better you train your system, the better its intelligent in recognizing things. Just like us, without training ourselves we wouldnt be able to recognise many different objects.
The training tool in Vision quite simple to use, play around with parrametters while creating your Character Set to achieve better results.
Good luck
-
QUOTE (Phillip Brooks @ Nov 20 2008, 07:30 AM)
I make balloon animals to distract them
Lol,
This remind me the time I teach LabVIEW Basics and Intermediates on behalf of NI Australia. I always have to fill the SPACE/GAP with
all sort of different stories, Introduction to the topic, asking people questions etc... either it is LabVIEW starting up/restart or Signal express.
Havent got any chance for coffee during these kind of sitiuation.
-
QUOTE (Norm Kirchner @ Nov 19 2008, 03:12 PM)
http://wiki.lavag.org/LabVIEW_configuration_file/Miscellaneous#defaultConPane' rel='nofollow' target="_blank">See this WIKI entry.I belive this is what you are looking for.
Alternatively you can figure out the number for the INI file by going to:
C:\Program Files\National Instruments\LabVIEW 8.5\vi.lib\_script\XML Scripting
Assuming that your LV is installed in this folder.
In this folder you can open the Strict Type Def control named: Connector Pane Types.ctl
In here you can select the pattern you want and it also shows you the magic number that you are going to
use for your labview ini file as mentioned in the previous post: defaultConPane=[number]
PS: Hope that you are not using the 4835 connector pane as your default :laugh: (28 terminals)
-
To CRELF:
Congrats, Let me know when you want some :beer: at UTS - good thing to sit down, have a beer at Uni and all the good memories flash back sometimes.
Keep up all the good works mate
-
QUOTE (Securitysuite @ Nov 18 2008, 11:33 PM)
It is possible to use multiple color planes to store a 16 bit monochrome image. When doing this,
the 8 bits of the green plane and 8 bits of the blue plane would be used. This would result in an
this method. In addition, the process of converting the image to 32 bits can be time consuming
(depending on image size), so the speed of acquisition and AVI frame writing would decrease.
1) Convert the image to an array of signed 16 bit integers (using IMAQ ImageToArray function)
2) Cast the array to unsigned 32 bits (To Unsigned Long Integer)
3) Convert the unsigned 32 bit array to an RGB(U32) image (IMAQ ArrayToColorImage).
Once the final RGB(U32) image is created, you can write the AVI frame. When
reading the AVI frames back in, you would need to use the inverse of
the above steps (IMAQ ColorImageToArray, To Signed Integer, and IMAQArrayToImage).
Hope this give you something to start with.
You can also look at: http://www.alliancevision.com/us/products/...i_lib_v2_us.htm
Good luck.
-
Give NI a call and an application engineer might help you out. If not, i believe whatevar you can do in Vision Assistant you can do it
in LabVIEW so might be a good thing to learn how to develop application in LabVIEW. I used to be a student and I did all the vision stuff in LabVIEW, not Vision Assistant. You will understand the problem much better when you work in the lower layer, it's a part of studying, isnt it?
Good luck.
-
sorry it's hard to understand what you want from the question. Might be it is easier to narrow the question down or break it down to something simple first then building up from there.
In your Vi posted, you need to look further into the extract tone function you are using, as the signal is a single tone sinusoidal so this function will return 1 value for frequency and 1 value for
phase. It means if you want to use XY graph you need to have 2 1D array of each of the freq data and the phase data, bundle them up and wire to your desire XY graph.
I wrote a simple Vi which shows you 2 charts, 1 is for freq diff, and 1 is for the phase diff between 2 described signals. Whenever you change the value of the freq control of the 2nd signal, a
2 new values calculated and graphed accordingly. If you want to graph this relationship (freq VS Phase), you will need to created 2 1D array of data as mentioned above. I leave that task for you
to learn and figure out yourself.
Hope this is the idea you are after.
-
Instead of semaphore I normally use FGV (Functional Global Variable) or OO methods; the fact that people like to use other method than semaphore is mainly because the structure of semaphore i think.
You have to use couple of vis in your program and all the wiring to connect those vis make things more crowded sometimes. I agree that this structure can be a redundancy in the next version of LV.
-
QUOTE (TobyD @ Nov 12 2008, 04:58 AM)
That's what I did too. I went through the online exam multiple times taking screenshots (failing on purpose so I could take it again) and came up with a pretty good list of questions that I could go through in detail and recreate the VIs in question. I think I had about 150 unique questions. I actually found the real exam to be quite similar to the practice exam questions.That's what i am doing too, i have provided NI with couple of fake emails already
Got so far around 90 unique questions. I will go through a bit more this week as TobyD has 150, that sounds like a target.
I dont have much problem with knowledge of LV Basics or Intermediate as I had been teaching them for a year around Australia.
However I just cant stand "poorly worded" questions as Crelf said.
Thanks for everyone inputs, this thread is so far so good for someone who are preparing for CLAD. :beer:
-
QUOTE (crelf @ Nov 11 2008, 04:24 AM)
Really? What faculty? I graduated from the Science\Physics faculty (it's not important when
) on the Broadway campus. Does the bar still have the cheapest beer in Sydney? My wife (Information Science faculty) started at the Kurringai campus and the moved to the Broadway campus for here final two years.note: OK - we've hijacked this thread so much, I just had to split it into it's own thread
I was in Engineering (Electrical sub majoring in Telecommunication Engineering) on Broadway campus. I would think the beer in here is still the cheapest and there are many activities, happy hour, pool comp, etc... to help us stay awake sometimes. I should give it a visit tomorrow nite with couple of mates then.
-
It's not a particularily well worded question, but the answer is D - all of the above are error cluster components.
mmm...Im confuse because it says EXCEPT in the question. Doesnt it mean we need to select the WRONG answer among the
given solutions? However there is no WRONG answer in the list, they are all sound correct to me.
Here is another one to discuss:
What is an advantage of using For Loops over While Loops when working with Arrays?
A A For Loop can tell LabVIEW ahead of time how many elements to allocate in an output Array
B While Loops force LabVIEW to change the size of an output Array after every iteration of the loop
C Both A and B
D None of the above
I would choose A as A is an advantage of the For Loops over While Loops as the question stated.
However B is showing a disadvantage of the WhileLoops over ForLoop, so would this counted as another For Loops advantage?
If that is the case then C is the correct answer.
But to answer the QUESTION, I still stick with A. :headbang: Should I need a :beer: to stay focus?
-
to start with:
1. Under which of the following settings would you not apply a gain to your signal?
A 10 V signal with 0-5 V ADC range
B 5 V signal with 0-10 V ADC range
C 10 V signal, with 0-10 V ADC range
D 1 V signal with 0-10 V ADC range
I think this question needs to be more specific. What does it mean by GAIN here? the gain can either be greater than 1 or less than 1.
for the A answer, I WOULD apply a gain > 0 and <= 0.5 in order to bring my signal into the ADC range.
for the B answer: there is no need to use gain here.
for the C answer: 10V is at the high limit of the range, I WOULD apply a gain a bit less than 1 so that the signal is easier to see.
for the D answer: 1V is within the range, i can either use gain or not here. I think NI wants the answer to be YES in here for the gain
in order to have a better view of the signal as 1V is abit small compare to the setting of the range.
The answer that NI afters would be B as there is no need to set the gain there, but alot of cases there is no need to have gain for D as well.
Should the question be: Under which of the following settings, it is unneccessary to apply a gain to your signal?
Do you have something to share?
-
It's been awhile since I finished my Analogue and Digital Control subject but I think i did heard about the I controller.
However I havent got a chance to do that at Uni/ work. I mainly use P, PI or PD. P is ofcourse the one that you starting with
and most of the case you will received responses from the system and have a better understanding of the system before using
any of the other actions like I or D depends on on desired criteria/ specs. I reckon PI are most used, since derivative action is very sensitive to measurement noise, and the absence of an integral value may prevent the system from reaching its target value due to the control action. (from wiki).
As Clelf said, it is not too hard to implement it in LV, just abit of work, and i think that would be fun to do as well as it is a part of ur project.
follow this pseudocode:previous_error = 0integral = 0 start: error = setpoint - actual_position integral = integral + error*dt derivative = (error - previous_error)/dt output = Kp*error + Ki*integral + Kd*derivative previous_error = error wait(dt)goto startGood luck mate
-
QUOTE (crelf @ Nov 10 2008, 02:32 PM)
OK - thread officially hijacked. I started drinking it at uni too (UTS) because no one else in my dorm would drink it, so it was safe in the common fridge Thankfully I've found similar brews here in the US: Shiner Bock when at NI-Week in Austin and Motorcity Brewing Works Nut Brown when at home in Detroit.The world is so small, I graduated from UTS 2 years ago. Cheers mate ! :beer:
-
QUOTE (jithesh @ Nov 4 2008, 03:17 PM)
@nedThanks for your quick response...
one quick question....I'm connecting this bar code scanner to my USB port of PC.So wheteher this keyboard emulation can read the data from USB....?
i cant see any reason why not.
As long as you set the string control to has its focus b4 you scan, you would be able to receive result without doing anything else in LV.
you dont need to build anything if it is just get data from the scanner.
-
QUOTE (jgcode @ Nov 3 2008, 03:32 PM)
Different from the Modbus IO server, there is a Modbus Library available here thru NI as well as info in this KB. I have used this for serial comms successfully in the past.Surprisingly there are many aussies in this site ! :beer:
and surprisingly the questionee is not comming back to his/her thread
-
QUOTE (Variant @ Nov 4 2008, 10:37 AM)
Can you please give me an Example of Regular expression that find out the Number For this "This is Red apple 345673.vi" ...I guess the out put will be 345673 right ?You have two ways to achieve this: Scan From String or Match Pattern, just look at the 'detail help' for these 2 functions, they are so powerful !!
Here is an example on how you can do this in both methods:
Have fun playing with String data type
Executable doesn't work
in Application Builder, Installers and code distribution
Posted
QUOTE (Eugen Graf @ Nov 24 2008, 09:13 PM)
can you have english next to each error msgbox? "Danker"