rkanders
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Posts posted by rkanders
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Asynchronous Message Communication (AMC) Reference Library
http://zone.ni.com/devzone/cda/epd/p/id/6091
LabVIEW Simple Messaging Reference Library (STM)
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Try re-installing your Python version. I had similar problem that went away after re-installing active state python.
Hi,
I have just started using LabView (8.2) and LabPython and I am having trouble importing modules. My code essentially looks like this:
import socket
class CLASS:
def __init__(self,attribute):
self.item = socket.socket()
When running the code in LabView (filename Test2.vi), via New Session -> Set Script -> Compile -> Execute Script, I get the following error message:
Error 1050 occurred at PYTHON Execute Script__ogtk.vi
->Test2.vi:<type 'exceptions.NameError'>,
global name 'socket' is not defined
The code works just fine outside of LabView. Is there some barrier I am unaware of, and is there a way to avoid/cirumvent it?
Thanks!
RColeman
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I don't think a classical database design with one single table for all sensors would be useful.
Rolf Kalbermatter
Why wouldn't a single table with say SensorID, TimeStamp, Data fields work? That approach actually scales a bit better because database does not have to be modified to add another sensor. On my PC that approach can insert about 900 records per second.
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^(?:\d+(?:\.\d*)?|\.\d+)(?:\d+)?$
this will also recognize .8
I am pretty happy that finally LV supports regexes, makes life much easier.
I use regex buddy to test expressions, here is the explanation it gave for the above regex:
Assert position at the beginning of a line (at beginning of the string or after a line break character) «^»
Match the regular expression below «(?:\d+(?:\.\d*)?|\.\d+)»
Match either the regular expression below (attempting the next alternative only if this one fails) «\d+(?:\.\d*)?»
Match a single digit 0..9 «\d+»
Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
Match the regular expression below «(?:\.\d*)?»
Between zero and one times, as many times as possible, giving back as needed (greedy) «?»
Match the character “.” literally «\.»
Match a single digit 0..9 «\d*»
Between zero and unlimited times, as many times as possible, giving back as needed (greedy) «*»
Or match regular expression number 2 below (the entire group fails if this one fails to match) «\.\d+»
Match the character “.” literally «\.»
Match a single digit 0..9 «\d+»
Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
Match the regular expression below «(?:\d+)?»
Between zero and one times, as many times as possible, giving back as needed (greedy) «?»
Match a single digit 0..9 «\d+»
Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
Assert position at the end of a line (at the end of the string or before a line break character) «$»
Created with RegexBuddy
Reinis
QUOTE (jpdrolet @ Oct 8 2008, 08:07 PM)
The expression ^[ ]*[+-]?[0-9]+\.?[0-9]*$ should match a floating point number^[ ]* : any number of spaces at the beginning
[+-]? : 0 or 1 sign
[0-9]+ : at least one digit
\.? : 0 or 1 decimal point
[0-9]*$ : any digit up to the end
It will not recognize a number beginning with a point like .8 but will reject the single . without any digit
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QUOTE (Michael_Aivaliotis @ Sep 18 2008, 05:48 PM)
You ain't seen nothing yet. Wait until you try to build an executable. I just got off the phone with customer support call which included remote assistance via copilot for about an hour. The customer was trying to figure out what these extra folders were in his build output. NI_Report, NI_HTML etc etc. Each folder was full of dozens of VI's. His quote: "I never saw these before in LabVIEW 8.5"Exactly! What a nightmare! :headbang: I just spent three hours on this trying to stuf everything into one executable. :thumbdown: Executable went from 2MB to about 10MB and it would not work on one PC with more or less similar setup. I think NI rushed this version of the toolkit without thinking through the implications. In my app all I was doing with the toolkit was open excel and put arrays in named ranges.
Does anyone have any good news about the new version of toolkit. Has anyone tried getting the old version working in LV 8.6?
Thanks,
Reinis
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QUOTE (george seifert @ Sep 17 2008, 09:31 AM)
That's what I meant. I believe it works for things other than Word, but I understand not wanting to use non-standard updates. I don't know of another good way to get around it. I agree that NI didn't handle this update right.George
Yeah, broke lot of my stuff. Report toolkit has always been annoying, especially when installing for different LV versions or different office versions.
Reinis
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I decided to put LV installation folder under version control. Mainly so that it is easier to keep in synch different development machines and to be able to do externals with Subversion. Subversion stores info in .svn folders which are hidden, nevertheless LV seems to see them.
I think it slows down some of the labview ops (menus, new... dialog, etc.). :clock:
Has anyone else had any issuses with this approach?
Thanks,
Reinis
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Hello!
I would like to keep using Tahoma font while developing on Vista on my laptop. My fonts are setup to be Tahoma 13pt for everything (sys,dlg,app), but whenever I paste some external to LV text, it pastes as my default OS font (15pt Segoe). I like Segoe for the OS, but do not like it in LV. Any suggestions on how to make pasted text be the same as my LV defaults? This mostly happens when I paste text from my editor or file browser into LV controls and has been annoying me for the a couple of months.
Thanks,
Reinis
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Well, the bug is in the deleted elements array. Only first element is returned.
Reinis
QUOTE (Jim Kring @ Apr 21 2008, 01:48 PM)
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I have had it happen as well, and fairly frequently. My solution has been source code control. If there is a problem I diff it and find offending VIs and then manually fix it or just revert.
Reinis
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I do like the auto tool, but still quite often end up using TAB to change tool selection. This often leads to pushing Cap Lock instead
. Caps Lock also is fairly useless so here are some tips on how to remap it.http://johnhaller.com/jh/useful_stuff/disable_caps_lock/
I remapped mine to Tab. Tab scancode is 0f, here is .reg file contents that do Caps to Tab remap. Reboot after adding this to the registry (log off/in might work as well)
Reinis
#put this in .reg file:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Keyboard Layout]
"Scancode Map"=hex:00,00,00,00,00,00,00,00,02,00,00,00,0f,00,3a,00,00,00,00,00
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I've noticed exact same thing in the last couple of weeks while making a template for the future projects. I have a main project library with bunch of sub-libraries, virtual folder with some libraries, and auto populating build directory.
Reinis
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I have pretty much stopped using automatic recovery feature. I just do more frequent saves and commits to my SVN repository.
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Same here. I did have fairly frequent crashes and LV recovered *.proj file.
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Some benchtop Fluke DMMs have trigger function that you can setup during connection. After trigger you can wait a bit and take an average or median of a couple of measurement points. This worked very well for me a while ago to measure voltages during incoming inspection. Other benchtop DMMs ptobably have the same function as well.
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I think it is fairly tricky and only needed if you are not a sole developer.
I keep my repository and even working copy on a removable mini usb drive (e.g. WD Passport). Usb Drive is fast enough for development, and it makes it easy to develop at work/laptop and at home, and LV does not complain about linking problems. I do make frequent backups of repository and have a duplicate working copies on network that get synched via script/button using SVN update command.
It would be interesting to know if anyone has a solution for your problem. I have thought about this before and could not come up with anything that could be implemented, especially if more than one developer are involved.
Reinis
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Great job with R/W anything VIs. Just recently I was running into a speed issue while using OpenG variant config VIs while loading a config style file with 300 or so lines.
Thanks :thumbup:
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I would go with MD5 hash and have the application use default values when file is corrupted.
I usually setup my INI file routines to have some means to validate and check for missing keys or at least sections and replace missing/corrupt items with default values stored in separate INI cluster. I use modded OpenG INI routines.
Reinis
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Tools->Advanced->Profile VIs
shows you how much time/memory is spent per VI
I personaly have never had much of an issue with serial ports, but I have never done anything that requires even ms response from serial port. IMHO serial port is more limited by coms speed then anything else.
Your problem is probably some sort of coms termination character issue, that would be only reason why labview spends time at the port. So make sure that when you read from the port that your timeouts and termination characters are setup properly.
RK
hey guys - thanks for the replies - what is this profiler? Will the help function explain it well? I do have delays on my loops - for the reason you stated - around the 150ms mark, just to stop labview thrashing away too much
this is such a hard assignment lol!Louis - i'm fairly sure what you said is the issue - labview is thrashing away at the port but it seems to take a computing age for things to get through
if you have any tips it'd be much appreciated cheers the assignment is using 2 PCs - bit daft - I have 2 so can do it at home, but most people won't and means they'll need access to uni over xmas instead of going home!
cheers guys
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Check if your loops are running at full speed. If you have multiple parallel loops running at full speed (or even one loop) it will starve the CPU. If that is the case, put a ms delay timer in you loops for say 50ms delay after each execution.
Also use profiler to find the slow parts of your code.
RK
Hi all,got a uni assignment on @ the moment - revolves around a car simulator running on 2 PCs, one is the controls, one is the 'car' itself
talking over serial port
I have got a bit of the way into it but think my underlying framework is wrong - as for the workings of the car itself I have a fairly good idea of what needs to be done.
It's the sync'ing of comms that's the issue really
as it stands i have one while loop housing each vi. within that, on the controls VI I have a while loop that continually collates the value of the controls (steering etc) and whacks them into a string. Another while loop sends this string to the serial port. Another loop reads from the serial port. Another loop is dealing with the returned data and processing.
on the car itself VI the same principles apply. One is reading from the serial port and extracting the data, one is writing stuff back to the serial port, one is dealing with the received controls
I suppose the problem lies in the syncing of sending and receiving
the delay from moving the steering wheel to the wheels (for now using a meter to represent) moving on the car is bad - takes about 2 seconds which seems wrong
anyone got any suggestions on the basic framework upon which to build - thinking about starting again, but reusing a lot of my functionality on a more sound framework
christmas is going to be fun!!!! any help would be very much appreciated thanks - this is causing serious stress right now!!! :thumbup:
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There is a free toolkit at this website. It lets you do some simple DB ops.
http://www.carancho.com/cgi-bin/view/Main/...WorkingProjects
I find NI DB toolkit to be pretty decent, but overpriced for what it does.
RK
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Send data to the test sequencer using notifier, then sequencer will always get fresh data.
You can use queue for GUI if you do not want to miss the data, or again use the same notifier as for test sequencer.
Notifiers in general are good in situations where multiple recipients need access to fresh data.
RK
I think you caught my point very well and thank you for your answer.As I told in my first post, I needed some data for test sequencer and this data needs to be available whenever I ask for it, immediately. And it also has to be the latest data. This data pops out of com port only every other second and is not available except the user needs this data also and so the UI merrily stores always the latest data.
I want to update the UI first and my reasoning was that it was almost
acceptable to ask this one data from UI. I still think it almost is but your argument is also too valid :headbang:. I'd rather do this the right way and let the UI do what it is supposed to do. As I'll be thinking 
of a better way to do this I'd still be more than happy to hear any suggestions as to where I should store this one value. I do want to steer clear of global variables. Should I just add one more thread (=loop) to handle this data?To the next point, Q preview, the preview no doubt is the correct way of approaching this, the reentrancy I (for some long forgotten reason
) tried to achieve only led me to problems. This went straight to top of my task list.And finally the (G)OOP is at the top of my study list. Currently I still lack some insight about it and can't really visualize the way I should build the architecture, but in due time I will. I do hope I'll be ready already at my next project.
LabVIEW Development System Has Stopped Working
in LabVIEW General
Posted
Try temporarily moving Labview.ini file somewhere else so that LV can re-generate it with defaults. That quite often has fixed for me this type of crash.
Reinis