Measuring time elapsed

I need to measure the time elapsed between a few commands in a program; is there any finer degree of precision than the millisecond?

R_Neufeld wrote:
Thanks, nanoseconds work wonderfully. I did consider simply taking the time in milliseconds over a few cycles and averaging it out, but it would be a little inaccurate considering at least on my computer changes under 4 ms to the clock do not register for some reason (eg I could run Thread,sleep(3) and the time in milliseconds wouldn't change)Check your accuracy assumptions: rerun your tests to see how timing data varies. If there is something I want to time I often loop and do it 100,000 or a million times and average the result.

Similar Messages

Measuring time elapsed for file output.

Hello everybody
I want to add a time constraint for a 'file output.vi'. I want to preset how long (time) should the vi write in my file. For eg. stop writing after 20 seconds. Please suggest an appropriate way for this. Am attaching my vi for your perusal.
Thanks in advance
Attachments:
pic 2.JPG ‏110 KB
TEST2.31.vi ‏419 KB

Firstly sorry to post on two threads. Next, i got hold of a colleague's zip drive here's is the code with your modifications. But this is not functional in the following manner:
1.The programme treats time to write in file and execution time of while loop alike, which is not required.
If i give 30s for execution of while loop and 20s for file write time. and start writing at the same time when i start the while loop it works file, even if i give 20s for both and start both fuctions at the same time it works fine.
But when i mention 30s for execution of while loop and 20s for file write time, and start the write function after 10s of while loop execution. I dont get data worth 20s which i want in the file.
SO please suggest proper modifications
Thanks in advance.
Vaib

Measure time elapsed in web server access logs

We are currently using iWS4.1. How do we go about configuring the webserver to log the timetaken for each request in the access logs (similar to microsoft's IIS using extended log format)

In article <[email protected]>, Bacrdi wrote:
> Hello and thanks for answering my question. I've made progress but what
> it looks like now is I'm unable to transmit streaming video to the
> internet from the server. I'm thinking I'll contact Craig Johnson
> consulting and work with him on this problem if he is available. I'll
> post an answer in case anyone else has this problem.
> Thank you,
>
Go ahead and give me a call. I'm back from my travels, and caught up
now.
In fact I just worked on a school in New Jersey where I had previously
set up filtering for 31 cameras to work over three different BMgr servers
at three different school locations. And the police use them.
(Funny thing - police explained the want to be able to check on problems
in case something happened like an attack that took out power to the
school, or some disaster, or even if they cut power in a hostage
situation. It was explained to them that a power outage would also cut
off their view of the cameras, to which they reacted with 'Huh! I guess
it would!')
Craig Johnson
Novell Support Connection SysOp
*** For a current patch list, tips, handy files and books on
BorderManager, go to http://www.craigjconsulting.com ***

How to measure time intervals

Hello!
I am sorry to bother this forum, but I haven't
found any faq for this group at faqs.org. Here is
my problem:
I have received a computer with LabView installed
and 2 DAQ cards (unfortunatelly, with no books).
I have built a program wich does few simple
tasks - it measures temerature from 4 different
channels at 100 measures/sec, plots it and writes
it to a file. I use 4 "AI aquire wavform"
instruments and not 1 multiple instrument. Now, I
would like to measure somehow the actual
intervals between the measures, if possible,
relative to the time that I press the start
button. I was not able to find how to do it, and
I would appreciate any help. Thank you
P.S. I would be very thankful if the cc of the
answer (if there
is one) will be sent to my e-
mail - I do not always have access to the
usegroups.
Sent via Deja.com http://www.deja.com/
Before you buy.

Ok.. try this code...
DATA : t1 TYPE i,
t2 TYPE i,
delta(16) TYPE p.
GET RUN TIME FIELD t1.
PERFORM get_data. "your block of code
GET RUN TIME FIELD t2.
delta = t2 - t1.
delta = delta / 1000000.
WRITE :/ 'Time elapsed : ', delta , 'Secs'. "time in secs.

Best way to measure time?

I have labview 7.0 and SC-2345 with several digital inputs. I have to measure time between digital input(rise or fall)and stop signal comes in my program with compare etc.
I have tried to measure time with 4 sequences and "get date/time in seconds" and i have also tried to use loop with shift register.
It seems not to work or accuracy is not enough. so how to do that?

I am very sorry If you feel I came across unfriendly in any way, my intentions were sincere and I wanted to help you improve your code by pointing out some common mistakes. Believe me, some of my early labVIEW diagrams from 10 years ago are much worse. In the meantime I have accumulated some experience with daily use, but am still learning every day.
By the way, I an not affiliated with National instruments. This is mostly a peer help forum where LabVIEW users from all over the world help each other improve their coding skills. (Only users with blue names are employed by NI!)
Certain things are not obvious looking at your code and once the desired functionality is clear we can help you to a more optimized version that actually works. Whatever you are feeding to the "elapsed time" indicator has nothing to do with elapsed time, but counts the iterations of the middle while loop. It is either 1 or 2, depending on the inputs. There has to be a more interesting output (see my next post!).
For example, let's just look at your inner while loop (see attached image). (1) The number of iterations is known when the loop starts, thus a FOR loop is more appropriate. (2) You are comparing a DBL with an integer using "equal". If by chance the operator would enter a fractional time (e.g. 1000.5), the comparison would never become true and this loop would go on forever. Your program will never finish! Not good!
An alternative, but safe code is shown below in the image. For integer times, it has exactly the same functionality.
Apparently, you want to measure elapsed time, and I am guessing elapsed time used by the code in your middle loop. I will attach a simplified example based on your program in the next message here.
LabVIEW Champion . Do more with less code and in less time .

How to Measure time taken for a some lines of code in a program?

Hi
I have one requirement to measure time taken for executing a block of code in report . How we can find it ?
Is there any way to code something in report to caluculate it ?
Please send solution as early as possible
thank u

Ok.. try this code...
DATA : t1 TYPE i,
t2 TYPE i,
delta(16) TYPE p.
GET RUN TIME FIELD t1.
PERFORM get_data. "your block of code
GET RUN TIME FIELD t2.
delta = t2 - t1.
delta = delta / 1000000.
WRITE :/ 'Time elapsed : ', delta , 'Secs'. "time in secs.

Measuring time between activation of two boolean

Hello
I want to measure the time elapsed between activation of two boolean variables/indicators. In my code I have DAQ acquiring 2 digital signals which trigger corresponding 2 boolean indicators. Now I am trying to measure time between the event when my first boolean indicator gets the signal and the event when my second boolean gets the signal. I am attaching my code. I checked DAQ and my indicators everything works fine, but just when I try running the code with the 'elapsed time' part, its not running. Any help will be appreciated.
Thank You.
Attachments:
Test Code.vi ‏45 KB

So, feel free to give more detail. I'll just give you a couple thoughts:
1) The primary issue with your code is that it probably doesn't do what you think it does. How this VI will run is that it will get one data from the DAQmx routine, then pretty much stay in the inner while loop since the event structure has an indefinite timeout. Worse, I don't think changing the value of the boolean controls would trigger the value changed event anyways. In the end, you don't even need the Event Structure to do what you want to do, nor do you need the inner while loop. Just check the values for each iteration of the outer while loop instead and do what you need to do with those.
2) You are acquiring only one data point at a time. Which is OK if your events are particularly slow with respect to the effective sampling rate of the of loop (which might be able to pick up signals that change on the order of milliseconds or perhaps a bit less). If your signals are faster, you need to think about reading lots of samples at a time (arrays of booleans) and properly triggering your acquisition close to the event it needs to pick.
3) If your signal is a pulse, make sure that the pulse width of the signal is much longer than than 1 / sampling rate. If it isn't, you could miss the pulse entirely doing this approach.
4) The faster signals (as long as your have a quick enough sampling rate), the best thing is always to use a counters approach. In many of the DAQ cards and peripherals that NI offers, there are counters that can be driven with the sample clock (one of the fastest clocks on the device) or even a faster time base, and then the 'events' can be used to trigger acquisitions of the counters. Meaning you get exactly what you want: data points that correspond to times when events occur.

Measure time until I get a signal?

Hello,
I'm quite new here, and I feel stupid about asking this question, but I have been trying now for a couple of days to make a VI that measure times until I get a signal in. I'm testing a timers accuracy, so when it turns on the power the VI should show me the time elapsed.
I'm just fighting with different kind of loops, but can't get any sense from it.
/gusse

Hi.
What kind of a signal is available? Since you post in 'counter/timers', let's assume it is some kind of 5V logical signal, which you can set to high als long as your timer runs.
Then, what you need is a simple tick count which is controlled by a gate. Use MAX to set-up a counting task. When choosing the counter, you will be shown which lines to hook up to. Measurment then is
'When Gate is high, count ticks till gate is low.'
Accuracy and time depends on the tick source. On a dedicated counter card such as 6602, 80 Mhz is available, hence 1/80 000 000 s is duration of one tick. Uncertainty in counting results mostly from the gate not knowing, when a tick comes by as it opens and shuts. So this gives a max error of 2 ticks. Other (probably main) source is signal quality, i.e. slew rate of your logical gate signal.
Does that help already? If not, please ask further.
Michael

Measure time in seconds everytime you run a VI

Dear Folks,
I am trying to measure speed of a wheel using a magnetic sensor and measure some other parameters in the vehicle. What I also need to document in my project is the amount of time elapsed (in seconds) everytime you run the program. Is there a way where you can measure the time elapsed in seconds in labview?
Any sort of suggestions or examples would be helpful.
Given below is an example of how I wanted my final output file to look.
Time(sec)    | Speed(mph) | Accleration |
0    23 5
1    24 6
2    25                 7
Thank you in advance!
--Rahul
Solved!
Go to Solution.

Hello,
Are you just trying to get the time that has elapsed on the computer itself? If so, there is a Elapsed Time Express VI here: http://zone.ni.com/reference/en-XX/help/371361F-01/lvexpress/elapsed_time/ . You can also measure elapsed time by using the Get Date Time VI and subtracting it from an initial sime as shown below:
-Zach
Certified LabVIEW Developer

Media encoder time remaining stops decreasing and processor drops to zero. Time elapsed keeps going up! File won't complete!

Please help anyone who can.
Firstly I know I have very little RAM on my system, only 4GB but I've been rendering the same kinds of files for weeks with no problems until the last few days.
They biggest issues is as follows:
My timeline in Premiere Pro CC 2014 has 1080p 50mbps MXF footage from a Sony PMW 200 and some similar footage replaced with an After Effects comp for green screen keying.
The clip, approx 2min, starts with a linked comp from after effects, then cuts to the mxf footage and back to a linked comp at the end.
I am exporting via media encoder to h264 1080p. The file rendered fine for about 40min with the processor at 50% approx. The processor then shot up to 99% for 10 mins and the render progress bar
went up to almost 90% complete.
Then the progress bar stopped, the processor dropped to 0%, time remaining is steadily climbing and so is time elapsed. I've tried pausing and un pausing the render que and nothing else is running in background.
I need these files rendered tonight!! I've tried this a few times and this problem keeps occurring sometimes with the remaining time shooting up to 74 hours!!
Can anybody tell me what I'm doing wrong?!
Windows 7 Professional (64 bit)
Dell Precision workstation 690
Intel xeon X5365 3ghz (x2)
4 GB RAM

Sounds exactly like what is happening to me. This is frustrating because it was a 30 hour encoding process and the place where it is stuck is right at the very end of the sequence on the 2nd pass, although there is still about 12% of the progress bar remaining. I guess that this is where it takes all its work and puts the separate files into the single video file. I really don't want to go through this again. The final video file is showing up though and is shown having the size that I am expecting it to be.
Any workarounds to somehow get this unstuck? I am hesitant to just try and open the file. I am going to try a couple of things and if I am successful at getting this to finish without restarting then I will be sure to post it here.
Also, I don't know if this has anything to do with this problem, but I looked at my system Activity Monitor, and there is a CPU process highlighted in red, it states:
Adobe QT32 Server (not responding)
Thirty minutes later...
I was incorrect above as to the actual problem. I paused the queue encoding that was stuck, then opened up the project again in Premiere Pro only to discover that there was an offline still image which I stupidly had renamed during the day. So I renamed the file back to its original name, reconnected the picture, saved the PP project. Then I started the encoding back up and still no luck.
So I paused the encoding again, went back into the PP project and rendered just the area under question, saved it, and exported it into the queue. Then just to be safe I went to the paused item in AME, and duplicated it adding another version into the queue.
Then I unpaused the encoding and ... SUCCESS!! Not sure which of the final steps did the trick, but I am guessing that it was the rendering of the part of the sequence that it was stuck on. Hope this helps someone.

*ERROR* Hangcheck timer elapsed

Hi,
I'm using intel sandybridge graphics (xf86-video-intel 2.15.0) with linux 2.6.38.4. Whenever I run app that requires OpenGL(e.g. glxgears), I GPU hangs about every 3 seconds.
dmesg shows:
[ 58.693676] [drm:i915_hangcheck_ring_idle] *ERROR* Hangcheck timer elapsed... blt ring idle [waiting on 6200, at 6200], missed IRQ?
I googled and didn't find anything useful. I thought is was a bug and should be fixed in the future until today when I tried Ubuntu 11.04.
When I boot to Ubuntu 11.04, glxgears ran perfectly, no GPU hangs no strange white striped or flicker (https://bugs.archlinux.org/task/23771)
I noticed that ubuntu is using kernel 2.6.38 and xf86-video-intel 2.14.0.
Anyone knows how come this can happen? or how to fix this?
Thanks

Falcata wrote:
I was about to post a new topic about this, but it seems I don't need to. I encountered this problem last night when I was converting my old server to a media system. This is what lspci says about my server's GPU:
00:02.0 VGA compatible controller: Intel Corporation 82845G/GL[Brookdale-G]/GE Chipset Integrated Graphics Device (rev 01)
Going to install kernel26-lts and see if that helps any
You can try this setup: https://bbs.archlinux.org/viewtopic.php … 58#p937758

Can't get from time elapsed/time left to volume control

On my iPod Classic 80 GB, "Now Playing" defaults to the "time elapsed/time left" view. When I try to get to "volume control," I stroke the clickwheel, but it often doesn't respond. I have the iPod in a Belkin rubbery protective skin that covers the clickwheel, but it seems responsive enough when I'm already at the control I want to use.
Is there a way to explicitly go from "time elapsed/time left" to "volume control" in a way that doesn't require the stroking action on the clickwheel? Alternatively is this a sign that the sensitivity of the clickwheel has somehow deteriorated? I've only had the classic for about 6 months and it shows no other signs of malfunction.
TIA!

You shouldn't be deleting old Tima Machine backups. When TM runs out of space it automatically deletes the oldest backups to make rioom for the new
http://pondini.org/TM/12.html

Execution time, elapsed time of an sql query

Can you please tell me how to get the execution time, elapsed time of an sql query

user8680248 wrote:
I am running query in the database
I would like to know how long the query take the time to completeWhy? That answer can be totally meaningless as the VERY SAME query on the VERY SAME data on the VERY SAME database in the VERY SAME Oracle session can and will show DIFFERENT execution times.
So why do you want to know a specific query's execution time? What do you expect that to tell you?
If you mean that you want to know how long an existing query being executed is still going to take - that's usually quite difficult to determine. Oracle does provide a view on so-called long operations. However, only certain factors of a query's execution will trigger that this query is a long operation - and only for those specific queries will there be long operation stats that provide an estimated completion time.
If your slow and long running query does not show in long operation, then Oracle does not consider it a long operation - it fails to meet the specific criteria and factors required as a long operation. This is not a bug or an error. Simply that your query does not meet the basic requirements to be viewed as a long operation.
Oracle however provides the developer with the means to create long operations (using PL/SQL). You need to know and do the following:
a) need to know how many units of work to do (e.g. how many fetches/loop iterations/rows your code will process)
b) need to know how many units of work thus far done
c) use the DBMS_APPLICATION_INFO package to create a long operation and continually update the operation with the number of work units thus far done
It is pretty easy to implement this in PL/SQL processing code (assuming requirements a and b can be met) - and provide long operation stats and estimated completion time for the DBA/operators/users of the database, waiting on your process to complete.

Query Execution time - Elapsed time v Actual time taken

Hi All,
I have this scenario where I am querying a single table with the following results. It is a very heavy query in that there are multiple aggregate functions and multiple unions on it. Even if the query is written poorly (i doubt it is) why would the actual
time taken to execute the query be much more than the statistics provided through the following commands?
SET STATISTICS IO ON;
SET STATISTICS TIME ON;
Attached are the stats provided for the relevant query in question.
Table '123456789_TEMP_DATA'. Scan count 178, logical reads 582048, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'Worktable'. Scan count 0, logical reads 0, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
SQL Server Execution Times:
CPU time = 936 ms, elapsed time = 967 ms.
2014-01-06 17:36:41.383
Now, although the CPU Time/Elapsed time shows that it takes less than a second, it actually takes more than 15 seconds to fetch the results. (This is the actual time that you get on the bottom bar of the Query pane as well.)
What is the reason? Why is it that there is such a big discrepancy between the numbers? How can I improve this situation?
Thanks!

Yes. I am returning a huge number of rows to the client.
The query is simply against a single table.
Select
'First Record',AVG(COLUMN1),STDEV(COLUMN1
),COUNT(COLUMN1)
FROM [TABLE1] WHERE (SOME CONDITION)
UNION ALL
Select 'Second Record',AVG(COLUMN2),STDEV(COLUMN2),COUNT(COLUMN2) FROM [TABLE1]
WHERE (SOME OTHER CONDITION)
Imagine there are 178 records fetched in this manner with 178 UNIONs. The WHERE clause will always change for each SELECT statement.
Now, the question is not so much about the query itself, but why the execution time is actually 15 seconds whilst the SQL STATISTICS show it to be 936ms (<1 second)
Thanks!

Getting time elapsed in AS3

I have some asynchronous stuff going on in my Flash movie and
would like to determine how much time elapses between two events --
e.g., a button click and the response from a socket server.
I'm wondering how to go about this in AS3?

Thanks for your response!
I took your advice on using getTimer() and it's working
swell. However, I was kind of hoping for something that didn't
require my Flash movie to be running the whole time. I have learned
that you can create a new Date object and access its time property
and that will return a value in milliseconds. You can later create
a new Date object, access its time property, and compare the two:
var start:Date = new Date();
trace('start:' + start.time);
//calculate PI to a million digits or whatever
var end:Date = new Date();
trace('time elapsed:' + (end.time - start.time));
I haven't tested that, but I think it'll work.

Measuring time elapsed

Similar Messages

Maybe you are looking for