Maximum number of samples in a waveform

Does anyone know what the maximum number of samples there can be in a waveform for the pxi 6561?

Hi Timothy,
This depends on how much memory is on the 6561 card, for instance if you have the 2 MB memory option this will allow you to generate 2 MSamples and Acquire 2 MSamples. The size of the sample i.e. 8 bit, 10 bit etc. really doesn't matter as the memory quoted is per channel so 16 x 2 MB. Also note that there is separate memory for generation and acquisition so 16 x 2 MB x 2 = 64MB memory total.
Hope this helps,
Nick

Similar Messages

What is the maximum number of samples that can be acquired with a single trigger using PCI-6036E DAQ card?

1. My PCI-6036E card has a FIFO of 1024 bytes in AI. Maximum how many samples can be acquired with single trigger for digitizing a waveform?
2. PCI-6036E DAQ card has got a AO with 10ks/s update rate? Can I generate a pulsed output with the AO of this card? I need a pulse of, say, 5 V and 1 kHz frequency.

Giri,
1.The trigger is usually for enabling the acquisition. I mean, when it is logic zero, you acquire nothing; however, when it is logic one, you start acquiring your waveform,and you can acquire continuously without having to worry about how many samples, unless you want to set your program for doing so. You can acquire continuously by implementing buffer acquisition. Finally, the FIFO that is in the board will not affect the buffer acquisition.
2.Yes, you can do that! You can generate your 5V signal with that specific frequency, and you should not have any problems, because the freq fits in the update rate.
I hope this information is helpful.
L Aguila
Applications Engineer
National Instruments

Sampling frequency Fs and number of sample #s in a waveform

Hi there,
It is probably a stupid question but I am still going to ask it:
I do not completely understand why in the "Basic Function Generator.vi" there is a distinction between the number of samples #s and the sampling frequency Fs..?
What is the purpose to have more or less samples in the generated waveform then specified by the sampling frequency of the signal?
I hope this question make sense (or am I missing something obvious)?
thanks,
Best,
Renaud

rihns wrote:
I am sending those values to an AO (to a mechanical system that reproduce the sended waveform) and record the signal with an AI. My problem is that when I reduce the number of sample as explained in the previous message, I enhance the number of cycles i.e the time of the signal seen by the AO but it does not seem to apply to the AI... see attached image (Fs = 305000 #s=30500 AO is in white AI is in red)
Why does the #s only affect the time of AO and not the one of AI? (the number of cycle is the same though, only the time base is different)
I think we need to see some code in order to get the full picture of what you are doing. The number of samples of the AO should have nothing to do with the AI.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines

DAQmxWriteAnalogF64() - array & number of samples

I plan to use DAQmxWriteAnalogF64() to output AO to my device. This is part of the code that generate the AO:
// DAQmx Configure Code
DAQmxErrChk (DAQmxCreateTask ("",&taskHandle) );
DAQmxErrChk (DAQmxCreateAOVoltageChan (taskHandle,"Dev1/ao0","",-10.0,10.0,DAQmx_Val_Volts,NULL) );
DAQmxErrChk (DAQmxCfgSampClkTiming (taskHandle,"",1000.0,DAQmx_Val_Rising,DAQmx_Val_ContSamps,1000) );
DAQmxErrChk (DAQmxRegisterDoneEvent (taskHandle,0,DoneCallback,NULL) );
// DAQmx Write Code
DAQmxErrChk (DAQmxWriteAnalogF64 (taskHandle,1000,0,10.0,DAQmx_Val_GroupByChannel,data,NULL,NULL) );
// DAQmx Start Code
DAQmxErrChk (DAQmxStartTask(taskHandle));
Questions:
1. DAQmxCfgSampClkTiming() specifies a number of 1000 samples with a rate of 1000 samples/second. dataLayout is DAQmx_Val_ContSamps, which is generate samples until task is stopped. Does this mean that the input array that I pass into DAQmxWriteAnalogF64() must have a size of 1000? This is single channel.
2. Say if I use a total of 4 channels, each has 1000 samples, then my input array must have a size of 4000, while my sampling rate remains at 1000 samples/second, correct?

Hello hn_sofec,
In regards to your doubt:
No, the input array that you pass into DAQmxWriteAnalogF64() does not necesarily have to have the same value than the number of the sample rate. The number of samples is just the number of samples that compose the waveform that you want to generate. Then, the sample rate, will determine how fast will you transfer to the output buffer those samples. For example, for an array of 100 samples (lets say that those 100 samples represents a complete period of a sine wave), and configuring a sample rate of 1000 S/s, it would take 0.1 s to generate the first complete period of the sinewave (array of 100 samples). After1 second you would have generated 10 complete periods of the sinewave.
I suggest you to review more examples in order to understand better how the functions work. I share you one here:
"NI-DAQmx: Continuous Multi-Channel Analog Output Example in CVI"
http://www.ni.com/example/25867/en/
Hope this helps. Best regards!
Daniel C.

Configuring IQ / Number of Samples for USRP2920

Hello,
I've been trying to record HF-Signal using the USRP 2920. I got unexpected behavior for some configurations of IQ rate and Number of Samples.
When setting the IQ to 1M as example and Numbers of Samples to 60984, the recorded file remaind empty even after recording over a long period of time. It looks like for a given IQ there is an appropriate Number of sample applicable.
Do someone know the trade off to be made between bo parameters?
thanks for any suggestions
Solved!
Go to Solution.

Hi Bolivar,
There are a few considerations and facts in my knowledge:
The number of samples that you specify as input to the fetch VI is the number of samples that will be fetched by your host from the NI-USRP device per fetch call.
NI-USRP driver (at the host level) will try to acquire these configured number of samples within the timeout specified by you and if it is not able to fetch these from the device you would get a timeout error.
The maximum communication speed/data rate between the device and the host is governed by the communication medium used between the two.(in this case the ethernet connection 1Gbit per sec).
Once you call the initiate VI the NI-USRP device starts capturing data.
So when you configure the timeout, number of samples and the IQ rate of operation following pointers might help.
Is the amount of data that you want to fetch (number of samples * data width) fetchable within the timeout configured ?
Are you fetching out samples quickly enough so that the device buffers do not overflow due to a high IQ rate ?
That being said. let's say we fix IQ rate at 1M
Very small sample sizes will result in a lower actual data rate due to the overhead associated with every fetch call might even cause device buffer overflow.
Very large sample sizes might work if above considerations are made.
A good sample size for your application might be found by making a small benchmark and calculating the actual time taken by the fetch VI call to execute to get a fixed amount of data at various sample sizes and picking the best sample size for your application. I think multiples of 1024 might work better for sample size.
I am not sure if this solves your problem.
Thanks.

Number of sample required

Hi to all the expertise,
In my labview program 6i, I design a scan rate and number of scans to acquire. Now I want to read 100 samples, which mean on my graph, I want to see 100 samples of waveform. How should I configure it, so that I"m able to achieve this.
Kindly advise.
Thanks

Simple as it
If it is a finite acq, keep scan rate as 100 samples /sec and number of samples to read as 100 samples
does this answer your query ?
if not, get back with more details
regards
Dev

Maximum number of records for usage of "For all entries"

Hi,
Is there a limit on maximum number of records to be selected from the database using "For all entries" statement ?
Thanks in advance

There is a UNDOCUMENTED(??) behaviousr
FOR ALL ENTRIES does ahidden SELECT DISTINCT & drops duplicates.
http://web.mit.edu/fss/dev/abap_review_check_list.htm
3 pitfalls
"FOR ALL ENTRIES IN..." (outer join) are very fast but keep in the mind the special features and 3 pitfalls of using it.
(a) Duplicates are removed from the answer set as if you had specified "SELECT DISTINCT"... So unless you intend for duplicates to be deleted include the unique key of the detail line items in your select statement. In the data dictionary (SE11) the fields belonging to the unique key are marked with an "X" in the key column.
^^!!!!
(b) If the "one" table (the table that appears in the clause FOR ALL ENTRIES IN) is empty, all rows in the "many" table (the table that appears in the SELECT INTO clause ) are selected. Therefore make sure you check that the "one" table has rows before issuing a select with the "FOR ALL ENTRIES IN..." clause.
(c) If the 'one' table (the table that appears in the clause FOR ALL ENTRIES IN) is very large there is performance degradation Steven Buttiglieri created sample code to illustrate this.

Maximum number of inputs in "write data"

Which is the maximum number of input channels in "write data"? It seems that it is only 16 inputs. I have more than 16 parameters in my application. What do you suggest? I would like to have all the data gathered in one file.
Solved!
Go to Solution.

Use the Multiplex module to combine multiple channels into one. Typically, use the "by block" setting. The output will be a single wire with all of the channels multiplexed in the block. You can have a maximum of 16:1 multiplexed. Use multiple Multiplex modules. They do not have to be symmetric, but you do need to keep track of how many channels are muxed onto a single wire.
In the Write module, click on the Options button next to the file format (ASCII or DASYLab) - at the bottom of the dialog box, you configure it to match how you multiplexed - by block or by value (by sample). Then, on the right, configure how many channels are multiplexed onto each of the input channels.
Doing it this way tells DASYLab how to de-multiplex the data in the file. You will lose channels names. YOu can configure channel names for the multiplexed channels by using global strings. At the very bottom of the dialog box you can assign a global string for each channel. Tedious... but it can be done.
- cj
Measurement Computing (MCC) has free technical support. Visit www.mccdaq.com and click on the "Support" tab for all support options, including DASYLab.

Maximum number of Folder tabs??

Is there a maximum number of folder tabs you can have on a form? If I add 12 folders to a form (and open the form in B1), I am not able to click on any of the folder tabs past the 9th folder.
To see what I mean, open the ComplexForm sample project. In the "Adding Folder Items" section, change the number of loop iterations to 10 (or higher). Then try to click on that 10th form when you run the project.

I'm currently having the exact same problem with using more than 9 folders.
I've managed to create a new set of folders so that when clicked they now look as if they are selected however as they are not grouped with the other folders when clicked the selected folder from the other group of folders doesn't deselect. Another problem I've got is positioning the new folders so it looks as if they are in the same group as the others as currently I can place them in the correct left position however you can see where they overlap.
Thanks
Steve

Error:the number of sample must be 0 please help.

dear genius.
I searched the same error in this board but I can not understand how can i fix my problem.
I am just a beginner in LV so I need your help. I made AM modulation and demodulation vi .
when I first used "simulated signal" as message signal, noting happened.
but, I changed simulated signal as "acquire sound", and add a play waveform, after that, problem occured.
actually, I can not understand about sample number or sampler rate .
how can i fix my problem?
and do you know some website to exercise digital communication using usrp and labview for trying ?
please let me know your idea.
thanks a lot.
Solved!
Go to Solution.
Attachments:
error.vi ‏164 KB

kimjihwan123 wrote:
thanks kingt of ni
thanks again. but can you tell me the differecne between sample rate and sample per second? (I thoungt it was same)
First of all Knight of NI is my title. Crossrulz is my alias.
Secondly, Sample Rate is the same as Samples Per Second. But you want to make sure your sample rate and number of samples gathered are the same from both sources. I would also turn off the Actual Time (or whatever it is called) in the Simulate Signal so that it just gives you the sine wave instead of using time to generate it.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
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What is the effect of output signal with the same sampling frequency but different number of samples?

Hi,
I'm using PXI4461 for audio measurement and there is a question about analog output. I'm using the Basic Multitone vi for generating multitone signal. The sampling rate is 200k and my question is how to determine the number of samples. I used an audio analyzer to measure the distortion of the output signal with 200k and 1k points and there are no different except the update rate. What number of samples is suitable for 200k sampling rate?
Thanks,
Bill

The Sampling Rate determines the maximum frequency that you can see (the rate/2 according to Nyquist).
The number of samples divided by the rate determines how long you will sample. This sample time can only be determined by you. Do you need .1 seconds worth of data, or 1 second? But note that the MINIMUM frequency that you can detect is 1/(Sample Time) or the Sampling Rate/Number of Samples. So if your system has a minimum and maximum frequency specification use that as your guild.
[email protected]

Maximum number of contemporary users

Hi Everybody,
in my company we're planning for a new "Portal & Wireless" installation, and we need to know how many contemporary users can be served by the system. We have a three-tier architecture, with two different servers for the middle-tier (IBM x342, with 2 intel Pentium III 1400 MHz processors and 2GBs Ram memory)load-balanced by a Radware machine, and with the infrastructure (DB, SSO & OID) installed on a 4 Ultra Spark 400 MHz processors system (4GBs Ram). Does someone know any sort of algorithm to get the maximum number of contemporary user? Otherwise, which way can I estimate that value? Do you know any 'enlightening' document about this issue?
Thanx!

There is no easy answer to this question. You may find this document interesting.
How your hardware performs will vary widely based upon what you run on it.
Estimating anything can be a complex and error-prone process, that's why it's an 'estimation' not a 'calculation'.
Primarily there are three approaches to sizing a portal implementation, these can be identified as:
Algorithm or Calculation based
An algorithm or process that accepts inputs from the customer (e.g. user count, page count, hits, latency, doc size etc) and attempts to deliver a processing requirement is probably the most commonly accepted tool for delivering sizing estimations.
Unfortunately this approach is also the most inaccurate.
When considering a logical n-tier enterprise class portal implementation the number of variables involved in delivering a calculation that even approaches a realistic sizing response would require input values numbering in excess of one hundred, and calculations so complex and sensitive that providing an input value plus or minus 1% of the correct value would result in wildly inaccurate results.
The other approach to calculation based solutions would be to simplify the calculation to the point where it was simple to understand and simple to use. Unfortunately the sizing results delivered from this approach would also be wildly inaccurate.
Size-by-Example based
A size-by-example (SBE) approach requires a set of known samples that may be used as data-points along the thermometer of system size. The more examples available for SBE the more accurate the intended implementation will be. Asking a customer how many users they will have, what those usage patterns are likely to be and what type of content they intend to deploy on the portal are all questions that they should be able to answer. Asking them the likely cache-hit-ratio for a portlet is probably something they won't be able to answer unless you're asking the right people. Normally in a pre-sales situation the customer will not know the answers to questions like that. Those are the types of questions that would be required for the algorithm approach.
Oracle has the ability to deliver targeted SBE sizing solutions for our prospective portal customers through reference implementation documents that outline both our internal deployments and customer's external deployments.
By using these real world examples both customers and Oracle can be assured that the configurations being proposed have been implemented before and will provide the performance and functionality unique to the proposed implementation.
Proof of Concept based
A proof of concept (POC) or pilot based approach offers the most accurate sizing data of all three approaches.
A POC allows the customer to do the following :
Test their portal implementation design
Test their chosen hardware platform
Test their caching strategy
Simulate projected load
Validate design assumptions
Validate Oracle9iAS Portal
Provide iterative feedback for their implementation team
Adjust or validate the implementation decisions made prior to the POC
There is, however, two downsides to a POC based approach, namely time and money.
Running a POC requires the customer to have manpower, hardware and the time available to implement the solution, validate the solution, iterate changes and re-test and finally analyze the POC findings.
A POC is always the best and recommended approach for any sizing exercise, it will deliver results that are accurate for the unique implementation of the specific customer, and that are as close to deploying the real live solution as possible but without the capital outlay on hardware and project resources.
Hope this helps
Jason Pepper

Illustrator won't run: "unable to set maximum number of files to be opened"

I have an intel macbook pro (core duo with 2GB ram) and a copy of purchased adobe creative suite 2. Other applications in the suite like photoshop, acrobat, etc can run on my mac without any problem. But when I try to run illustrator, it just shows an error message "Unable to set maximum number of files to be opened" and quits. I also installed a trial version of illustrator cs3 and got the same problem. Can anyone help? Thanks.
CC

Hi, I realize this is an old thread but it was unanswered and the issue has come up again in a newer thread:
http://forums.adobe.com/message/2534652
If the original poster sees this, can you reply tin the new thread and let us know if you were ever to solve this problem?
Thanks!

How to find maximum number of users we can assign for Hyperion Planning.

HI,
How to find maximum number of users we can assign for Hyperion Planning.i.e., how to find license limit in hyperion planning 11.1.2.1.
In Essbase propreties, the system is showing maximum planning users could be 65535.
what would be the number for concurrent scenario?
Thanks
Giri
Edited by: Giriprasad on Jun 18, 2012 2:18 AM

The number of users would be based on your license agreement with Oracle, the system is not aware of your license agreement so it is up to you to stick to it.
Cheers
John
http://john-goodwin.blogspot.com/

How to set up the maximum number of messages on a queue programmatically

Hi,
I am using IMQ 3.5 to implement a message layer for one of my projects. I created a "Job Status Queue", which receives job status report from a java application every minute. But I just want to keep the most current status report instead of all the job running history. How can I restrict the maximum number of messages to 1 programmatically?
Any suggestion or help will be appreciated.
Xiaoyun Tang

You can't limit the destination size programmatically, but you can do it administratively and associate a behavior to occur when the limit is reached. In your case it sounds like you want a queue, 1 message deep, and to discard the oldest message when the queue is full. When you create the physical queue on the broker you can specify these attributes (you can also update them on an existing queue). For example:
imqcmd create dst -t q -n StatusQ -o maxNumMsgs=1 -o limitBehavior=REMOVE_OLDESTFor more information see Chapter 6 of the Message Queue Administration Guide. In particular the "Managing Destinations" section:
http://docs.sun.com/app/docs/coll/MessageQueue_35_SP1
Joe

Maximum number of samples in a waveform

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