GPIB and simultaneous analog input

i'd like to measure frequency with a HP53181A , which takes some gate time for good resolution, via a keithley GPIB card and simultaneously read 2 analog channels via a labPC card at maximum speed. i wrote stand alone vi's for both tasks which work well. I tried to combine them using two loops with one local boolean switch as startin condition. The analog input loop immediately measures at high speed (ca.100 Hz) but the GPIB loop only does one cycle after the analog loop stops. My email is [email protected] (icq 135297554)
please contact if you need additional information Thanks already

Bender,
I believe that your program is not running in multithreading mode. So it gives all resources to the most important operation, which is data acquisition, and then it performs operation such for GPIB instruments. There is a good knowledge base in the web addressing this issue, please check the KB "If I use multithreading, will my application run faster?" with special attention to the last paragraph. You can also get to that document if you browse through www.ni.com, select Support, and in the search box type: "+multithreading +labview +application +run +faster", this may bring you some good documents that will be of help. To check if y
ou have multithreading turn on please go to your menu Tools >> Options... >> Performance and Disk >> Run with multiple threads.
If you think you may need further assistance you can also get to us by navigating to www.ni.com/ask and view our contact information.
Good luck!
Nestor Sanchez
Applications Engineer
National Instruments
Nestor
National Instruments

Similar Messages

How to combine Digital Output, a delay and Analog Input in a fast loop

I need to develop a process loop that runs at least at 250 Hz that performs a Digital output, than a delay of 50 microseconds and than an analog input of all the channels. All will be done using ATI MIO 64E3 card. Of course, the acquired data will be processed, displayed and saved. The loop will be running for several minutes until user stops it.

The fastest and most precise timing will occur if you use hardware timing. You can apply hardware timing to analog input on the E Series boards, but not the digital lines. Let's focus on the analog input first. Continuous waveform scanning uses a scan clock, which can be the board's internal one or an external one which you apply. If you want to scan all the channels 50 microseconds after a digital rising edge, then you need an external signal to signify that scan clock.
The E Series boards also have 2 counter/timers onboard that you can use for this purpose. You can set up a retriggerable pulse generation operation, where the counter receives a trigger and then on the user specifications, produces a pulse. You can have that route to the analog input scan clock.
The trigger signal for the counter is that digital pulse. As I mentioned earlier, there is no hardware timing for the digital lines on an E Series board. We do have other digital boards (653x family) that have hardware timed operations if precision is important. If you are satisfied with software's resolution (in the milliseconds), then you can call the E Series board digital function in a loop with a software timer. That digital line can route to the counter to act as the trigger.
So, on the programming side, you can have three separate and independent operations in parallel. One is for the digital function to output on that line every so often. Another is for the counter set at the retriggerable pulse generation. The last is for the analog input. I will describe this in terms of LabVIEW, but it can be done in a similar fashion with the NI-DAQ function calls or Measurement Studio.
The digital examples are in the LabVIEW >> Examples >> Daq >> Digital >> E-Series directory. The Generate Retriggerable Pulse example is in the LabVIEW >> Examples >> Daq >> Counters >> DAQ-STC directory. The E Series boards use the DAQ-STC timing chip.
Go to the LabVIEW >> Examples >> Daq >> anlogin >> strmdisk.llb directory and start with the Cont Acq to Spreadsheet File. This shows how to continuously acquire data and stream it to disk while displaying the data on a chart. Streaming to disk is the efficient way to save data while you are acquiring, as it eliminates the overhead of always opening and closing the file through the iterations of the loop. This saves to a file that can be opened by other applications (Excel, Word, etc.), but it is not as fast as writing to a binary file, which must be opened and read back through LabVIEW. However, for your ~250 Hz rate, it should be fine. Then, go to the LabVIEW >> Examples >> Daq >> anlogin >> anlogin.llb and look at the Acquire N Scans -ExtScanClk example. This shows how to apply the scan clock. Here, the AI Start that you saw in the previous example is replaced by 4 VIs (3 AI Clock Config's and the AI Control). Make those changes to the first example and then add a constant 0 to the AI Control parameter for total scans to acquire. That specifies the continuous operation. The File >> VI Properties >> Documentation menu item of the example describes the physical connections.
If you aren't using LabVIEW, use the NI-DAQ User Manual and the NI-DAQ Help file installed on your machine. You can look at your AT E Series User Manual at the http://www.ni.com/manuals pages for more information on the hardware. Also, if you want to route those signals internally on the board, you can find some entries in the KnowledgeBase at the http://www.ni.com/support pages.
Regards,
Geneva L.
Applications Engineering
National Instruments
http://www.ni.com/ask

Labviewcode wanted to count pulses from analog input

Can somebody help me with the following problem?
I don't have a Data Aquisition board so I use my steppermotor controller, the MID-7604, and it's analog input to read from a
sensor (photointerrupter) which outputs 0 or +5 Volts. I want to count how many times an output of 5 Volts appears.
The problem is that the signal is not a Waveform, so the Daq functions in Labview won't work. I've tried to generate a waveform
from the signal but also no results.
What I have created now is a counter which counts every signal above an adjusted value. The problem is that it counts on and on
when the signal is above the value, I want it to count one time. (like a trigger which detect a low to high level signal)
In the attachment you see that program and an other I've found (event counter) doing what I want, but I haven't been able to transform it in to
my own problem. Please help me on this because I'm stuck right now.
Thanks in advance
Message Edited by Trabuca on 07-04-2005 02:56 AM
Attachments:
monitor ain pulses with display.vi ‏31 KB
Event_Counter.vi ‏39 KB

Hi,
there are some ways - one is using a shift-register.
Attached is a flank detector - each time "Boolean" changes from 0 to 1 or 1 to 0 the count is increased by one.
I hope that helps
Greez
Stefan
Message Edited by mycroft on 07-05-2005 06:41 AM
Message Edited by mycroft on 07-05-2005 06:41 AM
Attachments:
Change detector_LV.GIF ‏9 KB

Error -200279 with simultaneous analog input (different devices) and digital output.

Hi guys,
I am a beginner in Labview and have been dealing with this problem for a couple of weeks now and just can't seem to get it completely right, I have a feeling there are a few small bugs in my code/hardware setup.
I am running an scxi-1000 chassis with a 1600 module and 1302C along with a 1303 accesory for temperature measurements, this is connected to four thermoucouples. Unfortunately I have a limited number of modules available so I am also using a PCI-6221 DAQ card with an scb-68 breakout box used for a digital output and analog input voltage channel. Attached is my labview program. When I run the code at a 50 Hz sampling rate it runs with no errors but the data file comes out extremely wrong, this is also attached. When I run the code at 100 Hz I get error-200279 after a few loops. I used to have 2 daqmx timing VIs (one for each input), but the same error would eventually happen, I have also tried increasing the buffer size on said timing VI. I am also using an old computer (Pentium IV) could this effect the program?
I have learned a lot going through forms for similar problems to mine but I just can't get it to for an extended period of time, I have posted my simplest code.
Thanks in advance,
Luca
Attachments:
tc_2.txt ‏1102 KB
FinalCombined_2.vi ‏128 KB

Ok this makes sense. I have made the suggested modifications but still getting the same error with sampling rates of 100 Hz or higher. Could you check that I have implemented the queue VIs properly (new file attached)? Also when running at 50 Hz in debug mode it does not look like the second while loop (with the dequeue element) comes into play until I hit the stop button, once I hit the stop button I get the following error:
Error 1 occurred at Dequeue Element in FinalCombined_2.vi
Possible reason(s):
LabVIEW: An input parameter is invalid. For example if the input is a path, the path might contain a character not allowed by the OS such as ? or @.
=========================
NI-488: Command requires GPIB Controller to be Controller-In-Charge.
This leads me to believe I have programmed the queue elements incorrectly.
Thanks for your help, any suggestions are greatly appreciated.
Luca
Attachments:
FinalCombined_2.vi ‏102 KB

HT2998 Hi, I try to conect Mac Mini from 2009 with my HD Tv Samsung F 6400 . With Mini Dvi conection and adapter to HDMI input in TV I got picture but not sound! I have analog cable from the phones out from mac but imposible to conect to TV? Can you HLP

Hi, I try to conect Mac Mini from 2009 with my HD Tv Samsung F 6400 . With Mini Dvi conection and adapter to HDMI input in TV I got picture but not sound! I have analog cable from the phones out from mac but imposible to conect to TV? Can you HLP?

You really need a newer Mac Mini with a true HDMI output, because that Mac Mini's DVI output does not support Audio.
You might try a 3.5mm to RCA adapter
from the Mac Mini's headphone jack to the TV's audio input,
but that would require being able to select the Audio input in the TVs menu while using it's HDMI input.
Optionally you could also use an external 2.1 Speaker System or patch the audio from the Mac Mini to your home stereo system to enhance that older Mac Mini's audio.

How to input/output a digital signal and acquire an analog signal at the same time?

Dasylab, version: 8.0.04
Acquirement Card: PCI1002L
When I use DasyLab to acquire the analog signals is no problem without digital inputs and outputs,
and when I use DasyLab to input or output a digital signal is no problem also, but when I do that at the
same time, DasyLab tell me the rate is too high and stop.
so, I searched the manual book1 (user guide) for that, it showed me :
To internally equalize measurement time and system time in the analog input, digital input and counter
hardware modules, use the following settings:
   Synchronization: PC Clock
   Sampling rate: <= 5Hz
   Block size: =1
the problem is, if I set the Sampling rate to 5Hz, the speed of the acquirement datas is not enough for my
application.
so, how to improve it? who can give me a example programm for me. thanks!
by the way, I come from China, my English isn't good, I'm sorry.
Allen, China.

Hi,
Have things changed over the years?
I need to syncronise a digital output (Modul NI9474) and an analoge input (AI-Modul NI9203) module. I need to measure time intervals from a flank in signal A to a flank in signal B. I would like accuracies of the order of 1 ms. Currently, the signals are not synchronised, with errors of the order of 2 times the block length (block size x sample rate), sometimes much higher. The best I got so far was a block size of around 20 with a sample rate of 1 kHz.
If I use the master and slave settings on the RTSL settings, my program doesn't run properly.
If I use digital signals for input and output, I can syncronise them with RTSL settings and everything is good, but I can't always do that.
Also, if I do anything in the GUI (such as scrollowing something or going to another window), my output gets screwed up properly.
1. What can be done to synchronise AI with DO?
2. Is there something that can be done to avoid messing up the output when something happens in the user interface? (I know that I am messing up the outputs as they make some valves switch and that is loud).
Thanks in advance!

How to get signal from analog input and send it to analog output (real-time)

Hi everyone,
I am doing simple task in Visual C++ and I am using PCI-6221(37 pin).
Basically, I want to send same signal from 'analog input' to 'analog output'
at the same time (almost), to make it real-time application.
Can someone please provide me sample program.
I would appreciate if you could provide me with the good tutorial which explains
step by step everything about programing NI-DAQmx for C/C++.
Best Regards,
Khassan
Solved!
Go to Solution.

This is my code in C++, you can optimize it if it looks too messy. This code reads signal from analog input and outputs it through analog output.
To make this code work additional include directories and library directories must be added from NI.
I hope it helps someone.
#include <stdio.h>
#include <conio.h>
#include "NIDAQmx.h"
#include <math.h>
#define DAQmxErrChk(functionCall) { if( DAQmxFailed(error=(functionCall)) ) { goto Error; } }
int main(int argc, char *argv[])
int32 error=0;
TaskHandle taskHandleRead=0,taskHandleWrite=0;
int32 read=0;
float64 dataRead[1000];
char errBuffRead[2048]={'\0'};
char errBuffWrite[2048]={'\0'};
bool32 done=0;
int32 written;
DAQmxErrChk (DAQmxCreateTask("",&taskHandleRead));
DAQmxErrChk (DAQmxCreateAIVoltageChan(taskHandleRead,"Dev1/ai0","",DAQmx_Val_Cfg_Default,-10.0,10.0,DAQmx_Val_Volts,NULL));
DAQmxErrChk (DAQmxCfgSampClkTiming(taskHandleRead,"",100.0,DAQmx_Val_Rising,DAQmx_Val_ContSamps,0));
DAQmxErrChk (DAQmxCreateTask("",&taskHandleWrite));
DAQmxErrChk (DAQmxCreateAOVoltageChan(taskHandleWrite,"Dev1/ao0","",-10.0,10.0,DAQmx_Val_Volts,NULL));
DAQmxErrChk (DAQmxCfgSampClkTiming(taskHandleWrite,"ai/SampleClock",100.0,DAQmx_Val_Rising,DAQmx_Val_ContSamps,1000));
DAQmxErrChk (DAQmxStartTask(taskHandleRead));
DAQmxErrChk (DAQmxStartTask(taskHandleWrite));
while( !done && !_kbhit() )
DAQmxErrChk (DAQmxReadAnalogF64(taskHandleRead,1,10,DAQmx_Val_GroupByScanNumber,dataRead,1000,&read,NULL));
DAQmxErrChk (DAQmxWriteAnalogF64(taskHandleWrite,read,0,10.0,DAQmx_Val_GroupByChannel,dataRead,&written,NULL));
_getch();
Error:
if( DAQmxFailed(error) )
DAQmxGetExtendedErrorInfo(errBuffRead,2048);
DAQmxGetExtendedErrorInfo(errBuffWrite,2048);
if( taskHandleRead!=0 )
DAQmxStopTask(taskHandleRead);
DAQmxClearTask(taskHandleRead);
if( taskHandleWrite!=0 )
DAQmxStopTask(taskHandleWrite);
DAQmxClearTask(taskHandleWrite);
if( DAQmxFailed(error) ){
printf("DAQmx Error: %s\n",errBuffRead);
printf("DAQmx Error: %s\n",errBuffWrite);
printf("End of program, press Enter key to quit\n");
getchar();
return 0;

Analog Input and Output in One Single VI

I need help in setting both analog input and output in one single VI. How do I assign channels to be either input or output? How do I simultaneously uses both in one single VI with a while loop structure?? Which AO am I suppose to use to obtain signal from the function generator I have built to feed into the DAQCard-1200?? Help!!
Attachments:
Test1.vi ‏48 KB

One thing you'll need to be aware of is that you will need to DMA lines: one for AI and one for AO. If you don't, then you can configure the DAQCard to do without DMA using the Config VI. But you certainly can do this.
As far as your function generator, you will want to do a buffered analog output. You will write your buffer of points to the buffer, and then tell NI-DAQ how fast to update your analog output channel with these values.
So, you can be reading from AI and checking the AO process in the same while loop. Just make sure you handle the while loop execution (the wait it exits) correctly. This can get tricky when you're doing two types of measurements.
J.R. Allen

How to synchronize analog input and output from two different USB daq boards

Hi all,
I have two very differnt USB boards the NI USB 6008, which I am using to acquire the data (Analog Input) and a NI USB 9263, it is an Analog Output only board that I am using to deliver a signal (in this case a square pulse). The reason why I am not using the 6008 Analog Ouputs is because I need to deliver negative voltages and need the full +/-10V range.
Looking at similar posts I am pretty sure that I can't use an external trigger or a shared clock, I also tried to use the synchronization of timed structures but no cigar.
I am including a quick vi that I whipped out showing how the signal jitters due to the lack of synchronization. The AO from the 9263 connects to the AI in the 6008 in this example.
Solved!
Go to Solution.
Attachments:
Test Pulse.vi ‏117 KB

I talked to a specialist in the phone and tols me that it is not possible.

How to enable 2 or more analog input pin in arduino uno labview simultaneously for voltage analysis?

Hi everyone,
i am new to labview and using arduino uno board for measuring microwave analysis in my project. i want to measure the refflection coefficient by dividing two analog input received to arduino (Vref and Vin) to obtain so. problems come where i just can analyze only one analog input pin only. please, kindly helped to figure it out.i've try the others solution where i create two while loops for different analog pin. u can refer to my circuit in the attachment below.i really2 appreciate ur help, thank you.=)
Attachments:
reflection coefficient and Vswr.vi ‏665 KB
front panel.PNG ‏66 KB
block diagram.PNG ‏40 KB

Try this if you have a POT around hook it up to the arduino than use the AnalogInSerial.pde and load it to your arduino exit out of the arduino platform and than try my VI see if this helps you.
Harold Timmis
[email protected]
Orlando,Fl
*Kudos always welcome
Attachments:
TalkToArduino.vi ‏28 KB

Newbie, Would like to use analog input and graph

I was using the "Real Time Chart.vi" example in Labview 2011 and got it all set up using the random input it comes with. I have a USB-6008 that is set up and I can see the signal in MAX. The big question is how the heck do I get the vi to work with the analog input? If someone could modify the vi and add the AI0 as the input I would really appricate it!!
Thanks
Attachments:
Soil Moisture.vi ‏15 KB

trimixdiver1 wrote:
Aside from me adding the gage and bar graph, its the same as the example. Ive added the AI (purple) channel but I guess I need to add some Daqmx stuff to allow it to connect to the strip chart.
Wheres the analog in channel? Is this something you haven't posted yet? Make your changes, then post when you are ready.
Reese, (former CLAD, future CLD)
Some people call me the Space Cowboy!
Some call me the gangster of love.
Some people call me MoReese!
...I'm right here baby, right here, right here, right here at home

How to use both digital and analog input modules in the same worksheet - MCC USB1208LS

Dear all,
Hi, I am Imran. I am using MCC USB1208LS. I have created the worksheet using digital input module as below and able to execute (run).
But when i add another analog input module in the same worksheet and executes, An error Message pops-up as in the below image
I have connected temperature sensor sognal to the analog input of USB1208LS. When using analog input alone in the worksheet, it indiates the actual values.
is any black box solve? please guide me. I am attaching in images
We already placed a purchase order for USB1208FS. Will it sort out my issues?.
Thanking you,
Imran Mohamed.
Attachments:
present worksheet digital input only.JPG ‏67 KB
with analog input module.JPG ‏81 KB
error menu.JPG ‏77 KB

Hello Imran,
the USB-1208LS is not capable of running concurrent operations such as an analog input scan and ANY digital Ins, Outs, counter reads, or analog outs. In Dasylab, the 1208LS is scanning, and nothing else from that particular device can be requested of it while that is happening.
Yes, using the 1208FS will resolve some of these issues.
Please refer to the ULHELP.CHM file installed on your computer in c:\program files\measurement computing\daq for details on this issue, et al.
also I recommend you send your MCC/DASYLab requests for support to [email protected] as MCC staff (that includes me) does not normally monitor NI's Developer Zone.

2 analog input and 1 digital

hi,
i attach the vi..
in the following vi i have a problem with the analogs..
when i'm running the vi.. At the results.. olly one of the analog will show me the measuerements..
at the one time maybe the clock analog will give me the results..
and the other analog nothing.. and opposites..
why they don't work together? and and the 2 analog give measurements at the same time..
andrikos
Attachments:
2_analog_and_digital_inputs.vi ‏190 KB

Hello Andrikoscy,
For most multi-function DAQ boards what you're trying to do is not possible. If you want each analog input to run on a different sample clock then you'll need to look into a NI R Series Intelligent Data Acquisition Device. These DAQ boards have a built in FPGA and allow for more customization than M Series boards, including independent sample clocks.
To address your questions:
1. On a non-intelligent DAQ board all analog input channels must share the same sample clock--if you need two different rates I would suggest sampling both channels at the faster of the two frequencies and then just ignore some of the data points on the slower channel.
2. In order to find out the exact time between samples from an external trigger (instead of the constant dt inserted by the waveform acquisition), you will need to take a period or frequency measurement of your signal using a counter on your card. By taking a buffered period measurement you will get an array of the times between samples and with that you can graph your samples on a precise x-axis. Normal analog input tasks that use an external clock do not associate any exact timing information with when a trigger was received.
I hope this helps, and if you'd like more information on the R Series Intelligent Data Acquisition Devices please feel free to contact National Instruments directly at www.ni.com/contact.
Have a great day!
Brooks

Time measurement between counter output my device and analog input

Hello!
I'm trying to measure the time to generate a digital pulse train on the counter output, that goes to a frequency converter that controls a motor. So I think it'd be the best way to wire the output of the frequency converter with an analogue input and make a timestamp before I generate the pulse and a timestamp when I recognize the singal, but I think that wouldn't be a serious measurement ?
What's the best way to measure the time?
kind regards peter

hi there
well, there a several ways to do this. the problem with the software - timestamps is the minimal resolution of 1ms. i'd suggest:
- wire a copy of the digital pulse train to an analog input channel
- wire a copy of the frequency converter to another analog input channel
- create an analog input task with the two channels (the sampling rate defines the timing resolution,make sure to acquire enough samples to see the response signal)
- start this task
- send the digital pulse train
to optimize your acquisition you can use another copy of the digital pulse train as a start trigger for your analog acquisition.
-> then you'll see the digital pulse train on one of the analog channels and the frequency output on the other one. both channels have the same time axis with a resolution defined by your sampling rate (~us depending on your hardware). then you can analyze the data.
search the example finder for examples of how to create tasks and triggers.
Best regards
chris
CL(A)Dly bending G-Force with LabVIEW
famous last words: "oh my god, it is full of stars!"

Newbie: 6020E (USB) slow performance with mixed digital and analog input

Hi,
I'm using a 6020E to do analog and digital input, and I'm getting very bad performance.
Please note that doing IO in Labview is new to me!
I have read the post about 6020E slow performance, and it says I should do buffered IO.
Can anybody point me to some DOC or SAMPLE that actually shows or explains how one should do this. I need to read several digital IO lines (which I can combine in one port-read), and several analog inputs.
Seeing how slow the reading on the 6020E is, I am amazed there is only one post that deals with this issue.
I would be satisfied to get the 6020E into some sort of continuous read mode so that whenever I need data, I get the latest reading right away.
thanks,
Peter D'Hoye

Hi Peter,
Your cannot do buffered digital I/O with your daqpad. It doesn't have that capability. You can only make direct software calls with digital read/write from/to your port. So your digital IO is completely software clocked and not hardware clocked. The example you are trying is only for specific Simultanuous sampling boards or now also for M-series boards that are able to do correlated DIO.
Use the Cont Acq&Graph Voltage-Int Clk.vi example for your analog measurements. (NI Example Finder) For your digital IO you can only use the examples like Read Dig Chan.vi, Read Dig Port,...
There are indeed some slow performance issues with single point I/O Operations, that is correct.
Check the explaination below:
DAQPads are offered for the Universal Serial Bus (USB) and the IEEE 1394 (also known as FireWire). Both of these standards use a high-speed serial communication protocol between the computer and the device with a bandwidth up to 12 MB/s for USB and 400 MB/s for FireWire.
During a single point operation, the DAQ device requires a complete set of configuration commands. This is done through serial communication (USB or FireWire), making the process slower than in a PCI-based board. The speed obtained for single point operation in a DAQPad is system dependent; this means that your computer processor, memory, bus speed, and other factors alter the speed at which you can do single-point operations with a DAQPad.
For example, on the DAQPad-6020E, timed non-buffered analog input operations are limited to about 50 Hz. At higher rates, the software may become unresponsive. On a FireWire device, you can expect stable operation around 3,000 Hz. But again, these figures are system dependent.
Regards.
JV
NI

GPIB and simultaneo​us analog input

Similar Messages

Maybe you are looking for

GPIB and simultaneous analog input