Analog input downsampling

Hello,
I am running a stepper motor with a counter, CTR 0 out/PFI12, every rising edge the stepper motor will turn one step. I want to make an analog measurement every so many steps. So, every M cycles of the counter, make N measurements. I am having a very difficult time figuring out where to start and have tried a few approaches, but have not made any progress, any suggestions?

Hi dwmoreau,
take a measurement for each rising edge, which is very easy when you use PFI12 as trigger for your analog measurement (see DAQmx example VIs). Then decimate the measurement values later on (DecimateSignal)...
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome

Similar Messages

Analog inputs no longer working on Audigy 2 ZS Platinum Pro's external dr

I have an Audigy 2 ZS Platinum Pro. After two years of use without problems, the analog inputs on the external dri've have stopped working. I get no signal from them, not even noise. All 3 inputs are silent, Line in / Mic and Line 2 in the front, and Line 3 in the back. Otherwise the dri've appears to function normally - I get output from the headphone jack, and the volume control knob works. I have not tested digital inputs or outputs, as I currently have no digital devices to connect to them.
I had made no major changes to my computer - software or hardware - when the problems began. I recently added a new SATA hard dri've, but the Audigy dri've did work after that.
I've taken steps suggested in another thread on this forum and uninstalled all Creative software and drivers, used the latest driver package's uninstall program as well as Driver Cleaner, and finally manually deleted everything related to Creative and Audigy from the system registry (and rebooted quite a few times in between). I then installed the original drivers from the CD that came with the sound card (a setup that has worked before), but still the problem persists.
Any ideas on where to even begin looking for a solution? I find it hard to believe that it's a hardware problem, since three inputs suddenly went silent at the same time, and no other connections were affected. Yet I've done as clean a reinstall as possible, and that hasn't solved the problem.
My current computer configuration:
OS: Windows XP Pro (SP2 and all latest updates)
CPU: Athlon XP 500+
RAM: 2x 52 MB
Motherboard: Abit AN7 (integrated sound chip disabled)
Video card: Sapphire Radeon 9800 Pro
Network card: D-Link DFE-530TX
Hard dri've : Seagate ST320026A, 20 GB IDE
Hard dri've 2: Maxtor 6L080J4, 80 GB IDE
Hard dri've 3: Seagate ST330083, 300 GB SATA-II

I don't have a Platinum Pro or the dri've, but a general hardware troubleshooting step I would take would be to remove the soundcard and either move it to another slot or re-seat it. Also, I'd disconnnect and reconnect all cables to and from the card and the dri've. If I had another machine I could try the card or dri've in, I'd do that. If I could borrow another dri've or even another card, I'd test those too. (Swapping parts is often the simplest diagnostic.) Yeah, maybe it's not a hardware problem, but I'd take these steps just to rule out some possibilities.
Edit: And if you can remove or disconnect the SATA dri've and restore the system to the condition before you installed it, that's another good test.Message Edited by Katman on 2-8-2005 2:56 AM

Usb 6009 multiple analog inputs

I am currently attempting to sample two different analog inputs at different sampling rates using a USB 6009. I keep getting the 'resource reserved' error and am wondering if this is not possible using this DAQ. Questions:
1. Does creating two analog input channels on the device cause this error?
2. Is it possible to sample at different rates on channels created in the same task? (i am trying to 'slow down' the second analog input to display switch points to a customer)
3. Running multiple analog inputs using independent timing would be better achieved by switching to a higher end DAQ? If so which would you recommend?
I have attached my vi. Thank you in advance for your help.
I surf therefore I am....
Attachments:
demo_nolvl.vi ‏27 KB

The DAQ boards only have 1 timing clock for the analog inputs/outputs. So you can only have 1 sample rate on a given card. I would recommend just sampling at the highest of the desired rates in a single task.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines

How do I use the analog input (ADC) to drive a motion profile in MAX

We are trying to use an anolog input signal from a DAQ card to control the motion contol axis. For now, we want the motor speed to follow a sinusoidal voltage waveform, and later on, we will be using a more complex velocity profile.
In order to accomplish this task, we have searched the user forum, and found information suggesting to operate the servo motor in 'slave' mode under the 'gearing' option. Therefore, we have set the Gear Master to 'ADC Channel-1', Mode set to 'absolute', Gear ratio 1:1, and provided the sinusoidal voltage (+/- 5V, 3 Hz) to the AIN1 connector on the MID-7654 controller. When using the 1-D Interacitve 'single axis' control panel, the motor runs at constant speed in one direction only. It does not react to the sinusoidal speed profile request as we expected.
How do we 'turn on' the 'slave' mode in MAX? Please talk us through the necessary steps and settings? Thanks.
Staffan

Staffan,
you can configure and enablethe Gearing mode in MAX and it should be activated after saving the settings and initializing the board. In 1D-Interactive you can't use Gearing. For better flexibility I recommend not using MAX for configuring and enbling Gearing. You better should do this in your application.
In fact there is a perfect LabVIEW-example that ships with the NI-Motion driver (Master Analog Input - Slave Axis Gearing.vi)
I hope this helps,
Jochen Klier
National Instruments
Message Edited by Jochen on 10-02-2007 08:37 AM
Attachments:
gearing.jpg ‏162 KB

I am getting a -50101 error when trying to get analog input from a compact rio

I am just doing the initial setup of my compactRIO system and have been able to successfully add the cRio in Max and then into a new project. I created a very simple VI with analog input that I am trying to read into an indicator, following one of teh tutorials. The module I am reading the input from is a cRio-9201. The input is voltage. I have already added the module to teh project under the FPGA, which is under the RIO in the project tree. Any ideas what I may be missing would be greatly appreciated!
Thanks

The 9201 C Series module needs to be created under the FPGA Target
(cRIO-910x) in the LabVIEW Project. You can either discover the module
or create it by type. In case you haven't created the FPGA Target
(cRIO-910x) under the cRIO Controller (cRIO-900x), you must do that
first. You also have the option of discovering the cRIO-910x or to
create it by type. I suggest you do it through discovery, so you don't
need to manually configure the addresses.
As how to create the items, that's done through right-click on the
cRIO-900x and select New>>Targets and Devices.... It will pop up
a dialog in which you expand FPGA Target and it will discover the FPGA
Target. Similar steps are followed to create the 9201 module.
If you don't see the FPGA Target and C Series module options, then you
need to make sure NI-RIO 2.0 is installed in you computer.
JMota

How do I acquire multiple signals in the NI cDAQ 9172 using 2 analog input modules?

Hi everyone,
Is anyone familiar with using the NI cDAQ 9172? This is my first time using it and I am not sure what exactly I am doing wrong... Alone with a NI 9233 analog input module, it works great. I can grab my 4 signals from each channel and go. However, when I add another analog input module to the mix, it gets an error. It looks like it is reading only one and not the other. It bombs at one of the DAQ start task and read task.
Basically, the block diagram is just a double of the one 9233 working alone. Is there something needed for input to make the 9172 working? Any ideas?
Any help is much appreciated. Thanks!!

Hi Jud,
Both threads are correct. The cDAQ-9172 has a single analog input timing engine, so both of your analog input modules will need to be in a single task. The other VI you referenced shows one analog input task (with channels added from two modules) as well as an analog output task. Analog output has a separate timing engine from analog input, so both of those can run in parallel independent tasks.
The beginning of this thread is a good example; a single DAQmx Create Task followed by a DAQmx Create Virtual Channel for channels from each module. Also, Getting Started with NI-DAQmx will give you the fundamentals for data acquisition, though I don't know how many of their examples use CompactDAQ.
Regards,
Kyle

Synchronizing two counter frequency inputs with multiple analog inputs

Hello all,
I'm fairly new to LabVIEW and I'm trying to collect data from multiple sources with synchronized timing on the acquisition but I'm having trouble figuring it out. My problem is that I've got two counter frequency inputs, one optical tachometer reading one pulse per revolution, and a max machinery flow meter with a k factor of 12000. I can't seem to figure out how to sync the timing with my multiple analog inputs. I've been attempting to get the tachometer to sync with the analog inputs first by following the example linked here. (https://decibel.ni.com/content/docs/DOC-10785) So far each time I run it I either get a timeout error on the DAQmx read or a "Multiple sample clock pulses were detected" error (see attached image). It seems if I slow the sampling rate way down to say 10 hz and ensure that the tachometer signal is over 800-1000 RPM (13-17 Hz) before starting the VI then the program will run without errors until the RPM drops below that threshold then the "Multiple sample clock pulses" error occurs. The code is attached below.
Does anyone know of a more effective way of syncing counter frequency inputs with analog inputs? I'd like to have a VI that can show 0 RPM (and eventually 0 flow as well, but I think I need to figure out the timing of one counter before I add another as it seems I can't have two counters in the same task). Any help on this would be greatly appreciated.
LabVIEW version 13.0
cDAQ-9178 Chassis with NI 9401 for the two counter inputs and NI 9205 for the analog inputs.
Thanks!
Richard
Solved!
Go to Solution.
Attachments:
SimpleDAQ.vi ‏44 KB
LV_Error.JPG ‏31 KB

Maybe third times the charm?
So I've finally got a good handle on why the VI is having problems at low RPM though I'm somewhat embarassed how long it took me to do that
Because I have the counter time synced to my Analog input task if it doesn't see at least two pulses between the two clock pulses set by the analog input task I get the -201314 "Multiple sample clock pulses" error. This seems fine at first as it just sets a minimum RPM that I can measure and it's well below the area I'm interested in so no problems there. I tried a simple error handler that would clear the error when it happend assuming the loop would keep iterating until the RPM went above that minimum at which point I would get a signal again. This is not the case, the read function just continues to spit out the -201314 error even after the RPM is back in the readable range. So then I tried adding two case structures so that when the error occured it would stop the task, clear the error, and then start the task again on the next loop iteration (Code Attached). This also doesn't work as the error shows up again on the stop task and then AGAIN on the start task on the next loop iteration. It seems this error is not actually being cleared and once it happens it stays with the task regardless of what the error cluster is carrying.
Anyone have any ideas? The only solution I can think of is to just clear all tasks and recreate them each loop iteration until the RPM is readable again but that strikes me as a horribly clunky solution.
Richard
Attachments:
SimpleDAQ_1_Start Stop.vi ‏48 KB

Audigy 4 Pro Hub Analog inputs problem

&Analog inputs in Audigy 4 Pro external hub seem to be unsupported in Windows 7. Am I wrong?
I installed latest drivers, set mixer to monitor sound from line in, also tryed win ASIO, but I am unable to get any sound from Line in/Mic in.
Please help me clarify this issue, I?ve been trying to find an answer through different forums for hours! Thanks

Issue solved... line in /Mic is now working. Audigy 4 pro analog input is supported using latest windows 7 drivers.

Scanning of analog inputs in PXI 7831R FPGA

Hi all,
I am new to Labview FPGA Module. I am using Labview 7.1.1 and Labview FPGA Module 1.1 . I am using PXI 7831R FPGA Card.
I developed a program which is used to scan analog Inputs with given scan rate for given scan duration. I gave input as pulse signal with 1Sec period and 2 V amplitude.
If I scan one analog Input with 10ms scan rate for 1000ms scan duration I am getting correct values. But if I use 2 or more analong signals to scan at the same time then I am getting Multiple of periods. And also If I increase or decrease scan rate I am getting strange values. Could any body please check my code and help me.
Thanks in Advance.
Regards,
Sashi
Attachments:
AnlogIn_FPGA.zip ‏247 KB

customise your front panel with advanced picture creation metods
Attachments:
SUF.ctl ‏20 KB

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 use Digital output to turn on sensor for Analog Input?

I am trying to use a digital output to turn on an array of sensors that I then wish to read on 16 analog input lines. I have a 6024E DAQ card. I am planning to take data at 10-20 hz, so not terribly fast, but I will be acquiring for long periods of time (days) so I will be streaming data to disk.
I have a fair bit of experience in Labview basics, but can quickly get out of my depth when I try something new (like this). I have V6.01.
It looks as though the best way might be to do the DO and then a single AI as individual events, then write to disk and continue through the loop. I am puzzled, however, how to keep this cycle on schedule given that I don't know how long it will take to sample 16 channels
, write the data to disk and get back to the starting point... perhaps this is so fast that I don't need to worry about it? The actual timing of the samples (be it 10 or 20 hz) isn't too critical, as long as I can record at what time they were taken... it would be frustrating to find that I was several seconds off after days of data.

Hello,
Thank you for contacting National Instruments.
If you are worried about the time of your acquisition being off, then you should associate each voltage measurement with a timestamp. This will allow you to know the exact time at which the sample was taken and you will never be off. You can use the Get Date/Time in Seconds.vi in our while loop with your AI code so that you can read a sample and read the time. You can than log the voltage value and the timestamp to your file.
Regards,
Bill B
Applications Engineer
National Instruments

Application exe not displaying analog input measurements

i am using the compactDAQ cDAQ 9172, after building the exe all the other digital and analog output ports are working properly whereas the analog input section is displaying the value as Zero, if i read read this channel from the max, it reads the values without any errors.what might be the issues.

Hi Kodeeswar:
I have a couple suggestions first try to create your analog input application with no digital or analog output task just "analog input" and then build the executable and try it again; second if it is possible for you please try updating to the new drivers of (NI DAQmx), and third reinstalling the last version of the “labview run time engine”. Also the 9172 is the chassis so which module are you using to handle the Analog Input application? To synchronize multiple modules or chassis if this is your case these links might be able to help you so please take a look at: NI CompactDAQ Module Synchronization, Synchronized Continuous Analog Input Across. I hope I was able to help you.
Jaime Hoffiz
National Instruments
Product Expert
Digital Multimeters and LCR Meters

The device PCI 6036E: Analog Input error:"the device is not responding to the base address",Output :No signal

I am using PCI 6036E DAQ card, DAQ 6.9.2. , I have not connected to any external device.
When I tested card(in Test Panel of MAX2.2,DAQ 6.9.2) an error appearing �the device is not responding to the base address� � then I pressed Yes, Then TestPanel window appearing�
In analog Input Tag, there is an error �-10805�. This error also appearing when I run the standard analog input samples (use Delphi 6.0).
I tested analog output functions in TestPanel, Delphi Examples, LabView 6.1. There are not error appearing but there is not output signal (using Oscilloscope to see).
Output, Input digital functions are working correctly.
Next I try to foll
ow all the instruntions as recommended:
-Changing TO another slots PCI
-Reinstall Os WinXP,98SE�
-Use another Computer�
But all of the cases are still not working.(the above error still appeared, no output signal)

Nvd,
I'm sorry to hear about the problems that you are running into with your DAQCard. I can understand your frustration with the errors that you are seeing. You mention that you have tried to do some troubleshooting, I was wondering if you have tried all the troubleshooting techniques listed in this KnowledgeBase:
http://digital.ni.com/public.nsf/websearch/DCFCDB240788F8D486256D6A00834D80?OpenDocument
If you have tried all of those things, I would suggest one additional thing to try. I would suggest updating your NI-DAQ drivers to version 7.0. These drivers are the newest versions of our Data Acquisition Drivers, and can be downloaded from our website here:
http://digital.ni.com/softlib.nsf/webcategories/85256410006C055586256BBB002C128D?OpenDocument&
node=132060_US
If you have tried all of the above troubleshooting options, please post a detailed description of what you have tried. This may help to clarify what is going wrong.
Jed R.
Applications Engineer
National Instruments

Analog input downsampling

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