Scaled data output from AI Read floats to maximum after switching relay

Relay turns off motor. Sensor data read from MAX remains normal, same data read with AI READ jumps to negative value then floats to maximum value over >10 seconds. I am using LabVIEW 7.1 with an SCXI-1000. Re-running AI Config and AI Start resets the data to realistic levels (matching those read by MAX). Is there an error in using AI Read with LabVIEW 7.1?

Sounds like your AI input is unterminated. Unconnected input will cause input reading to drift/float. Check connections, contacts, wiring, relays, etc...
- tbob
Inventor of the WORM Global

Similar Messages

Reverse data output from Agilent 3458A

I'm taking 500 sub-samples of a 500mS ramp waveform from a function generator with the attached vi, and the data output is reversed in time. That is, the data as displayed on the waveform chart shows the TRAILING edge first - a time-mirror image of the actual waveform captured. I thought this had to do with LIFO/FIFO, so I forced FIFO, but it doesn't help. What must I do to get the proper time-sequence data from the DMM?
Can't seem to attach my vi , but it's identical to the Labview sample Agilent 3458 Acquire Multiple Measurement.vi, with the addition of a VISA Write MEM FIFO.

Ok, the data just comes out as an array. Well if you know that the data is backwards, just use Reverse 1D Array (as I already stated) to flip it back.
I remember working with that DMM before. I never found a way to get the data to come out like a FIFO. That's just the way the instrument works. Reverse the array and be done with it.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines

How to get the CSV,DATA output from RTF template

Hi Jorge
Thanks for your help.
as in the link you have given RTF template can have the output type CSV,DATA but in the preview i can see only html,powerpoint,pdf,html excel .
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Thnaks in Advance

It is because it has been preconfigured with such outputs.
To modify and add more output types simply go to:
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How to read scaled data in Matlab?

I'm using the board PCI-6115, Labview and Matlab.
I have some questions related to that scaling of data. I'm using as base of my program the example:'Cont Acq to File(binary)', present in Ni Help. I acquire the data as i16(unscaled) and then read it in Matlab using the low level I/O functions:
fin=fopen('data.bin','r','b')
data=fread(fin,[5000,4],'int16')
Everithing is ok, but the data is unscaled.How can I scale the data?
I tried to modify the program to write to the file scaled data, but when I read it in Matlab, using the same procedure, I only get a matrix with 0. Does anyone know what is the problem?
Thanks in advance

Hello
Wow, I didn't expect an answer for me so quick and from you.
Actually, I did follow every your writing. I'm a kind of new labview user (only 2 month),
so I don't know much about the labview, but I think you're great.
I also read the writing about the bug in Cont Acq&Graph Voltage-To File(Binary).vi. in other thread.
I don't know much about that, but I think you're right for that.
You're exactly right for my labview. I modified two vis from example, "Cont Acq&Graph Voltage-To
File(Binary).vi" and "Grah Acquired Binary Data.vi". Actually I only changed one part, save I16 and read I16.
I need a 5MHz sampling data and it's so big. That's why try to use Matlab.
I copied, pasted your matlab code and made LVReadBIN.m file.
When I run it with my data file, I got this error.
===============
>> LVReadBIN(1000);
??? Undefined function or variable 'then'.
Error in ==> C:\Th\LabView\NI_6115\10192006\LVReadBIN.m (GetHeader)
On line 103 ==> then
Error in ==> C:\Th\LabView\NI_6115\10192006\LVReadBIN.m
On line 23 ==> headerInfo = GetHeader(fileName,pathName,dataBytes);
>>
================
I'm not an expert for the Matlab, but I don't think the "then" is not right commend,
so I deleted and run again. And I got another error.
===============
>> clear
>> LVReadBIN(1000);
??? Error using ==> fread
Out of memory. Type HELP MEMORY for your options.
Error in ==> C:\Th\LabView\NI_6115\10192006\LVReadBIN.m (GetHeader)
On line 104 ==> userHeader=fread(fid,userHeaderLength,'uchar');
Error in ==> C:\Th\LabView\NI_6115\10192006\LVReadBIN.m
On line 23 ==> headerInfo = GetHeader(fileName,pathName,dataBytes);
>>
============
I attached 5MHz sampling data file. I have to change the name. It's not a txt file.
You just change the name (extension) from "test-5M.txt" to "test-5M.bin".
If you don't mind, could tell me what my problem is? Am I miss something or did wrong?
I really appreciate for that.
Thank you very much.
Have a great day.
Best regard.
Aggie.
Attachments:
test-5M.txt ‏977 KB

Reprints output from concurrent requests

Hi, I copied the above Concurrent Program to a custom one and added 'XML Report Publisher' in the list of incompatible programs, because my custom program (Custom Reprints output from concurrent requests) should run only after XML Report Publisher completes. But the custom program ends in 'Inactive' Phase and 'NO Manager' Status. We tried bouncing the CM, but no luck. Any help is highly appreciated.
P.S: When I add XML Report Publisher to the list of incompatible programs for the seeded program - Reprints output from concurrent requests, everything works fine.
Thanks, Naveen Gagadam.

Hi Hussein, we are on: Oracle Applications : 11.5.10.2, Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bi on LINUX.
I am submitting my Custom Reprints output from concurrent requests, XML Report Publisher from FND_REQUEST.SUBMIT_REQUEST. I cannot print the XML report without adding it to the list of incompatible programs because even though I submit the Custom Reprints output from concurrent requests after XML Report Publisher, it starts off before the XML Report Publisher completes and eventually it ends up in a warning. Please see below 1/2 of the log file (Will post the Other half immediately) from $FND_TOP/log. The name of the file is five_0908.mgr, 'five' being the name of the instance
Thanks, Naveen Gagadam.

Will I lose data converting from double-precision to single-precision float?

Before you say yes...
I am using a crio device in scan-mode interface. The values that the scan mode returns are in double-precision floating point. Apparently I am supposed to be able to choose between double-precision floating point ("calibrated") and fixed-point ("uncalibrated") data, but this functionality appears to be exclusive to the fpga interface and is not available with the scan engine. Both data types are 64-bits per value, so when it comes to size-on-disk, either way is basically the same anyways.
The system is continuously recording 13 channels of double-precision floating point at 200Hz. Using the binary file write method, I have measured this to be about 92 MB/hr to disk. (over 120mb/hr with tdms and a lot more for write to spreadsheet) Simply put, this 92 mb/hr rate is just too much data to disk on this system.
The modules I am recording from, the 9236, 9237, and 9215 c-series modules, have 24-bit ADCs or less. Does this mean I don't need 64 bits to represent the number and maintain the same accuracy?
Can I coerce/cast the double-precision floating point values I am receiving from the scan engine i/o variables to another, smaller data type like single-precision floating point and still maintain the same accuracy?
Message Edited by rex1030 on 08-27-2009 04:19 PM
[will work for kudos]
Solved!
Go to Solution.

For some reason the scan interface isnt letting me output the raw U32 values. I think it might have something to do with the fact that I am using both scan engine and fpga interfaces in the project, but I am not sure. Any ideas why this is happening?
This is a picture of me right mouse clicking on one of the modules to try to get it to put out raw U32 values like this knowledgebase article says I can.
I put in a service request.. (Reference#7256901) because to be honest I have to know for sure whats going on. I am not one of the engineers/scientists that designed the experiment so I cannot say whether it is ok to chop some of the end of the number off. I would rather simply be able to record all the data in a smaller amount of disk space then go tell them we have to compromise somewhere, whether on sample rate or precision.
[will work for kudos]

GUI locks up when trying to read output from server

I have a client built in MVC fashion and have two GUI views. One view is for output from the server and input from the keyboard. The other view is for changing connection settings and starting the conection. The problem is when I make the call to connect from the connection GUI it is able to connect and set up the streams but both GUIs lock up once I start trying to output the text received from the server. The strange thing is that when I call these methods just from the Model and not via the GUI and its actionListener the whole thing works. I think it may have something to do with the loop locking up the GUI but don't how to resolve this.
public void monitorServer()
try
char inputChar = (char)fromServer.read();
while (socket.isConnected()==true && inputChar >-1 )
inputChar = (char)fromServer.read();
if ( ( (inputChar >= '0') && (inputChar <= 'z') )
||(inputChar == '\n')||(inputChar == '\r')
||(inputChar == ' ') )
String tempString = (""+inputChar);
mv.addText(tempString);
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"Connection Error", JOptionPane.ERROR_MESSAGE);
mv.addText("\nMessage not read.\n");
The code above is the bot that screws it all up. mv is the other view that it is outputting the text to.
Please help! I'm gonna fail my degree. :)

you need to run your server connection part in another thread.

How do I create individual xml files from the parsed data output of a xml file?

I have written a program (DOM Parser) that parses data from a XMl File. I would like to create an individual file with the corresponding name for each set of data parsed from the xml document. If the parsed output is Single, Double, Triple, I would like to create an individual xml file (Single.xml, Double.xml, Triple.xml)with those corresponding names. How do I create the xml files and give each file the name of my parsed data output? Thanks in advance for your help.
import java.io.IOException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
public class MyDomParser {
public static void main(String[] args) {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
try {
DocumentBuilder builder = factory.newDocumentBuilder();
Document doc = builder.parse("ENtemplate.xml");
doc.normalize();
NodeList rootNodes = doc.getElementsByTagName("templates");
Node rootNode = rootNodes.item(0);
Element rootElement = (Element) rootNode;
NodeList templateList = rootElement.getElementsByTagName("template");
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Node theTemplate = templateList.item(i);
Element templateElement = (Element) theTemplate;
System.out.println("Template" + ": " +templateElement.getAttribute("name")+ ".xml");
} catch (ParserConfigurationException e) {
// TODO Auto-generated catch block
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// TODO Auto-generated catch block
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// TODO Auto-generated catch block
e.printStackTrace();

Ive posted the new code but now I'm getting a FileAlreadyExistException error. How do I handle this exception error correctly in my code?
import java.io.IOException;
import java.nio.file.FileAlreadyExistsException;
import java.nio.file.Files;
import java.nio.file.Paths;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
public class MyDomParser {
public static void main(String[] args) {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
try {
DocumentBuilder builder = factory.newDocumentBuilder();
Document doc = builder.parse("ENtemplate.xml");
doc.normalize();
NodeList rootNodes = doc.getElementsByTagName("templates");
Node rootNode = rootNodes.item(0);
Element rootElement = (Element) rootNode;
NodeList templateList = rootElement.getElementsByTagName("template");
for(int i=0; i < templateList.getLength(); i++) {
Node theTemplate = templateList.item(i);
Element templateElement = (Element) theTemplate;
System.out.println(templateElement.getAttribute("name")+ ".xml");
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Node theTemplate = templateList.item(i);
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How can i use an ao card (pci 6723) to output data and to trigger an ai o acquire the data coming from the ao card?card (pci 6254) t

Hello
I am trying to perform AO (pci 6723) and to trigger my AO card (pci
6254) to read the data coming from the AO card. I am using LV7,1,
win2000.
Is an RTSI cable necessary or I can connect the trigger signals externally ?
I am using the LV example " multi function - synch ai-ao.vi" but i can't for some reason configure the trigger lines.
thank you in advance for your time.
Yiannis

Hello Yiannis,
If I understand you correctly, you want to synchronize your analog input and analog output that are started by a trigger on the analog input board. If you don't want to use the RTSI lines, your best bet is to export the AI Sample Clock and then read it in to the AO board. There is an example on ni.com called DAQmx - Synchronized AIAO Shared Clock. It appears to be having techincal issues so I have attached the example below. To export ai/sampleclock, use DAQmx Export Signal.vi after Get Terminal Name with Device Prefix.vi. Export Sample Clock to PFI3 (There are only connections between the sample clock and PCI3/4/8/9). Connect PFI3 on your AI board to PFI0 on your AO board (with a wire). Then change the source for the AO Timing.vi to Devx/PFI0. If you want to do triggering, stick the DAQmx Trigger.vi between the Timing property node and the DAQmx Start.vi on the AI task. I have shown how to do this in the modified version below. Please take a look at it and let me know if you have any questions. If you still get an error please take a screenshot of it and post to the forum. Have a great day!
Sincerely,
Marni S.
Attachments:
Synchronized_AIAO_Shared_Clock[Modified].vi ‏140 KB

Send data from GPIB Read Function to XY Graph

hello
I'm really new to LabVIEW so this is probably an easy one, but I'm having a serious issue trying to figure this one out. how do I send data from GPIB Read Function to a graph, let's say XY Graph. my data consists of a string of numbers, separated by commas, alternating between X and Y values. for instance:
0, 0, 0.1, 0.2, 0.2, 0.4, 0.3, 0.9, 0.4, 1.6, 0.5, 2.5, 0.6, 3.6, 0.7, 4.9
which would graph a parabola. I tried to connect the output (data) of BPIB Read Function to XY Graph, but I get an error. do I have to do something else before I send that data to the XY Graph? thanks for any suggestions.
r.
Solved!
Go to Solution.

first of all, thanks a bunch for replying
I added "spreadsheet string to array function" and it looked OK (I didn't connect anything to 'array type' because I couldn't figure out what those blocks were - I'm really new to LabVIEW"
I couldn't find "decimate array" so I added "decimate 1D array," which is what my labVIEW listed (I have 8.6). I fed that directly into "express XY Graph," which lets me feed separate X and Y values (or so I assume). but, even though the input to "decimate 1D array" and output of "spreadsheet string to array function" say 'array' - the program is not happy. when I move my mouse over the 'x', the following is the message that I get:
"you have connected two arrays of different dimensions.
The dimension of is 2.
The dimension of is 1."
I'm not quite sure what that means. any suggestions what I can do with it?
Attachments:
Picture 1.png ‏11 KB

Reading the output from another program.

I haven't used Java in a good long while so I need someone to point me in the right direction. I have a C program that I call from a command line (windoze boxen) and it spits out some neat data. I can call it from inside a Java program, but how do I then read the output from the calling Java program? I'd just alter the C program, but I lost the source.

This article explains how to correctly execute another program from your
Java program, and read its output:
http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html

How to store data into database by reading sql statements from text file

how to write java program for storing data into database by reading sql statements from text file

Step 1: Create a property file to add various queries.
Step 2: Read the properties file using ResourceBundle
Step 3: Use the jdbc to execute the query read from the property file.
So in future if you need to change query no need do any modifications in java program. But depends on how you use the property file.

How to retrieve data from a read-only Excel file

Hi Developers,
I'm trying to retrieve data from a read-only Excel file. I used the same code that I used to retrieve data from a normal Excel file, but it can't work.
My code is as followed:
try
InputStream KpExcel = new FileInputStream("kp.xls");
HSSFWorkbook Kpwb = new HSSFWorkbook(KpExcel);
HSSFSheet Kpsheet = Kpwb.getSheetAt(0);
catch(Exception e)
e.printStackTrace();
System.out.println("Exception: "+e.getMessage());
The error I received is as followed:
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:494)
at org.apache.poi.hssf.record.RecordFactory.createRecord(RecordFactory.java:224)
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at org.apache.poi.hssf.usermodel.HSSFWorkbook.<init>(HSSFWorkbook.java:210)
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at photoproductionsystem.Display.create(Display.java:73)
at photoproductionsystem.Display.init(Display.java:44)
at photoproductionsystem.Display.main(Display.java:229)
Caused by: java.lang.ArrayIndexOutOfBoundsException
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at org.apache.poi.hssf.record.UnknownRecord.<init>(UnknownRecord.java:62)
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at org.apache.poi.hssf.record.ObjRecord.fillFields(ObjRecord.java:99)
at org.apache.poi.hssf.record.Record.fillFields(Record.java:90)
at org.apache.poi.hssf.record.Record.<init>(Record.java:55)
at org.apache.poi.hssf.record.ObjRecord.<init>(ObjRecord.java:61)
... 15 more
Can someone please help me with my problem? Thanks a lot in advance!

Madeline wrote:
how do I ask at Apache mailing list?I wonder why it seems to be a strange idea to some people to look at the software vendor's site for product support. :p
http://poi.apache.org/mailinglists.html

Reading the output from a object running in the local machine.

Reading the output from a object running in the local machine.
By using a signed applet i am lunching a small application that returns an image object, how to read that without storing it in the hard disk.
Which means i need to read the image object return by the local application using applet or jsp .
i am using tomacat and an html page with an applet with it to lunch the application.

You can write that image in a binary format using OutputStream for System.out and then read it in your applet.

Create a continuous data stream from C++, and read it in LabView

Hello all.
I'm working on a project which involves connecting to a motion tracker and reading position and orientation data from it in realtime. The code to get the data is in c++, so I decided that the best way to do this would be to create a c++ DLL file which contains all the necessary functions to first connect to the device and read the data from it, and use the Call Library Function node to feed this data into Labview.
I'm having trouble though, since ideally I would like a continuous stream of data from the c++ code into Labview, and I'm not sure how to achieve this. Putting the call library function node in a while loop seems like an obvious solution, but if I do it this way I would have to reconnect to the device every time I get the data, which is quite a bit too slow.
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I'm using Labview 2010, version 10.0.
Apologies if the question is poorly phrased, many thanks for your help.
Dave
Solved!
Go to Solution.

dr8086 wrote:
This method sounds like an excellent suggestion, but I do have a few questions where I dont think I've understood fully.
From what I understand the basic premise is to use one call library function node to access a DLL which creates an instance of the device object, and passes a pointer too it into labview. Then a seperate call library function node would pass this pointer to another DLL which could access the device object, update it and read the data. This part could be in a while loop and carry on reading the data until a stop command is given.
That's it. I'm including some skeleton code as an example. I'm also including the code because I don't know how much you have experience with multi threading, so I'm showing how you'd have to use critical sections to guard the interactions between threads so that they don't lead to issues.
// exported function to access the devices
extern "C" __declspec(dllexport) int __stdcall init(uintptr_t *ptrOut)
*ptrOut= (uintptr_t)new CDevice();
return 0;
extern "C" __declspec(dllexport) int __stdcall get_data(uintptr_t ptr, double vals[], int size)
return ((CDevice*)ptr)->get_data(vals, size);
extern "C" __declspec(dllexport) int __stdcall close(uintptr_t ptr, double last_vals[], int size)
int r= ((CDevice*)ptr)->close();
((CDevice*)ptr)->get_data(last_vals, size);
delete (CDevice*)ptr;
return r;
// h file
// Represents a device
class CDevice
public:
virtual ~CDevice();
int init();
int get_data(double vals[], int size);
int close();
// only called by new thread
int ThreadProc();
private:
CRITICAL_SECTION rBufferSafe; // Needed for thread saftey
vhtTrackerEmulator *tracker;
HANDLE hThread;
double buffer[500];
int buffer_used;
bool done; // this HAS to be protected by critical section since 2 threads access it. Use a get/set method with critical sections inside
//cpp file
DWORD WINAPI DeviceProc(LPVOID lpParam)
((CDevice*)lpParam)->ThreadProc(); // Call the function to do the work
return 0;
CDevice::~CDevice()
DeleteCriticalSection(&rBufferSafe);
int CDevice::init()
tracker = new vhtTrackerEmulator();
InitializeCriticalSection(&rBufferSafe);
buffer_used= 0;
done= false;
hThread = CreateThread(NULL, 0, DeviceProc, this, 0, NULL); // this thread will now be saving data to an internal buffer
return 0;
int CDevice::get_data(double vals[], int size)
EnterCriticalSection(&rBufferSafe);
if (vals) // provides a way to get the current used buffer size
memcpy(vals, buffer, min(size, buffer_used));
int len= min(size, buffer_used);
buffer_used= 0; // Whatever wasn't read is erased
} else // just return the buffer size
int len= buffer_used;
LeaveCriticalSection(&rBufferSafe);
return len;
int CDevice::close()
done= true;
WaitForSingleObject(hThread, INFINITE); // handle timeouts etc.
delete tracker;
tracker= NULL;
return 0;
int CDevice::ThreadProc()
while (!bdone)
tracker->update();
EnterCriticalSection(&rBufferSafe);
if (buffer_used<500)
buffer[buffer_used++]= tracker->getRawData(0);
LeaveCriticalSection(&rBufferSafe);
Sleep(100);
return 0;
dr8086 wrote:
My main concern is that the object may go out of memory or be deallocated, since it wouldnt be held in any namespace or anything.
Since you create the object with new, the object won't expire until either the dll is unloaded or the process (LabVIEW) closes. So the object will stay valid between dll calls provided LabVIEW didn't unload the dll (which it does if the VIs are closed). When that happens, I'm not exactly sure what happens to live objects (i.e. if you forgot to call close), I imagine the system reclaims the memory but the device might still be open.
What I do to make sure that everything gets closed when the dll unloads before I could call close and delete the object is to everytime I create a new object in the dll I add it to a list, when the dll unloads, if the object is still on the list I delete it.
dr8086 wrote:
I also have a more general programming question about the purpose of the buffer. Would the buffer basically be a big table of position values, which are stored until they can be read into the rest of the VI?
Yes, see the example code.
However, depending on the frequency with which you need to collect data from the device you might not need this buffer at all. I.e. if you collect a sample about every 100ms then you could remove all threading and buffer related functions and instead read the data from the read function itself like this:
double CDevice::get_data()
tracker->update();
return tracker->getRawData(0);
Because you'd only need a buffer and a seperate thread if you collect data at a high frequency and you cannot lose any data.
Matt

Scaled data output from AI Read floats to maximum after switching relay

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