MATLAB and LabVIEW Communication Optimal Performance

I have tried my own code, searched through forums and examples to try and figure out best method to communicate between LabVIEW and MATLAB. Most of the information I found was over a year old and I was wondering if there was a better current solution. My goal is to work in LabVIEW to collect the data, process in MATLAB and return the results to LabVIEW. I have encountered some difficulty in my search and before I delve even further in to one in particular, I was wondering if anybody had an optimal solution with this communication protocol or solutions to my errors encountered thus far.
I have looked at the following methods.
1)TCP/IP and a very good example found here: http://www.mathworks.com/matlabcentral/fileexchange/11802-matlab-tcp-ip-code-example
When I try to adjust even the example and communicate for my own purposes I get the following errors
Error 63 if MATLAB server not running
Error 66 occurs if the TCP/IP connection is closed by the peer. In this case, Windows notices that no data is returned within a reasonable time, and it closes the TCP/IP connection. When LabVIEW attempts to communicate after Windows closes the connection, error 66 is the result.
However, the example itself works perfectly and does not get these errors
2)Math Script Node, works but the post below states that MATLAB Node is faster.
"computing fft of a 1024x1024 matrix ten times (attached code). Result is that Matlab node version takes 0.5s versus 1.6s for Mathscript node version."
http://forums.ni.com/t5/LabVIEW/Why-are-mathscript-performances-much-below-matlab-s/m-p/2369760/high...
3) MATLAB Node, which states it uses ActiveX Technology seemingly works well, but loses time for data transfer.
4) Trying to use the ActiveX functions or if there is other Automation potential.
5)Other solutions that I have not found that might be better suited.
Thank you for any help or suggestions in advance.

Barp and Mikeporter,
Thank you for your assistance:
The reason I need to do the processing in matlab is as you mentioned the processing script is coming from another person who has already developed it in matlab. I almost have to treat it as a black box.
The TCP/IP method was interesting is that none of the errors show up when I run the example but if I try to modify it in a new VI I get the errors.
I have attached a simple program that just has a basic butterworth low pass filter I am trying to confirm if it works in the Matlab node. I have done other simple codes which work, and this one does not seem the implement the appropriate filter. The LabVIEW signal and LabVIEW filter seem to work at the default values (but not if I change sampling rate) for the Simulation of signal, Matlab signal and Matlab filter work, but the Labview signal processed in Matlab is not working...
Ideally it would be bandpass filtered (0.1-30) at sampling rate of 256 Hz and further processed from there, but I can't even seem to get low pass to work in the matlab to labview communication.
Any help would be greatly appreciated. Once I have that working I will have more of an idea of the constraints of the actual processing Matlab Code I will be using.
Thank you again.
-cj18
Attachments:
labview_matlab_filter.vi ‏70 KB

Similar Messages

Difference between the Matlab and LabVIEW Hann (Hanning) functions

Hi All,
I'm hoping someone out there can satisfy my curiosity. I have been porting over some code from Matlab to LabVIEW and came accross a difference in the two implementations of the Hann function. Essentially:
LabVIEW has array length = n
http://zone.ni.com/reference/en-XX/help/371361J-01/lvanls/hanning_window/
Matlab has array length -1 = N.
http://www.mathworks.co.uk/help/signal/ref/hann.html
(where n= N in the two implementations)
As I'm not very clued up on signal processing I was hoping someone could explain why there is a difference in implementation and why array length was chosen for the LabVIEW implementation. According to wolfram the parameter a is full width at half maximum:
http://mathworld.wolfram.com/HanningFunction.html
http://mathworld.wolfram.com/FullWidthatHalfMaximum.html
Is the difference just due to the interpretation of what this value should be?
I've attached a modified version of the window comparison example to illustrate the diference.
Thanks,
Attachments:
Window Comparison from example.vi ‏32 KB

^N wrote:
LabVIEW has array length = n
Matlab has array length -1 = N.
Could part o the confusion be due to the fact that LabVIEW arrays start with index zero and matlab arrays start with index one?
I'll look at your code later...
LabVIEW Champion . Do more with less code and in less time .

Has anyone used Ethernet Gateway and LabVIEW, communicating with Ethernet/IP protocol ?

I have a PLC system (Jokab Safety B20) together with Ethernet Gateway (also Jokab Safety type E1).
What I want to do is to communicate with this unit using LabVIEW Ethernet/IP.
Read a couple of data and write a couple.
Has anyone anything like this with LabVIEW and Ethernet/IP ?
I'm completely new to using PLC's, but I have made a minimum PLC application, but can't get communication to work with LabVIEW (+ Ethernet/IP).

i generally use an OPC server to talk to he PLC and then use Datasocket to talk to the OPC server tags.
if that gaetway thing is an OPC server then you maybe abel to do data socket R/W via it.
Otherwise the NI OPC server may support that widget and (at the rate I bill out) is a good deal in the eyes of most of my customers.
Ben
Ben Rayner
I am currently active on.. MainStream Preppers
Rayner's Ridge is under construction

Relations between Matlab structures and LabVIEW clusters

I have a DLL created with Mathworks COM Builder, used as an ActiveX component in LabVIEW. Thus, I am able to have my Matlab functions inside LabVIEW. However, I have a problem regarding the pass of parameters between Matlab and LabVIEW.
When the Matlab functions parameters are simple -DBL, DBL arrays, strings-, there is no problem. LabVIEW does the right translation. But I have not been able to pass a Matlab structure to LabVIEW, which counterpart I think it would have to be a cluster. To solve this situation I need to split the structure components and pass them separately.
Does anyone know how to do it without the workaround?
Thanks in advance and have a good day,
spj

Hello Tishu,
1)       Can we use nested for loop in Mathscript node?
1) Yes you can. Remember that loops should be avoided as much as possible in m-scrips. Most of the times you can use vectorization to represent same task.
2)       Which one of these is feasible: 1) Matlab script node
                                                          2) Mathscript node
2) What exactly is the "Feasable" question? Real time (see below) or nested loops (see above)
      3) Is there any other way to interface between matlab and LV for real time signal processing?
3) Real time is different depending the application. Some applications need ns or ps real time (RF appls) others need seconds delay. Real time means "determinism". That a task will execute in a know time with little jitter. Windows is not a real time OS therefore nothing in it will operate in real time. Can you tell us something about the signal your are processing (Audio, Image fps, Radar)?
     4) Suppose X is 1D array (DBL) in Labview. And Mathscript code is as below:
For i=1:inf, 4) Is this vector a valid one? inf = Inf which is different from 1/eps.
Y= X-1;
end
Here X is input and Y is output.
Such code does not produce output (Y variable) in real time processing.
Does it wait till the FOR LOOP ends? Is there any solution to such problem? 5) What is this suppose to produce?
Let me know,
yardov
Gerardo O.
RF Systems Engineering
National Instruments

Does the USRP SDR require LabVIEW Communications?

I've recently installed LabVIEW 2013 on my machine, along with a whole bunch of toolkits:
LabVIEW 2013 English
VI Package Manager
LabVIEW 2013 Control Design and Simulation Module
LabVIEW 2013 Datalogging and Supervisory Control Module
LabVIEW 2013 MathScript RT Module
NI LabVIEW 2013 LEGO(R) MINDSTORMS(R) NXT Module (English)
NI Vision Development Module 2013
LabVIEW 2013 FPGA Module (English)
Xilinx Compilation Tools 14.4
LabVIEW 2013 Real-Time Module (English)
LabVIEW 2013 Touch Panel Module
LabVIEW 2013 Robotics Module
NI SignalExpress 2013
LabVIEW 2013 Sound and Vibration Measurement Suite
LabVIEW 2013 Statechart Module
LabVIEW 2013 for myRIO Module
NI Real-Time Execution Trace Toolkit 2013
LabVIEW 2013 System Identification Toolkit
LabVIEW 2013 Digital Filter Design Toolkit
LabVIEW Modulation Toolkit 4.3.4
LabVIEW 2013 VI Analyzer Toolkit
LabVIEW 2013 Database Connectivity Toolkit
LabVIEW 2013 Report Generation Toolkit for Microsoft Office
LabVIEW Spectral Measurements Toolkit 2.6.4
LabVIEW 2013 Advanced Signal Processing Toolkit
LabVIEW 2013 PID and Fuzzy Logic Toolkit
LabVIEW 2013 Adaptive Filter Toolkit
LabVIEW 2013 DataFinder Toolkit
LabVIEW 2013 Desktop Execution Trace Toolkit
LabVIEW 2013 Multicore Analysis and Sparse Matrix Toolkit
LabVIEW 2013 Electrical Power Suite
LabVIEW 2013 GPU Analysis Toolkit
LabVIEW 2013 Biomedical Toolkit
LabVIEW 2013 NI SoftMotion Module
NI Motion Assistant 2013
NI Vision Builder for Automated Inspection 2012 SP1
NI DIAdem Professional 2012 SP1 (English)
LabWindows/CVI 2013 Development System
LabWindows/CVI 2013 Real-Time Module
LabWindows/CVI Spectral Measurements Toolkit 2.6.4
LabWindows/CVI Spectral Measurements Runtime 2.6.4
LabWindows/CVI SQL Toolkit 2.2
LabWindows/CVI Signal Processing Toolkit 7.0.2
LabWindows/CVI PID Control Toolkit 2.1
LabWindows/CVI Execution Profiler 1.0
Measurement Studio 2013 Enterprise Edition for Visual Studio 2012
NI General Security Patch Q2 2013
NI TestStand 2013
NI ELVISmx 4.5
NI DAQmx 9.7.5
Xilinx Compilation Tools 10.1 (Requires Additional Xilinx Compilation Tools DVD)
NI Device Drivers - February 2013
I wanted to follow this tutorial with the USRP 2932, which will arrive soon, but I later found out that I don't seem to have any of the LabVIEW Communications. Will not having those prevent me from using the USRP radio? If not, then are there any restrictions on what I can do with the radio without Communications?

Hi BreadLB,
The link to the tutorial that you posted is based on LabVIEW Communications System Design Suite, a new software environment designed to accelerate algorithm prototyping and over the air testing. It is a completely separate and independent environment from LabVIEW. See my post here for more details. You can also download a free 30 day evaluation copy here. Your hardware is supported with both LabVIEW and LabVIEW Communications.
The NI 2932 is a network based USRP, and it has a small onboard FPGA. Because of that, the FPGA on that specific product is not a LabVIEW FPGA target. The NI 294x/5x family has a large Kintex 7 FPGA and can be programmed using LabVIEW FPGA or LabVIEW Communications, like in the tutorial that you posted. The NI 2932 can be used with your host PC and LabVIEW for a wide variety of applications. Unfortunately the tutorial that you linked in your post requires the NI 294x/5x hardware and LabVIEW Communications. If you have questions about a specific application for your 2932, please post more details and we would be happy to help.

Xilinx SDAccel and NI LabVIEW Communications System Design Suite win a pair of EETimes/EDN ACE Ultimate Product Awards

Last night, EETimes and EDN presented a number of ACE Awards including twelve “Ultimate Product” awards. The Xilinx SDAccel Development Environment for C, C++, and OpenCL won the Ultimate Product Award in the Development Kits category.
EETimes/EDN 2015 ACE Awards
From the SDAccel entry form:
“The SDAccel development environment for OpenCL, C, and C++, enables up to 25X better performance/watt for data center application acceleration leveraging FPGAs and combines the industry’s first architecturally optimizing compiler supporting any combination of OpenCL, C, and C++ kernels, along with libraries, development boards, and the first complete CPU/GPU-like development and run-time experience for FPGAs. SDAccel streamlines the development and deployment of critical algorithms such as Deep Neural Networks used in machine learning.
SDAccel includes the industry’s first architecturally optimizing compiler that makes efficient use of on-chip FPGA resources along with a familiar software-development flow based on an Eclipse integrated design environment (IDE) for code development, profiling and debugging, providing a CPU/GPU-like work environment.
SDAccel leverages Xilinx’s dynamically reconfigurable technology to enable accelerator kernels optimized for different applications to be swapped in and out on the fly. The applications can have multiple kernels swapped in and out of the FPGA during run-time without disrupting the interface between the server CPU and the FPGA for nonstop application acceleration. This functionality is ideal for swapping applications during peak loading periods.”
(Note: For more information about the Xilinx SDAccel design environment, see “CPU/GPU-like software development environment for OpenCL, C, C++ delivers FPGA-based app acceleration with 25x better performance/W,” “and “Latest SDAccel release adds 4 new hardware dev platforms, 4 new libraries, 6 new design services firms.”)
Vinay Singh accepts an ACE Award for the SDAccel design environment from Max Maxfield
The LabVIEW Communications System Design Suite from National Instruments (NI) won the ACE Ultimate Product Award in the Software category. NI’s LabVIEW Communications System Design Suite combines software defined radio (SDR) hardware with a comprehensive, unified software design flow to help engineers prototype 5G systems. The package includes built-in application frameworks for WiFi and LTE that enable wireless developers to focus on creating specific components based on existing standards rather than designing new algorithms from scratch.
The LabView Communications System Design software is coupled with the company’s USRP software-defined radio development platform for 5G research, which is based on a Xilinx Kintex-7 All Programmable FPGA. Wireless engineers can use the NI USRP RIO and the NI LabVIEW Communications System Design software to rapidly prototype real-time wireless communications systems and test them under real-world conditions.
(Note: For more information about the NI LabVIEW Communications System Design Suite, see “LabVIEW Communications System Design Suite combines SDR hardware with a unified software design flow for 5G development.”)
Congratulations to all of the talented developers from both National Instruments and Xilinx who created these award-winning products.

Communication problem with FP-2000 and Labview 7.1

I am using the FP-2000, DO-403 and TC-120 modules with Labview 7.1, being run on a host computer via an ethernet connection. The setup has operated flawlessly for ~2 years; recently, I have noticed that while a VI is running on my PC, connection to the FP module ceases. There is no pop-up "connection error" in my VI, and the all the power and status LEDs on the FP modules are normal. I can still interact with the VI on the front panel while it is running, but nothing is passed to the FP module. I have tried communicating with MAX when this occurs and receive a "no connection" message. Is there a simple solution here, such as rebooting the FP module? Or is it time to invest in new hardware?
Justin

I am having a very similar problem with my cFP-1804 and Labview 7.0. I have no problem initiating communication over ethernet, and the vi will run perfectly for hours or even days. Inevitably, however, at some point there is no longer communication with the cFP-1804. Data is no longer being passed either to or from the cFP-1804, and MAX will show that the device is not connected. I also will not see any pop-up error message that says the connection has been lost, either from Windows or from Labview. The vi will just continue to run as if nothing has happened. Turning the power to the cFP-1804 off and then on will always resolve this problem. Since I am using the cFP-1804 primarily for data logging, however, this behavior is particularly problematic as the system will record nothing but zeroes until I discover that the communication has been severed and perform the manual power cycling.
I have been unable thus far to determine the cause of this problem. Any help would be greatly appreciated.
Thanks,
Derrick

I have a problem with simulation in Matlab 6.5 and LabVIEW for PID controllers

I have a problem with simulation in Matlab 6.5 and LabVIEW. I have some methods for granting PID controllers in MATLAB to go but not LabVIEW. International Teams degree to transfer two but when I go past the fourth degree no longer work. We changed the formula for calculating the parameters for grade four and gave me some good values for Matlab award but when I put on LabVIEW have not settled. formulas are available in PDF and are. Please help me and me someone if possible. Thanks
lim.4 generation parameters in MATLAB program and comparison methods are for second-degree transfer function.
Solved!
Go to Solution.
Attachments:
Pt net.zip ‏2183 KB

This is the VIs what i try to make,but is not work. This pdf. document was used to create last VIs PID. thenk you for your colaboration.
Attachments:
PID create by me.vi ‏312 KB
tut_3782.pdf ‏75 KB

I have a 27" iMac and want to play Windows games with optimal performance. what do I need to do?

I have a 27" iMac and want to play Windows games with optimal performance. What do I need to do?

Install windows with Bootcamp. http://www.apple.com/support/bootcamp/

Arduino due and Labview wirelss serial communication using Xbee

Hello.
I am controlling a mobile robot using the Arduino due and labview
PWM value caculated on the labview is sent to Arduino due and then Due controls the robot.
These communicate wirelessly by xbee.
Now, I'd like to increase the communication speed between Arduino due and Labview.
but, when i set the value of the "Wait(ms)" function to below 10ms in Labview, communication has unstability.
so please let me know how increase the communication speed.
thank you.
-experiment image-
https://www.youtube.com/watch?v=oZdMCdHlDhM
- Arduino source-
#include <string.h>
int PWM1 = 5;
int DIR1 = 4; //direc
int PWM2 = 6;
int DIR2 = 7; //dir
float readNumber = 0;
float In1, In2, pwm, newtime, A;
float newposition1 = 0;
float newposition2 = 0;
unsigned int Aold1 = 0;
unsigned int Bnew1 = 0;
unsigned int Aold2 = 0;
unsigned int Bnew2 = 0;
volatile long encoder1Pos = 0;
volatile long encoder2Pos = 0;
int encoder1PinA = 8;//Encoder A pin
int encoder1PinB = 9;//Encoder B pin
int encoder2PinA = 11;//Encoder A pin
int encoder2PinB = 12;//Encoder B pin
int Direction1, Direction2;
float pwm1_limit=255;
float pwm2_limit=255;
float count_old = 0;
float power1_old, power1_old2, power1_old3, power1_old4, power1_old5;
void setup() {
// put your setup code here, to run once:
pinMode(DIR1, OUTPUT);
pinMode(DIR2, OUTPUT);
Serial.begin(115200);
Serial.flush();
Serial2.begin(115200);
Serial2.flush();
pinMode(encoder1PinA, INPUT);
digitalWrite(encoder1PinA, HIGH); // turn on pullup resistor
pinMode(encoder1PinB, INPUT);
digitalWrite(encoder1PinB, HIGH); // turn on pullup resistor
pinMode(encoder2PinA, INPUT);
digitalWrite(encoder2PinA, HIGH); // turn on pullup resistor
pinMode(encoder2PinB, INPUT);
digitalWrite(encoder2PinB, HIGH); // turn on pullup resistor
attachInterrupt(encoder1PinA, d1EncoderA, CHANGE);
attachInterrupt(encoder1PinB, d1EncoderB, CHANGE);
attachInterrupt(encoder2PinA, d2EncoderA, CHANGE);
attachInterrupt(encoder2PinB, d2EncoderB, CHANGE);
void loop() {
if(Serial2.available()>0){
String first = Serial2.readStringUntil('!');//랩뷰에서 받는 2개의 값을 분리하기 위한 소스("!"앞까지 끊고, "@"앞까지 끊음 ex)123!456@을 받으면 123과 456으로 나눔)
String second = Serial2.readStringUntil('@');//http://stackoverflow.com/questions/29504679/splitting-a-comma-separated-string-through-serial-arduino
float x = first.toFloat();//위에서 분리된 문자를 float형으로 바꿔줌
float y = second.toFloat();
newposition1 = -encoder1Pos; //Encoder signal
newposition2 = encoder2Pos; //Encoder signal
count_old = 0;
float power1 = x;
float power2 = y;
if(power1 >= 0){
Direction1 = LOW;
else{
Direction1 = HIGH;
if(power2 >= 0){
Direction2 = HIGH;
else {
Direction2 = LOW;
power1 = abs(power1);
power2 = abs(power2);
if(power1 > pwm1_limit){
power1 = pwm1_limit;
if(power2 > pwm2_limit){
power2 = pwm2_limit;
digitalWrite(DIR1, Direction1); //HIGH = back, LOW = forward
digitalWrite(DIR2, Direction2); //HIGH = back, LOW = forward
analogWrite(PWM1, power1);//PWM Speed Control
analogWrite(PWM2, power2);//PWM Speed Control
String strValue = String(newposition1);//숫자를 문자형으로 변환
String Q = "!";
String strValue2 = String(newposition2);
String stringThree = strValue + Q + strValue2;//문자 합치기
Serial2.println(stringThree);//Send encoder pulse to Labview
else {//when Serial communication stop
float count = count_old+1;
if(count > 10000){
newposition1 = 0; //Encoder initialization
newposition2 = 0; //Encoder initialization
encoder1Pos = 0;
encoder2Pos = 0;
else{
newposition1 = newposition1; //Encoder signal
newposition2 = newposition2; //Encoder signal
count_old = count;
Serial.println(count);
//Encoder Read//////////////////////////////////////////////////////////
void d1EncoderA()
Bnew1^Aold1 ? encoder1Pos++ : encoder1Pos--;
Aold1 = digitalRead(encoder1PinA);
void d1EncoderB()
Bnew1 = digitalRead(encoder1PinB);
Bnew1^Aold1 ? encoder1Pos++ : encoder1Pos--;
void d2EncoderA()
Bnew2^Aold2 ? encoder2Pos++:encoder2Pos--;
Aold2=digitalRead(encoder2PinA);
void d2EncoderB()
Bnew2=digitalRead(encoder2PinB);
Bnew2^Aold2 ? encoder2Pos++:encoder2Pos--;
}

piZviZ wrote:
Only data rate working is 9600 between labview and launchpad(arm cortex m4).Where all data rates work between Arduino serial port monitor and launchpad(arm cortex m4).
Since the only thing that changed is the Launchpad, then that must be the issue. Are you sure this device can handle more than just the 9600 baud rate? Are you sure you are even setting the baud rate on this device?

Google Earth Plugin and LabVIEW: High CPU usage when adding placemarks

Hi,
I posted this question on stackoverflow earlier this week but feel it might be better suited to the LabVIEW community specifically so I'm reposting here:
I'm writing an application which uses the Google Earth Plugin to display events on the globe. Each event is a single point kml placemark with an icon which is a 3kb png file. Placemarks are uploaded to the plugin as they are received by the software. I am experiencing increasing CPU usage with the number of placemarks that are added.
I have tested displaying a new placemark every second and running until the software running the plugin completely froze (graph attached). The GEPlugin (green trace) stopped responding (i.e. the globe did not respond to the mouse) at around 1200 placemarks added and CPU usage was at ~30%. When the software itself (red trace) froze the plugin was using around 50% CPU and ~3700 placemarks had been added). After the freeze, no new placemarks were added which caused the software to respond (but not the plugin) so I could clear all the placemarks. After the placemarks were cleared from the globe, the CPU usage of the plugin returned to around 5% CPU.
So what I've seen is that GEPlugin CPU usage increases linearly with each kml placemark added. Is this the expected behaviour/ a normal limitation of the plugin? If not is there a more efficient way of adding many placemarks to the globe?
I am using GEPlugin version 7.1.1.1580 (API version 1.010) and LabVIEW 12.0f3
Please see the test results attached. Any input greatly appreciated!
Original stackoverflow post:
http://stackoverflow.com/questions/20994323/google-earth-plugin-with-labview-high-cpu-usage-when-add...
Attachments:
Performance Log 020114_095115.png ‏82 KB

Hello,
I have had a look at your graphs and understood what you are trying to do. To me it seems that as the image gets more complex it gets harde to render which wold likely cause increase in CPU usage resulting in the freeze. I would suggest you try running the program on anoher computer to check on the RAM front of things. If this is a limitation of the GE Plugin then unfortunately I can not do much to help, but if you think this is a problem coming from your LabVIEW code then you can post your code here and I can take a look.

Communicate large number of parameters and variables between Verstand and Labview Model

We have a dyno setup with a PXI-E chassis running Veristand 2014 and Inertia 2014. In order to enhance capabilities and timing of Veristand, I would like to use Labview models to perform tasks not possible by Veristand and Inertia. An example of this is to determine the maximum of a large number of thermocouples. Veristand has a compare funtion, but it compares only two values at a time. This makes for some lengthy and inflexible programming. Labview, on the other hand, has a function which aloows one to get the maximum of elements in an array in a single step. To use Labview I need to "send" the 50 or so thermocouples to the Labview model. In addition to the variables which need to be communicated between Veristand and Labview, I also need to present Labview with the threshold and confguration parameters. From the forums and user manuaIs understand that one has to use the connector pane in Labview and mapping in Veristand System Explorer to expose the inports and outports. The problem is that the Labview connector pane is limited to 27 I/O. How do I overcome that limitation?
BTW. I am fairly new to Labview and Versitand.
Thank you.
Richard
Solved!
Go to Solution.

@Jarrod:
Thank you for the help. I created a simple test model and now understand how I can use clusters for a large number of variables. Regarding the mapping process: Can one map a folder of user channels to a cluster (one-step mapping)? Alternatively, I understand one can import a mapping (text) file in System Explorer. Is this import partial or does it replace all the mapping? The reason I am asking is that, if it is partial, then I can have separate mapping files for different configurations and my final mapping can be a combination of imported mapping files.
@SteveK:
Thank you for the hint on using a Custom Device. I understand that the Custom Device will be much more powerful and can be more generic. The problem at this stage is that my limitations in programming in Labview is far gretater than Labview models' limitations in Veristand. I'll definitely consider the Custom Device route once I am more provicient with LabView. Hopefully I'll be able to re-use some of the VI's I created for the LabView models.
Thanks
Richard

OWA doesn't work on all servers! "Use the following link to open this mailbox with optimal performance:"

Hi All,
I am having a problem with OWA. I have 3 2007 exchange servers on 3 different sites on the same AD Forest. My emails work fine internally and externally with outlook. I have setup Outlook Anywhere on Server No1 with external email address:
https://mail.company.com/owa
Everybody can login fine.
I have setup OWA on the other 2 servers with the same address, but when a user from that site tries to login gets the following message:
"Use the following link to open this mailbox with optimal performance:"
So the can't see their emails!
Please help me out as I am trying to solve it for days now and I can't find out what is wrong!
Thank you All!
Akitan

Hi Akitan,
From your description, CAS server 1 is exposed to the Internet. Other two non-Internet-facing Active Directory sites rely on the Internet-facing Client Access server 1 to proxy all pertinent requests from external clients. If I have misunderstood your concern,
please let me know.
In your case, I recommend you ensure that Integrated Windows authentication for OWA virtual directory is enabled.
What's more, here is a helpful thread for your reference.
CAS Proxy between sites of OWA /Exchange Virtual directory
http://social.technet.microsoft.com/Forums/exchange/en-US/895a304f-8fb1-4909-8b48-480a7303afd4/cas-proxy-between-sites-of-owa-exchange-virtual-directory?forum=exchangesvrclientslegacy
Besides, if your issue is urgent, you can connect Microsoft Support. For your convenience:
https://support.microsoft.com/?ln=en-us&wa=wsignin1.0
Anyway, if you still want to solve your issue on the forum, I will continue to help you.
If you need further assistance, please feel free to let me know.
Best regards,
Amy
Amy Wang
TechNet Community Support

How to acquire data through multiple channels in parallel using PXI 6070 E, PXI 4071 and LabVIEW?

Hi,
I am using NI LabVIEW, NI PXI 4071, and NI PXI 6070E to measure current through a variable resistance. Now, I am using one channel from SCB-68, but I want to add another channel in parallel so that I can have two resistors instead of one that I cam measure current through them.
I have attached a Pdf file showing the setup for hardware in use and LabVIEW code also.
Can anyone look at these files and give me guide lines or ideas that can help me resolving this issue, please.
Thanks in advance.
Best Regards,
Shaheen.
Solved!
Go to Solution.
Attachments:
IV copy for HS.vi ‏55 KB
Layout of NI Cards.pdf ‏248 KB

Your 4071 can only do one measurement at a time. Your DAQ cannot measure resistance either nor has it got any analogue inputs.
However, you could use a multiplexer and multiplex your 4071 DMM. This wont give you simultaneous measurements but can acquire data one after the other, the speed is obviously dependent on the multiplexer you choose!
Hope this helps.
Beginner? Try LabVIEW Basics
Sharing bits of code? Try Snippets or LAVA Code Capture Tool
Have you tried Quick Drop?, Visit QD Community.

GPIB and RS232 communication problems

I've been having several "interesting" problems with GPIB and RS232 communications in LabVIEW VIs. Some I'll mention at the end for curiosity, but right now I'm facing a rather big problem. I'm essentially self-taught at doing LabVIEW (using 8.5.1 right now), but by now I've had a lot of experience as their either has not been any drivers or pre-made VIs for the instruments I've needed or I've not been able to get the available drivers to work and had to write my own anyway (such as with the HP 3458A), but nothing seems to be working right now. I'm not at work, but we typically find forum sites blocked anyway (I can't even download the NI drivers at work since they house them on a ftp server, go figures) so I can't give the VI itself (it wouldn't be easy to get approval even if I could) so the best I can do right now is in words describe everything I've tried. I will be happy to post follow-ups of specific details if I can if they would be helpful.
I've been working on a routine to read data from an MKS 670 Signal Conditioner/Display with a MKS 274 Multiplexer with 3 connected MKS 690A Baratrons. Previously I've worked on programs using other older displays and the analog outputs which were being read by a DAQ card, but for a new project it was decided to try and just read the data directly. I first worked with a unit with just an RS232 Serial Port which I managed to get to work, but had so much problems with garbage readings and having to add checks and re-reads that by the end no matter what delays I added between each reading and how simplified the command routine down to just 2 sequences and the read that it took at least 10 seconds to get 1 reading from each channel.
Figuring maybe it was a limitation of the serial communications for these instruments I tried to re-work it for a unit with a GPIB port with which I'm actually much more familiar. The problem is that I cannot get anything at all from the unit through GPIB. Everything even the bare-bones built-in GPIB CLR function times out with no response from the instrument no matter how long I set the timeout limit and it also freezes the entire GPIB bus as well. It isn't a waiting issue as it freezes on the very first command. The GPIB initialization function seems to work (I typically find this to be unnecessary), but the instrument itself doesn't even respond with a status code. I've also tried just the basic GPIB write functions with even just passing the <cr> and <lf> characters as well. In Measurement and Automation Explorer most of the time the instrument won't even appear when doing search for instruments and when it does it shows as not responding to the *IDN? command (yes I've messed with the EOI, EOS, etc settings and I've even changed the GPIB address even though when it gets this far it confirms that I have the correct address) and even tried manually doing the *IDN?, *RST, and *CLR commands even with <cr> and <lf> characters which the manual for these units clearly states are compatible commands and NI SPY and everything show no response at all. I've tried 2 different GPIB units, 3 different computers including several that are not online and haven't been updated for a while, and using older LabVIEW versions, extensive re-booting and resetting of computers and devices and still nothing. I'm using an NI GPIB-USB-HS GPIB to USB adaptor which I've used extensively on other systems and even re-connected to those systems and everything worked fine. When I hooked up equipment that I knew was working, it would either freeze the entire GPIB bus until well past whatever timeout setting I set at which point all the instruments would appear, but none responding to *IDN? queries or nothing would appear at all, or if I manually turned it off when frozen the other instruments would work and most even respond to the *IDN? queries. The same goes for both of the GPIB instruments of this type that I tried and again for different versions of LabVIEW, difference computers (all Windows XP though), and every GPIB configuration setting I can find to mess with in every combination.
Any thoughts or suggestions would be greatly appreciated. I've had all sorts of weird problems with equipment and LabVIEW (you've got to love undocumented design features) that have frustrated me before, but I've never had an instrument never respond at all especially a GPIB one. Getting garbage yes, no response at all, no.
The side side issues I'm just mentioning as they may be related, but I'm really interested in the above as I have working solutions for these:
One I've had is with a Hart Scientific (prior to being bought by Fluke) 1560 Black Stack that would continually stop responding to GPIB commands when on a continual read function taking readings just every 4 seconds with 250ms between each GPIB read or write command but for up to hours in total and the times it stops responding are random as far as I can tell. I even started sending the *RST command before and after every read or write command and still it freezes. The only thing is to manually turn it off and then back on or manually go through the menus and manually trigger the GPIB reset routine at which point it immediately starts responding. However, when I got sick of having to babysit it and just decided to try the RS232 serial port (as that is all it has without the extended communications module) it works fine no problem and I can even get readings slightly faster from it. Using a Hart Scientific 1529 Chub-e it could give me data on all 4 channels every second without problems. I just find it a bit odd.
When I couldn't get any of the HP 3458A driver packs to work to even give a single measurement reading and just made my own using basic GPIB read/write commands using the programming manual I still have a few interesting problems in randomly when reading off the full possible 256 bytes on the bus and clearing the bus I often find garbage partial readings on the bus every now and then. I've added a few routines to do some basic checks, but it is annoying. What is really weird is when just doing basic DC Voltage reads the "-" sign will randomly be dropped from some readings (started as about 1 out of every 5, down now to about 1 out of every 10). Fortunately I'm taking several readings and averaging and taking the standard deviation with limits on the deviations and basically added a routine to say if there is even 1 negative number take the absolute value of all then make all negative, but again I find it weird.
Thanks.
-Leif
Leif King
Metrology Engineer
Oak Ridge Metrology Center

Greetings Leif,
I understand you have completed extensive troubleshooting techniques to pin-point the problem with the GPIB communication. To begin, I want to ask you a few questions to help me understand your set-up and the issue at hand.
1) Is the NI GPIB-USB-HS cable the one which cannot communicate with your instrument?
2) When using the GPIB-USB-HS, does the GPIB interface show up in MAX?
3) If yes, does the instrument appear in MAX after scanning for instruments (from what I understand in your issue, it does so in an intermittent manner..)?
4) What driver version of VISA do you have installed in your computer?
5) Are you able to communicate to the same instrument using another GPIB cable?
Thank you for trying out some of these steps again, but we want to make sure we rule out other aspects in the systems which might be affecting the GPIB communication.
As for your other issues, please post seperate threads for each so we can help you accordingly. Thanks!
Sincerely,
Aldo
Aldo A
Applications Engineer
National Instruments

MATLAB and LabVIEW Communication Optimal Performance

Similar Messages

Maybe you are looking for