Tshark LabVIEW Communication Issue

Hello. I am trying to call "TSHARK" from the command line through LabVIEW. I can call it fine from the command line, and I can call other command line commands through labview (like 'cmd') but every time I try and call tshark I get an error. Anyone got any idea what I might be doing wrong?
Many thanks, Alec

Hi,
I just changed the file provided in the following link:
http://forums.ni.com/t5/LabVIEW/How-to-execute-a-DOS-commands-with-LabVIEW-on-a-Windows-PC/td-p/3204...
and it worked for me.

Similar Messages

Load error in LabVIEW communications

Hello Everyone,
I am using LabVIEW Communications System Design suite. I connected USRP 2953R using PCI interface to the laptop. 802.11 WLAN framework is being used for the project. I had to check channel estiomation using antennas and it was done. Today, I am stuck with a load error while opening the project. It is saying that the project includes following featrues thta are not supported in this version of LabVIEW-
LabVIEW FPGA SystemDesigner plugin
USRP SystemDesigner plugin
FlexRIO SystemDesigner plugin
LabVIEW FPGA
I attached a screenshot of it. Please have a look and help me in sorting this.
Best Regards,
Ramya

Hi Everyone,
This was a problem due to communications suite license. I contacted the sales department and they gave me an activation key to extend the license(as I am using the suite on a trial period). There was a loading error because LabVIEW communications software was loaded instead of Suite which is not suitable for the respective plugins. The issue is resolved when I used the activation key to reinitiate LabVIEW suite. And I thank everyone who tried to help me.
Best Regards,
Ramya

Ethernet Communications Issue

Hello list,
I have an ethernet communications issue.
We can communicate with our products using two communications modes, ethernet, and a proprietary CAN. For the ethernet connection, I have a router that assigns a DHCP address to the product (169.254.130.005). For the CAN connection there is a hardware ethernet to CAN adapter that has an assigned address of 169.254.130.006.
Below is a simplified example of the code I use to talk to the product. (there is only one loop...two loops are shown. One showing the True Cases, one showing the False cases.
So I set the I.P. address, set "Connect?" to true, and run my code for a while. I then set "Connect?" to false, change the I.P. address, and then set "Connect?" to true.
What I have found is that the "TCP Close Connection" does not actually close the connection, and the "TCP Read" and "TCP Write" are reading and writing to BOTH I.P. addresses simultaneously! (confirmed by using Wireshark). I don't understand how this can be since I only have one TCP Write and one TCP Write, and see only one "Connection I.D." when I probe that wire.
Am I not closing the connection properly? Do I have to kill the connection ID in Windows somehow?
Any ideas would be appreciated.
Thanks in advance,
Mike
Using Labview 8.2
Windows XP
Attachments:
Ethernet Issue.JPG ‏274 KB

Nathand,
The code shown is a simple representation of what I'm doing. I guess it wasn't clear. The switch is connected to a shift register to compare the previous & current loops itterations and only opens one connection "on change" of the "Connected?" input. (that is confirmed with Wireshark). Also, the product tells me that I have made only one TCP/IP connection on each IP address.
I pass the Connecion ID that is created out the right side of the loop and into the left with a shift register when the connectionis made...so the same Connection ID is used for each read/write. What I'm not understanding is how I can see only one Connection ID on the wire but a read/write to both I.P. addresses with only one one read and one write in my code.
Any other ideas would be appreciated.
Thanks,
Mike

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

FIX: FireWire communication issue solved - What worked for me

After installing the iPod Updater 2006-01-10, I found that my FireWire devices (not just my iPod) no longer worked. After much messing about with all the suggestions I found online (none of which worked) I've managed to sort out the FireWire communication issues I had.
you can read about the exact issues I had here:
http://forums.kustompcs.co.uk/showthread.php?t=35034
and here:
http://discussions.apple.com/message.jspa?messageID=1562072
Unfortunately those looking for a quick fix will be disappointed, I had to:
a) Send my iPod Mini back to Apple, which was promptly replaced
b) Totally re-install Windows (including drive format)
c) Borrow the install CD that came with my friends iPod, which had a later version of iPod Updater (2005-10-12) than the one I had on my install CD, but earlier than the dreaded 2006-01-10
If anyone needs this updater (as it's impossible to find an earlier one on Apple's website) drop me your email in here and I'll send you the web address to download it. This is basically a ZIP of the original CD, totally virus free (for those that are worried) and appears to work fine.
If Apple have an issue with this, then why don't you fix the link on your site to this updater; this is simply my response to the complete lack of response from Apple on this matter.
A quick note about the: 'connection rate=S100 ERROR'.
If you discover you have this error when you test your iPod in diagnostic mode; find out how to do this here:
http://www.methodshop.com/mp3/ipodsupport/diagnosticmode/index.shtml
Then it appears there is nothing you can do to fix this other than sending it back to Apple. No amount of restoring will solve it.
I hope this helps someone out there! I've yet to fix the issue with my LaCie drive (basically it needs sending back) which if anything proves that whatever screwed my system did something to the hardware on a low level, it wasn't a Windows software issue, because after re-installing it, I download SP2 and ALL the latest hotfixes, if that was the cause, it would have done it again.
This leaves one culprit - the iPod Updater 2006-01-10, as this was the only software I installed at the time both of my FireWire devices went down, avoid it like the plaque.
Regards
Matt

After installing the iPod Updater 2006-01-10, I found that my FireWire devices (not just my iPod) no longer worked. After much messing about with all the suggestions I found online (none of which worked) I've managed to sort out the FireWire communication issues I had.
you can read about the exact issues I had here:
http://forums.kustompcs.co.uk/showthread.php?t=35034
and here:
http://discussions.apple.com/message.jspa?messageID=1562072
Unfortunately those looking for a quick fix will be disappointed, I had to:
a) Send my iPod Mini back to Apple, which was promptly replaced
b) Totally re-install Windows (including drive format)
c) Borrow the install CD that came with my friends iPod, which had a later version of iPod Updater (2005-10-12) than the one I had on my install CD, but earlier than the dreaded 2006-01-10
If anyone needs this updater (as it's impossible to find an earlier one on Apple's website) drop me your email in here and I'll send you the web address to download it. This is basically a ZIP of the original CD, totally virus free (for those that are worried) and appears to work fine.
If Apple have an issue with this, then why don't you fix the link on your site to this updater; this is simply my response to the complete lack of response from Apple on this matter.
A quick note about the: 'connection rate=S100 ERROR'.
If you discover you have this error when you test your iPod in diagnostic mode; find out how to do this here:
http://www.methodshop.com/mp3/ipodsupport/diagnosticmode/index.shtml
Then it appears there is nothing you can do to fix this other than sending it back to Apple. No amount of restoring will solve it.
I hope this helps someone out there! I've yet to fix the issue with my LaCie drive (basically it needs sending back) which if anything proves that whatever screwed my system did something to the hardware on a low level, it wasn't a Windows software issue, because after re-installing it, I download SP2 and ALL the latest hotfixes, if that was the cause, it would have done it again.
This leaves one culprit - the iPod Updater 2006-01-10, as this was the only software I installed at the time both of my FireWire devices went down, avoid it like the plaque.
Regards
Matt

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.

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.

Any fix for the PC based network printer communication issue with Mavericks?

Any fix for the PC based network printer communication issue with Mavericks?

I just signed up for FIOS and am not experiencing your problem (had enough other ones instead).
Go to mail preferences ~ click on a mail account ~ click on the advanced tab. The only settings that worked for me were: port 110 SSL OFF, authentication: Authenticated POP (APOP). If I remember correctly when I first set this up another window opened and I typed in my password and never had to do that again.
Hope this helps.

Nexus1000v - ? communication issue vcenter - N1Kv ???

Unregulary we get these kind of alarms in our vcenter although there were no changes made on nexus or VM side.:
"vSphere HA detected that host HOSTNAME is in a different network partition than the master MASTERNAME"
They are cleared after a certain time without any manual action.VMware assumes a communication issue between vcenter and nexus1000.
Anyone with similar experiences (or even a solution)???

Hi Sachin,
Thanks for your response.
Please find my reply below:
Is the module showing as up in the VSM when you execute 'show module'?
>Yes the module is up and showing active when i execute the given command
Is you ESX management VLAN allowed on the access port profile and on the uplink? Is it created on the switch?
>Yes it is created on the vswitch as well as the upstream switches and allowed in the link also.
Do you have system VLANs for your control, packet connectivity? For your ESX mgmt connectivity?
> Yes i had defined control, packet and management vlans as system vlans.
I feel that the port profile is not allowing the traffic to go in and out from the DVS.
When i change the uplink of VSM from vswitch to DVS then the VSM doesnt reach gateway itself.
Thanks,

Welcome to the LabVIEW Communications Discussion Forum!

All,
Welcome to the discussion forum for LabVIEW Communications System Design Suite! This is an open forum for users of LabVIEW Communications to share their product related questions and knowledge with each other. Like our other NI discussion forums, NI engineers will be active in helping to resolve questions and provide feedback.
For getting started materials, tutorials and example code, try visiting the SDR Community.
Nick C | Staff LabVIEW Platform Product Support Engineer | National Instruments

You are still posting in the wrong forum and in an unrelated thread. This forum here is about software defined radio (SDR).
LabVIEW Champion . Do more with less code and in less time .

Xi3 companion box communication issues with X1 platform

Hopefully someone has had this issue as I haven't been able to find this one during my search.   Subject: Xi3 set top boxes will not connect to the X1 platform on the same outlet(s) that my RNG150 will.   Background: 4 weeks ago a very polite gentleman working with an Xfinity subcontractor arrived at 8am to install our Xfinity package and equipment. 8 hours later he finally left. During that time, there were multiple connectivity issues with the small Xi3 set top boxes. The X1 platform (DVR) and modem were easily set up and tested and worked perfectly (and still do) at the main location in our great room, however, when it came time to connect the other 3 rooms (all located upstairs), there were communication issues. As my wife set up services with Xfinity, she didn't realize we needed these extra set top boxes, so the technitian had to call and add them and only had (2) of the "new" Xi3 boxes, but had an "older" RNG150 set top box in his vehicle so we had him install that one as we didn't mind the older larger box in the rec room. After multiple calls to trouble shoot why these two boxes weren't communicating, he apparently resolved the issue, tested the boxes and we signed off and he left. That evening I went to turn on the bedroom tv and nothing but the red screen of death. Error code RDK 03030. So, I followed the troubleshooting guildlines, rebooting the platform in sequence, several times to make sure I got it right. Still red screen. I checked the other Xi3 box, same issue. Since the rec room tv was still working, I just jacked that box and moved it to our bedroom. BOOM. Full functionality. Only problem was the inability to access our saved programs. So, i've been doing this for the last 4 months. Moving the box from our room to the rec room for our little one to watch cartoons, then back to our room at night. Suffice it to say, my wife is growing tired of this so I put a call into the technician as he wanted to make sure I call him first so the install doesn't look negative on his record. No response. I've been researching this for the last week and have come to the following conclusions. - Possible wire/coax issue.This seemed the most plausible, however, I was able to confirm we have the COMMSCOPE Amp installed and the line to the X1 platform does in fact work based on the fact the older box works on the same line, so if it is some sort of wiring issue its lost at the Xi3 box or perhaps the older box requires a weaker signal to perform? I've also seen many comments suggesting the COMMSCOPE amps are garbage. Thats fine, but if it worked previously, and the older box works, would that still be the culprit?
- Moca issue.I'm not entirely sure how this works, but when checking diagnostics, the grid shows 0's across the matrix. Even with the older box active. I'm at work currently so I cannot post the rest of the diagnostics, can provide that once I get home.- Hardware issue. Even though these boxes worked when the technician installed and tested them, perhaps there is a hardware failure or these boxes are "bad".   Hopefully someone on here can help, I'd prefer not to have to contact customer service, follow all the trouble shooting steps I've perfomed ad nauseum and have a tech come out if possible. However, if it has to happen then so be it. Thanks for your help in advance.

Hopefully someone has had this issue as I haven't been able to find this one during my search.   Subject: Xi3 set top boxes will not connect to the X1 platform on the same outlet(s) that my RNG150 will.   Background: 4 weeks ago a very polite gentleman working with an Xfinity subcontractor arrived at 8am to install our Xfinity package and equipment. 8 hours later he finally left. During that time, there were multiple connectivity issues with the small Xi3 set top boxes. The X1 platform (DVR) and modem were easily set up and tested and worked perfectly (and still do) at the main location in our great room, however, when it came time to connect the other 3 rooms (all located upstairs), there were communication issues. As my wife set up services with Xfinity, she didn't realize we needed these extra set top boxes, so the technitian had to call and add them and only had (2) of the "new" Xi3 boxes, but had an "older" RNG150 set top box in his vehicle so we had him install that one as we didn't mind the older larger box in the rec room. After multiple calls to trouble shoot why these two boxes weren't communicating, he apparently resolved the issue, tested the boxes and we signed off and he left. That evening I went to turn on the bedroom tv and nothing but the red screen of death. Error code RDK 03030. So, I followed the troubleshooting guildlines, rebooting the platform in sequence, several times to make sure I got it right. Still red screen. I checked the other Xi3 box, same issue. Since the rec room tv was still working, I just jacked that box and moved it to our bedroom. BOOM. Full functionality. Only problem was the inability to access our saved programs. So, i've been doing this for the last 4 months. Moving the box from our room to the rec room for our little one to watch cartoons, then back to our room at night. Suffice it to say, my wife is growing tired of this so I put a call into the technician as he wanted to make sure I call him first so the install doesn't look negative on his record. No response. I've been researching this for the last week and have come to the following conclusions. - Possible wire/coax issue.This seemed the most plausible, however, I was able to confirm we have the COMMSCOPE Amp installed and the line to the X1 platform does in fact work based on the fact the older box works on the same line, so if it is some sort of wiring issue its lost at the Xi3 box or perhaps the older box requires a weaker signal to perform? I've also seen many comments suggesting the COMMSCOPE amps are garbage. Thats fine, but if it worked previously, and the older box works, would that still be the culprit?
- Moca issue.I'm not entirely sure how this works, but when checking diagnostics, the grid shows 0's across the matrix. Even with the older box active. I'm at work currently so I cannot post the rest of the diagnostics, can provide that once I get home.- Hardware issue. Even though these boxes worked when the technician installed and tested them, perhaps there is a hardware failure or these boxes are "bad".   Hopefully someone on here can help, I'd prefer not to have to contact customer service, follow all the trouble shooting steps I've perfomed ad nauseum and have a tech come out if possible. However, if it has to happen then so be it. Thanks for your help in advance.

.vi files access using Labview Communication Suite

Can't I access labview files from Comm Design suite?
What I see is it has got all the functionality I would be needing to program a USRP which I other wise use to do with Labview. Why .vi files are not being supported by cmm suite?
2. If I want to design a system comm suite is enough or I still need to buy Labview Package?

Hello Wired_,
With regards to your second question, LabVIEW Communications will allow you to design, develop, and test your communication algorithms. With this software, you will not be able to build your application into a executable format outside of LabVIEW Communications.
Regards,

About the communication issues in the client-server program

About the communication issues in the client-server program
Hi, I have some questions about the communication issues in a java project, which is basically the client and server architecture. In brief, the client, written in java, can be deployed anywhere, and in the following part, assume it is in the LAN (Local Area Network) which is connnected to the internet through the firewall and/or proxy, and the server, written in
java too, simply provides the listening service on a port in a remote machine. And assume the server is connected to the internet directly so that the scenario can be simple to focus on the core questions.
My questions are as follows:
1 About the relationship between the communication port and protocol
Generally, protocols at the application level like HTTP, FTP have their own default port, e.g., HTTP is corresponding to 80,
FTP is to 25. But it is NOT necessary for the web server to provide the HTTP listening service at port 80, right? E.g, Tomcat provides the HTTP listening service at 8080. So it means the default relationship between the application protocl and their port is some routine, which is not necessary to follow, right?
2 Assume a LAN connected to the internet through a proxy, which only allows HTTP protocol, then questions are:
2.1 Does the proxy recognize the HTTP request from the client by the port number (carried in the request string)? For example, when the server provides the HTTP listening service at 80, then the request from the client will include the port number 80, then the proxy will parse such info and decide if or not the request can be out.
2.2 Does the proxy recognize the HTTP request from the client by protocol (carried in the request string)? For example, the protocol used in the communicatin should be included in the request, then the proxy can parse it to make the decision.
3 In java programm, if using the HTTP protcol, then on the client: the corresponding API is java.net.URLConnection, right?
If using the TCP protocol directly, then on the client:the corresponding API is java.net.Socket, right? In both cases, the server side use the same API, java.net.ServerSocket?
Is it correct to say that the communication by Socket is faster than URLConnection?
4 Take MSN messenger for example, which protocol does it use? Since proxy configure is only the possible option, so I guess generally the TCP protocol is used directly so that the better perfomrance can be achieved, right?
5 Given 3 computers within the same LAN, can the client, proxy, server environment above be correctly simulated? If so, can
you recommend me some typical proxy program so that I can install it to configure such an enviroment to perform some test?
6 I guess there should be some software to find out which port number a given program/process is going through to connect to
the remote machine, and which port number a given program/process is listening on? Also, what protocl is used in the given
communication.
7 Finally, regarding each of the above questions, it will be highly appreciated that if you can recommed some references,
tutorials, books etc. In summary, what I care about is how to enable the java client behind the proxy and firewall to
communicate with the remote server without problems, so if you know some good tutorials plz let me know and thx in advance!
Finally, thanks for your attention so such long questions =).

FTP is to 25. But it is NOT necessary for the web
server to provide the HTTP listening service at port
80, right? E.g, Tomcat provides the HTTP listening
service at 8080. So it means the default relationship
between the application protocl and their port is
some routine, which is not necessary to follow,
right?Not sure what you're saying here.
There must be a server listening on some port. The client must know what port that is. If you open the connection using the Socket class, you'll explicitly specify the port. If you use some higher level class like URLConnection or something in the commons Net package, there's probably a default port that will be used if you don't explicitly specify another.
There's no way for the client to know that the HTTP request will go to port 80 instead of port 8080. If you think the the client contacts the server without explicitly naming a port, and then asks the server "get me your HTTP server", and the port is determined from that, you're mistaken.
Not sure if you're thinking that, but it sounded like you might be.
2 Assume a LAN connected to the internet through
a proxy, which only allows HTTP protocol, then
questions are:
2.1 Does the proxy recognize the HTTP request
from the client by the port number (carried in the
request string)? For example, when the server
provides the HTTP listening service at 80, then the
request from the client will include the port number
80, then the proxy will parse such info and decide if
or not the request can be out. I'm not sure, but I think most proxies and firewalls are configured by ports. I thought I'd heard of more sophisticated, higher-level ones that could understand the content to some degree, but I don't know anything about those.
3 In java programm, if using the HTTP protcol,
then on the client: the corresponding API is
java.net.URLConnection, right?That's one way.
You might want to look into this:
http://jakarta.apache.org/commons/httpclient/
If using the TCP protocol directly, then on the
client:the corresponding API is java.net.Socket,
right? In both cases, the server side use the same
API, java.net.ServerSocket? A Java client will user Socket, and a Java server will use ServerSocket and Socket.
Is it correct to say that the communication by Socket
is faster than URLConnection?Probably not.

2253iX California Power Supply USB Communication Issue FIXED

I figure I would post this in the event someone else runs into the same issue.
When trying to communicate to an 2253iX California three phase power supply through USB using labVIEW, it would always fail in the initalization block, when asking the unit for the model ( *IDN? ). The display on the instrument would display Error -113 "Undefined Header" Turns out the USB Com port driver doesn't work when registered as COM9 or greater. It has to be COM0 through COM8. Uninstalling a device in that range and reassigning the power supply's COM fixed the issue.

not surprising...
I have been using California Instruments 5001iX AC source and 3091LD AC load for years and communications (RS-322, GPIB, USB) have always been hit and miss when answering an *IDN? query.
Even the newer series 2 models have these issues, but seemingly only with *IDN? query.
I just put a loop in to query it several times before giving up.
Also I have found Ci's set of IVI vi's are usless crap and have made my own using SCPI that work a lot better.
What really makes me sad is Ci is still far superior than Elgar when it comes to AC power sources.

Field Point FP-1000 communication issue - Device found but offline in MAX

Hello,
I am trying to control several field point PLCs in a level tank. They are communicating through a FP-1000 module. I am able to add the devices through a configuration file in MAX. But there is an error saying " The device is offline. Make sure the device is connected and its power is on. " All of the field point PLCs have green light on for both " Power" and "Ready". I am not sure what the issue is here. I am using Labview 2014 and Field Point , VISA drivers are installed. Please see attached pictures for details.
Many Thanks
FLiu
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Thanks for your reply. I installed the most updated version for both ones. It turns out the configuration file for FP-1000 bank points to the wrong COM port for the Serial communication. I am able to communicate with the system now. I do have another problem through. I only have excutable labview files and a configuration file for the control system that I am working with. The original VI project file were lost. After importing the right configuration file in MAX, I installed the excutables and tried to run it. There is no response at all.The labview only last a few seconds and stopped. Any thoughts are greatly appreciated.
Thanks
Fliu

Tshark LabVIEW Communication Issue

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