Tcp connection limiting ?

Hi,
just wondering how i can restrict connections to oracle to a certain number of ip addresses..and deny the rest. connections via JDBC/ODBC and such.

You can use packet filtering option in Cisco routers and so on.
True men can do it by protocol.ora

Similar Messages

Forefront TMG disconnected a non-TCP connection

Hi,
I am getting the following error alerts in TMG
Forefront TMG disconnected a non-TCP connection from 192.168.0.1 because the connection limit for this IP address was exceeded. Larger custom connection limits should be configured for the IP addresses of chained proxy servers and back-to-back Forefront
TMG computers with a NAT relationship.
This error show two msgs for my both dns servers.
My DNS servers Ip addresses
192.168.0.1
192.168.0.2
Please help me out
Thanks

Hi,
How about editing the Maximum non TCP sessions per second per rule setting?
For more information:
http://technet.microsoft.com/en-us/library/dd441028.aspx
Best Regards,
Joyce
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Max number of TCP connections to one IP?

Is there any limit, imposed by the TCP protocol, to the number of active connections to one IP address on one interface?
I'm asking this because it's easy to add more servers behind a load balancer, but I wonder if the TCP protocol limits in some fundamental way the number of connections to the load balancer itself.
Let's say there's an ACE 4710 load balancer in front of a bunch of Web servers. The balancer exposes one IP address to the clients on the public network. The connections are forwarded to the Web servers on the private network. The balancer is also doing NAT: the servers see the connections originating on a private IP on the load balancer.
On the client side, each connection is uniquely identified by the quartet (source IP, source port, dest IP, dest port). So as long as each client only creates one connection, I think the limit here is just the amount of RAM on the load balancer.
On the server side, same thing, each connection is identified by the same quartet, so I guess the theoretical limit here is 64k connections per server, due to the limit imposed by the source port numbers on the load balancer.
OTOH, if the load balancer is not doing NAT (the servers see the connections originating on the public IPs of the clients), then there should be no limit imposed by the TCP protocol.
Is that right? Comments?

you got it right.
Gilles.

How to limit the number of TCP connections beeing used concurrently while a page is beeing loaded?

We manufacture industrial small-footprint control modules with embedded web server. The resources of these modules are very limited, especially in RAM. We have problem, that FF opens 15 parallel TCP connections while loading a web page (main html page first, then all icons simultaneously). We can not handle such behavior because of lack of RAM memory needed for TCP buffers.
Question is how to limit the number of concurrent TCP connections the browser will use? We need to do it somehow directly from the page, we can not push our customers to change the general settings of their browsers (they would not understand such things anyway).
Do anyone have any suggestion?

Sorry, one other thought. Many web designers now combine all icons into a single image and use CSS to clip the image so that only the desired portion is displayed. This minimizes the number of required connections and increases the probability that the image can be retrieved from cache.
More info:
* [http://www.w3schools.com/css/css_image_sprites.asp CSS Image Sprites - W3Schools]
* [http://www.alistapart.com/articles/sprites/ A List Apart: Articles: CSS Sprites: Image Slicing’s Kiss of Death]
* [http://coding.smashingmagazine.com/2009/04/27/the-mystery-of-css-sprites-techniques-tools-and-tutorials/ The Mystery Of CSS Sprites: Techniques, Tools And Tutorials | Smashing Coding]
No idea whether this is practical for your application.

Azure Worker Role can't receive tcp connection to Port 25(Smtp)

I have an SMTPE implementation as an Azure Worker Role. I have defined two input endpoints (port 25 and port 2525). Listener at 2525 accepts tcp connections from smtp clients. However port 25 can't receive connections.
When running on emulator port 25 works fine. This issue occurs when I publish my worker roles to the cloud.
I use the same code for both. InputEndpoints are also defined the same way. The only difference is the port number.
Is there any limitation related to port 25?

hi sir,
Base on my experience, Azure platform don't support out-of-the-box mail server. So I am not sure you can use SMTP on Azure cloud service. but I recommend you could refer to the
sendgrid .Also, you can follow this documents:
http://blog.smarx.com/posts/emailtheinternet-com-sending-and-receiving-email-in-windows-azure
Regards,
Will
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ACE: VIP Out of service, Still accepts TCP connections

Hi Guys. I am looking at a issue with an ACE. SW is 3.0(0)A3(2.6)
We have a setup where most of it appears fine. It detect the loss of rservers, probes fail, the VIP stops responding to Pings, but it still accept TCP connections, even though there is nothing behind to accept them.
The question is, is this correct behaviour? and if so is there any reference I can look at to confirm?
While this behaviour is inconvenient for us. I can see why it may actually be correct.
Thanks,
Paul.

Hello Paul,
This is expected behaviour for L7 LB connections:
The 'down' VIP will reply to SYN requests, but will then send a RST packet.
This is because the ACE doesn't know what to do with the L7 connection until it has been build up. Only when the L7 connection is 'open' we notice that all the vserver which could serve this request are down.
So it is correct and expected, but not exactly desired. It's just a side effect of the design. So far I do not known of any plans to change this behaviour. However similar limitations have been addressed in the past, like: CSCsq17137.
Hope this helps, Peter

Random TCP connections created in Selector.open (in NIO)

I'm currenlty running a production app which has several independently running application server classes going at any given time. Each of these uses one Selector to provide support for asynchronous I/O operations. Lately I noticed that when bouncing one of these servers I'd have problems bringing it back up because of sequential "ghost listeners" and "ghost connections" colliding with the ports I was interested in.
So, I got out a local port-scanner and did some digging. To my chagrin I discovered that every time I made a call to Selector.open() a new TCP connection was made from my application to my application on an internal port. In Java 1.4.2_02 this occured on the "primary" network adapter. In Java 1.5 this occured on the loopback adapter. Unfortunately for me neither is acceptable because my app regularly binds and unbinds for listening on varying adapters including the wildcard adapter (0.0.0.0) and I can't have my own process colliding with itself trying to listen to ports.
Okay, so then I did some forum searching with the help of a couple co-workers. It turns out these connections are "normal" and related to something called the "wakupPipe", or "wakup pipe". Also, this seems somewhat related to something we call the "runaway select event" in-house (where Selector.select(x) returns 0 before the timeout is up over and over again, which we've long since worked around to support Java 1.4.2_02).
This problem occurs on windows 2000 and windows server 2003. I've attached a code-snippet below that will duplicate the problem (and flood a system with extraneous TCP connections if left running long enough).
My questions are:
1) Why in the world did this wakup pipe have to be implemented as a TCP connection (rather than in-memory)?
2) Why is this not documented anywhere in the Java API's, or am I missing the documentation of it?
3) Is there some way to control the behaviour of this "wakup pipe"? (ie: make it be in-memory only, a file, or specify port-range, IP etc...)
4) Isn't it dangerous to create a library based on undocumented and randomly allocated TCP connections that can't be controlled via configuration?
import java.nio.channels.Selector;
import java.util.ArrayList;
public class NIOSelectorOpenExample implements Runnable {
    protected boolean shouldRun = true;
    public void shutdown() { shouldRun = false; }
    public void run()
      try {
        ArrayList selectors = new ArrayList();
        while( shouldRun )
            selectors.add( Selector.open() );
            Thread.currentThread().sleep(500);
      } catch (Exception ex) {
          ex.printStackTrace();
}Basically on #4 I want to know why/if running this code wouldn't be a major problem on any system that opens and closes ports for listening regularly. (And yes, aside from the fact that it doesn't explicitly clean up the selectors before exiting.)

Hmmm ...
We had an issue in production where one
of the ServerSocketChannels failed to bind because it
collided with the wakeup pipe range. Of course, this
was on Java 1.4.2_02 which binds on the primary
adapter for the system and not the loopback adapter.This seems back to front. By default Java binds to INADDR_ANY which is all the interfaces, which is why you got the collision on the loopback port which was already there. If it bound the socket to a specific non-loopback NIC there would be no collision with any loopback port, they are different number spaces.
Are you able to create all the ServerSockets before any of the Selectors?
or, if your hosts aren't multihomed, is it practical for the application to bind its ServerSockets to the primary NIC (i.e. the non-loopback)?
Yes, we can repeatedly try to bind on a port and
d perform other work-arounds, but why should we have
to? How could we have expected this behavior? (It
may be a Windows limitation that caused Sun to choose
their implementation method, but non-Java TCP apps on
windows don't have these problems...)Agreed, but then again non-Java TCP apps don't try to implement select() for arbitrary numbers of sockets to agree with *nix platforms, they can generally live with <= 64.
Note: The problem appears exacerbated from having the
listen ports of these wakeup pipe connections stay
open for long periods of time (rather than closing as
soon as the pipe is established). Would this help? There would still be the connected port with the same number & this might inhibit a new listening port with that number. Haven't tried this myself.
Well, considering the behavior changed between
1.4.2_02 and 1.5 it can't be all that inaccessible a
fix. Perhaps using an extra TCP connection was
necessary in some cases, but obviously binding to
("127.0.0.1", 0) isn't the only choice since it has
changed recently and those values could easily be
made configurable (given access to the code
involved).It changed from binding to 0, i.e. INADDR_ANY, in 1.4 to binding to 127.0.0.1 in 1.5, probably in an effort to vacate the port space for the physical NICs.
Given access to the code involved you can change anything. In the SCSL code it is sun.nio.ch.WIndowsSelectorImpl.java in src/windows/classes.
Actually, I'm also wondering if a single
(known-default/configurable) listen port wouldn't be
adequate for all of these wakeup pipe TCP
connections. Me too.
Regards
EJP

Flush TCP connection

Hello,
I am trying to capture data from the TCP connection, however, there are instances where I may only have say 5kbytes of data and when I have a lot more. If I take the 'bytes to read' beyond 6000, the program hangs.
Is there some way to flush the TCP connection so that when I send the next set of commands over the TCP connection, I can just capture the current set of data instead of the whole bunch of data that is sent from my machine?
To give you a better understanding of my overall program, I am testing out a device over TCP. Only if I reset the device and send a read command, I get some of the data from my attached program. Because I am just limited to setting the 'bytes to read' to 6000, I cannot capture all the data. Is there another way to caputure all the data after the device reset?
Thanks,
hiNi.
Attachments:
TCPIP test for email.vi ‏36 KB

TCP has several mode inputs that you should look at and understand. The online description is pretty conclusive about them.
Basically your read function does not hang but waits for the specified timeout which by default is set to 25000 ms. There is nobody that forbids you to specify a different timeout. For instance TCP Read with a timeout of 0 or 1 will return instantaneously no matter how much data is available. Together with the mode Immediate, this will flush whatever data is present if you use a big enough number of bytes to read. You can verify that the number of bytes returned is smaller than what you have specified to read and if that is not the case issue another read with the same conditions until you receive a buffer that is smaller than you specified to read.
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions

WAE-512-1G Optimized TCP Connections

Hi all,
Regarding the Sizing Capabilities of a WAE-512-1G Appliance, what is the meaning of the "Optimized TCP Connections" ?
Is this parameter related only from the initiated point ? or from both directions?
I'm asking this because, after instaling in inline configuration, a point-to-point circuit only, (2 WAE's + 1 CM), in the Branch WAE we had a Minor Alarm saying that we have reached the TFO Limitation, and on the ohter end, we haven't that alarm.
Most of the traffic(connections), should be from the Branch to the Central Site.
So, the main question is, if this parameter is related to from where the connection is initiated.
Best Regards,
Bruno PetrÃ³nio

The branch Cisco WAE applies a new TCP option (0x21) to the packet if the application is identified for optimization by an application classifier. The branch Cisco WAE adds its device ID and application policy support to the new TCP option field. This option is examined and understood by other Cisco WAEs in the path as the ID and policy fields of the initial Cisco WAE device. The initial ID and policy fields are not altered by another Cisco WAE. The packet is forwarded to the branch router and then to the WAN.
http://www.cisco.com/en/US/docs/solutions/Enterprise/Data_Center/App_Networking/citrixdg_final.html

Router closes TCP connection after 30 minutes

I have recently replaced my D-Link DIR-100 router with a Cisco Linksys RV042, but unfortunately there seems to be a problem with it.
I have an external TCP connection coming in to a local service, and I therefore set up the router to redirect the incoming connection for the given port to the local PC hosting the service. This worked perfectly. I also opened the Firewall access rules to allow all data from WAN2 to be propagated through. This also worked just fine, and I can connect from the internet to the local PC, just like I could with my old router. Unfortunately this is where the simularities stop. When there is no communication on the TCP connection for more than 30 minutes then the router closes the connection automatically. This is NOT what I want. I only communicate on the TCP connection very rarely, but I do not want it closed automatically - at least not after just 30 minutes.
I did some research on line and it appears that there in some routers are a TCP connection timeout, which in the router I read about, defaulted to 1 day. This would be OK. I experimented and found that if there is communication every 30 minutes then it is not close the connection, but if there is 50minutes between communication then it closes the connection.
As I read that this timeout has to do with security I experimented with the firewall and found the following:
1. Disabling the entire router firewall fixes the problem !!!
2. Disabling just DoS has no effect (problem still exists)
3. Disabling SPI means I cannot connect at all !!! (new and much worse problem)
4. Disabling Block WAN Requests has no effect (problem still exists)
Is there a way to solve this problem without disabling the entire firewall, as that is not what I want to do. I have the system set up for Dual WAN (load balancing), and I only want to allow connections to a handful of ports on the one WAN, and block the other WAN entirely.
P.S. I was referred to the Cisco Small Business Support Community by the Cisco Home community, so I hope this is the right place.

Hi Ddb101,
This is a limitation (or feature depending on how you look at it) of the iPhone/iPod touch. 30 minutes after the device locks (usually 5 minutes of inactivity) the network turns off completely to save battery life. You can either turn autolock off globally, or some programs (mine for instance see: http://ootunes.com/app/ ) have an option that disables sleep while the app is running so the stream will keep playing... until your battery dies Only problem is with the screen on the battery actually dies even faster!
Finally, if the device is connected to a constant power source, it shouldn't actually time out. So if you have a way to plug it in, it shouldn't quit after 30 minutes on you...
hope that helps,
also, since there's a link to my site up there, and I sell the app, I should tell you that I might get money if you go to the page and end up buying my app...

ASA 5505:Static Routing and Deny TCP connection because of bad flag

Hi Everybody,
I have a problem. I made a VPN site-2-site with 2 ASA 5505. The VPN works great. And I create a redondant link if the VPN failed.
In fact, I use Dual ISP with route tracking. If the VPN fails, the default route change to an ISDN router, situated on the inside interface.
When I simulated a VPN fail, the ASAs routes switch automatically on backup ISDN routers. If I ping elements, it works great. But when i try TCP connection like telnet, the ASAs deny connections:
%PIX|ASA-6-106015: Deny TCP (no connection) from 172.16.10.57/35066 to 172.16.18.1/23 flags tcp_flags on interface interface_name.
the security appliance discarded a TCP packet that has no associated connection in the security appliance connection table. The security appliance looks for a SYN flag in the packet, which indicates a request to establish a new connection. If the SYN flag is not set, and there is not an existing connection, the security appliance discards the packet.
thanks!
EDIT: On the schema, The interface of the main asa is 172.16.18.148...

Check if the xlate timer is set greater than or equal to what the conn timer, so as not to have connections waiting on xlates that no longer exist. To minimize the number of attempts, enable "service resetinbound" . The PIX will reset the connection and make it go away. Without service resetinbound, the PIX Firewall drops packets that are denied and generates a syslog message stating that the SYN was a denied connection.

Opening and closing Multiple TCP connections issues

Hi all I am having an issue with the TCP VI’s and wondering if anyone has experienced this issue.
My application is required to scan 50-100 IP addresses (statically assigned) and discover if an Ethernet device is connect at that IP address. Currently I am able to achieve this by opening a TCP connection and testing the error cluster to determine if a timeout has occurred (no timeout error means Ethernet device available at the IP address). I then ensure that the TCP connections are closed.
The issue I am have is that I require a 1 second delay between the TCP open and the TCP close which significantly slows down the process. Without the 1 second delay the vi successfully connects to the device once then fails to make any TCP connect regardless of the time delay until the PC is reset.
If anyone has any advice I would be very grateful
David Barr
P.S. I have attached a simplified section of code showing this issue
Attachments:
TCP Open close issue.vi ‏15 KB

smercurio_fc wrote:
If I understand you correctly you want the time delay to be 1 second if there's a successful connection....
While I don't have a specific answer for this problem. I want to clarify for him. I believe the issue is, what if all connections ARE there? That means you keep returning a wait of 1 second 50-100 times so It takes 50-100 seconds just to initialize. I think the user is looking for a way to check for valid connections, but do so in such a way that eliminates the need for a wait which is greatly slowing things down.
CLA, LabVIEW Versions 2010-2013

Anyone else having an issue with TCP connections using iCloud for Windows?

Hi,
Before I asked this question, I did wait to see if any related questions came up, but none did, so I submit it now.
On my admittedly older laptop running Windows 7 64b Home, I've run into difficulties with the iCloud for Windows app to the extent that I had to uninstall it.
It would that, as my laptop was running, in the background, iCloudServices.exe would endlessly iterate TCP connections, which, while not actively sending or receiving any data, after some hours would number over 100 instances, taking up resources, and grinding my laptop's WiFi connection to a grindingly slow pace. I ended up, within the app, turning off everything, iCloud Drive and Photos, (I never used bookmarks), but still this would continue to occur.
I contacted Apple Support, explaining what was going on, and they stated they only dealt with IOS and gave me a Microsoft Support number. When I called Microsoft support, I came more and more to the realization that the issue was specifically with the iCloud for Windows app, as that was the only software that was endlessly creating and not closing TCP connections as it was. How was Microsoft supposed to solve an issue with Apple code?
So I called Apple back, whereupon they insisted it was a Microsoft issue. I explained other cloud services installed on the same computer were not having the same issue, it was unique to ICloudServices.exe. They stated they only dealt with IOS. I stated I purchased an iPad Air less than 7 months ago, and was trying to run iCloud in support of that. They again stated they only dealt with IOS, and suggested I again try Microsoft. I asked them if it was reasonable to expect Microsoft to solve issues with Apple code? They said regardless, there was zero support offered for anything having to do with Windows, and all I could do was uninstall the app, which I did, though that did not feel very satisfactory to me. My thinking is, if Apple writes a Windows app in support of their hardware, they should offer support for it.
Anyway, I was just wondering, is this an issue unique to me? or have others experienced a similar issue? I found this issue by opening the Windows Resource Monitor, looking under the Networking tab, and scrolling through the TCP Connections section to find 100+ concurrent iCloudServices.exe instances listed, whereas even Chrome, with multiple tabs and extensions, topped out at around 20.
My one month old Desktop, DYI, sports a solid Asus 1150 MoBo, i7-4790k cpu, 16GB Ram, and an EVGA GTX 970 video card. I list some specs only to illustrate this computer has no hardware issues in comparison to my long in tooth laptop. On this desktop, running Win 8.1 Pro 64b, at least as many, identifiably Apple, background service TCP connections are created even compared to Chrome, regardless of many tabs being open, many extensions, and even some related apps. Adobe does not even come close, though I run the full CC subscription. On this new computer, running Windows 8.1 Pro 64b, there are currently over 50 TCP connections and loopbacks that do not identify themselves, with just a - for the Image, and PID. With the experience on my laptop, I wonder how many of these are generated by Apple software, if not specifically iCloud software?
The frustrating aspect of these connections is they seem in no way active, While the Chrome and Adobe connections can be seen to be transferring data, as long as I am not running iTunes, or so have my iPad actually plugged in, it seems 99% of the time these iCloudServices.exe connections are just taking up ports, neither sending nor receiving any data discernable to me under the Processes with Network Activity, or Network Activity lists, both displayed in the same window as the TCP Connections in the Windows Resource Monitor.
Though I am fairly ignorant as regards coding, it seems as if there is no call to close a connection, very specifically, iCloudServices.exe, when it is no longer needed, and the next time a connection is needed, a new one is opened, rather than accessing the one previously opened. The only other reason I could imagine this might be occurring is if my Norton Internet Security software might mask and/or block the port after a certain time of inactivity.
Anyone out there have any ideas or advice about this? Thanks in advance.

Thanks jared,
I'm still dealing with this issue through Apple. Some time after I posted this, I contacted Apple again. They did start a case up for me, as I was experiencing the same behavior on two different machines, with two different versions of Windows.
So far it remains unsolved. I've logged iClouds for Windows on my desktop, which is brand new, then logged for awhile after completely uninstalling Norton Security Suite, depending on the Microsoft security for some time, and finally logged after I uninstalled iCloud for Windows, restarted, installed a clean download, and connected using a completely different test account, which Apple set up for me. None of this made any difference. Looking at the logs, it seems every 10 minutes, iCloudServices.exe creates a new TCP connection to confirm I'm using less than 5GB on iCloud, (which I am by a good margin, using less than 2GB), it seems this connection is not closed, and when the next iteration rolls around 10 minutes later, a new TCP connection is created. I come very close to having 6 TCP connections created per hour, until I restart my computer. This works out to... 6 x 24 = 144/day.
Perhaps the article you posted will shed some further light on this. I'm thinking seeing the state of the connection through netstats, at the least, could help.
For the last week, I've been putting a hold on further logging, as Apple wants me to create a new user account on one of my computers, install iCloud for Windows there, and log it running in the other account. This however basically means I cannot use my computer for a fair number of hours, and I've been busy enough with work the past week that I haven't the time or energy to afford to set this up and run it. I've had need of my computers too much for the past week.

TCP connection error when sending MODBUS commands to WAGO 750-881 controller after 113655 bytes of data have been sent

Hi all,
I am new to the world of labview and am attempting to build a VI which sends commands to a 750-881 WAGO controller at periodic intervals of 10ms.
To set each of the DO's of the WAGO at once I therefore attempt to send the Modbus fc15 command every 10ms using the standard Labview TCP write module.
When I run the VI it works for about a minute before I recieve an Error 56 message telling me the TCP connection has timed out. Thinking this strange, I decided to record the number of bytes sent via the TCP connection whilst running the program. In doing so I noticed that the connection broke after exactly 113655 Bytes of data had been sent each time.
Thinking that I may have been sending too many messages I increased the While-loop delay from 10ms to 20, 100 and 200 ms but the error remained. I also tried playing with the TCP connection timeout and the TCP write timeout but neither of these had any effect on the problem.
I cannot see why this error is occuring, as the program works perfectly up untill the 113655 Bytes mark.
I have attached a screenshot of the basic VI (simply showing a MODBUS command being sent every second) and of a more advanced VI (where I am able to control each DO of the WAGO manually by setting a frequency at which the DO should switch between ON and OFF).
If anybody has any ideas on where the problems lie, or what I could do to further debug the program this would be greatly appreciated.
Solved!
Go to Solution.
Attachments:
Basic_VI.png ‏84 KB
Expanded_VI.png ‏89 KB

AvdLinden wrote:
Hi ThiCop,
Yes the error occurs after exactly 113655 bytes every time. The timeout control I would like to use is 10ms, however even increasing this to 1s or 10s does not remove the error, which leads me to believe that this is not the issue (furthermore, not adding any delay to the while loop, thus letting it run at maximum speed, has shown that the TCP connection is able to send all 113655 bytes in under 3 seconds again pointing towards the timeout control not being the issue here).
I attempted Marco's suggestion but an having difficulty translating the string returned into a readable string, (rightnow the response given is " -# + ").
As to your second suggestion, I implemented something similar where I created a sub VI to build a TCP connection, send a message and then close the connection. I now build each message and then send the string to this subVI which successfully sends the command to my application. Whilst not being the most elegant method of solving the issue, it has resolved the timeout problem meaning I am able to send as many commands as I want. So in that sense the problem has been solved.
If you still have tips on how to correctly read the TCP read output, I would however like to see if I could not get my first program to work as it is slightly more robust in terms of timing.
Modbus TCP RTU is a binary protocol, as you show in your Basic VI, where you format the data stream using byte values. So you have to interprete the returned answer accordingly with the Modbus RTU spec in hand. Now what is most likely happening is that the connection gets hung after a while since you do NOT read the data the device sends as response to your commands. The TCP/IP stack buffers those bytes and at some point the internal buffers overflow and the connection is blocked by the stack. So adding the TCP Read at strategic places (usually after each write) is the proper solution for this. Is there any reason that you didn't use the NI provided Modbus TCP library?
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions

How to send joystick data over TCP connection

Hi all,
I am a long time Labview discussion forum user for learning, but this is my first time posting a question, I hope somebody can help me!
In the attached VI I am trying to send data from a joystick over a TCP connection. I can send data fine using the TCP examples (in fact the majority of my VI is just a copy of the example). However I am to the point where I do not know how to send all the data necessary (3 axis data, 12 buttons, and the POV data) over TCP. Strings, clusters, and arrays were never my strong suite and converting between them is a nightmare for me.
Basically I am trying to send each axis data (X,Y, and Z), button data (12 buttons), and POV data (the POV data will be calculated to adjust the position of a camera, so the immediate data is not important, I will add functions to add the change in the button movements to write a standing position for two servos [pan and tilt], for which that I will need to send over the TCP connection) over the TCP connection to control various cameras and motors. I don't know if it is posible to send that much data over a TCP connection in one write VI through a string, and also how to separate the string on the other side in order to control the client VI.
Again, the actual TCP communication I get, and can operate fine, just formatting all the data into a string (or whatever is required) so that I can unpack on the other side is the issue here.
Another question I have (not impotant to get the program running just might make it easier on me) is can a TCP server (which sends the data to the client) also recieve data back from the client on the same port ( for example sensor data and digital positions [on,off])? Or do I need to set up two TCP communication loops with the first client acting as the server on a different port than the first, which then sends the data to the original server, which also has a client TCP configuration in another loop? I hope this makes sense...
One final question.....I already have a solution to this but using labview for the entirety of this project would be nice. I use skype to stream 1080p video from a webcam to my computer so I can view live feed. Can labview do this? This would be awesome if so, I am just not sure if the communication protocols in use could support real time (or as close as possible to streaming) for 1080p video.
Thanks all in advance for your help,
Physicsnole
Attachments:
cameraserver.vi ‏24 KB
cameraclient.vi ‏18 KB

Physicsnole wrote:
In the attached VI I am trying to send data from a joystick over a TCP connection. I can send data fine using the TCP examples (in fact the majority of my VI is just a copy of the example). However I am to the point where I do not know how to send all the data necessary (3 axis data, 12 buttons, and the POV data) over TCP. Strings, clusters, and arrays were never my strong suite and converting between them is a nightmare for me.
Well, you cast the axis info cluster to a string, but then you cast it back to an array of DBL. Thatr's not compatible. You should probably cast it back to an "axis info" cluster of exactly the same type. Go the the other VI and right-click the cluster wire to create a constant. Now move that diagram cluster constant to the other VI and use it as type.
Your default ports don't seem to match. You seem to have client and server roles confused. In the sever you create a listener, but then you start sending packets, even though no connection is established. The connection needs to be initiated by the client.
Your client stops the loop the first time a timeout is encountered. Shouldn't that be more permanent? Also, please retain code clarity and avoid unecessary complexities. For example, replace the "not or" with a plain "or" and change the loop to "stop if true"
Physicsnole wrote:
Basically I am trying to send each axis data (X,Y, and Z), button data (12 buttons), and POV data (the POV data will be calculated to adjust the position of a camera, so the immediate data is not important, I will add functions to add the change in the button movements to write a standing position for two servos [pan and tilt], for which that I will need to send over the TCP connection) over the TCP connection to control various cameras and motors. I don't know if it is posible to send that much data over a TCP connection in one write VI through a string, and also how to separate the string on the other side in order to control the client VI.
You can send as much as you want. The casting to/from string is the same as described above.
Physicsnole wrote:
Another question I have (not impotant to get the program running just might make it easier on me) is can a TCP server (which sends the data to the client) also recieve data back from the client on the same port ( for example sensor data and digital positions [on,off])? Or do I need to set up two TCP communication loops with the first client acting as the server on a different port than the first, which then sends the data to the original server, which also has a client TCP configuration in another loop? I hope this makes sense..
The primary function of a "server" is to wait for a connection and then communicate with the client once a conenction is established. An established TCP/IP connection is fully two-way and both sides can send and receive.
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Tcp connection limiting ?

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