Strange behavior of DataSocket server

[trajan]

Hi,

LabVIEW program is executing on  the PC computer under Win/XP.
Besides integrated web server on the same comp DatSocket server is running.
Remote clients can exchange data with server program via DataSoket. In the
LabVIEW program on the server side, DataSocket binding method is used for
connection to DS server. On the client's side a special program is written in
LabVIEW which read and writes data to DS server. I've noticed that 1 minute is
necessary for establishing connection with DS server. There are 20
controls/indicators that wirte/read data to/from DS server. Within the DS
controls/indicators a numberd IP address is defined (192.87.45.78). When client
closes application DS server is still running but doesn't upgrade values. In
that case I must  shutdown DS server enad starded again. I've removed DNS
address from the TCP/IP tab (as is suggested on this forum) but it didn't help.

The same client program works fine on the laptop which is conneted to
local LAN via wireless. When the LAN administrator assigned name to client
computer on the DNS server program works excellently. This solution is not
applicable for clients outside my company. Is there any general solution for
this problem? Why is DS server blocked if the comp IP address is not assign name
on the DNS server?

best regards

Trajan

[The_Chancenator]

Hi Trajan,

I tried responding to your email but ran into issues, but I can help you out here on the discussion forums.   I had a few more questions regarding your email.  First, are you looking for the values to update after  you have closed the client application?  I also assume that you are running an *.exe file on that client computer, is this correct?  Also, where are you looking for the values to update- in the distributed system manager?  If not, are you able to see the values update there?  Are you able to verify this both with and without the client running?

[trajan]

Hi Marti,

the answers are coming.  Yes, my client application is executable created with LabVIEW 8.6 professional version. I am looking for the value to update on the DSS server's site after I have closed client application. DS server usualy disconnects client after several minutes. During that period data are not updated (pic. DSS status) and no one client  receives updated values. When the client is finally disconnected every client receives data every seconds corectly. By the way, I'm accessing remote DS server with Remote Desktop Connection  program.

When I start client application on my desktop computer the things are worse. When I close application the DS server is totally blocked. In that case I must shutdown DS server and start again. From my home computer (ADSL 1Mbps/128kbps) after closing client application DS server disconnets me after several minutes and continue to work properly. Sometimes my inetrnet provider gaves to my comp a name and at that time program works great. But sometimes my IP assigned to my comp numeric IP address and at that time the DS server is slowdowned but is not blocked. There are no any problem when the client application is exeucuting on my laptop which is connected via wireless LAN.

I've installed client application on the 12 computers within my company and a simbolic name are assigned to all computers on the DNS server and all client's program works great, without delay and blocking DS server (pic. DSS diagnostics).

best regrads

Trajan

[pablopicassio]

Trajan, 

I have found out that the problem of slowing down connection should have been fixed in LabVIEW 2009.

Beside you can try using static IP (when you cannot set up the machine name) - should also help.

Regards,

Dawid

AE NI 

[trajan]

Hi,

I've tried my program with evaluation version of LabVIEW 2009 and the program works in the same way as with LabVIEW 8.6. The time necessary for connection with DataSocket object is approximately 5 seconds. Since my program has 20 DS objects than the total connection time is about 100 s. When connecting process is finished the program works properly. The problem  arises when the remote client closes his application. At that time DS server is still running but doesn't upgrade values.

Unfotunately, I didn't get answers on my questions:

   Why is DS server blocked if the comp IP address is not assign name on the DNS server?

   Why the program works properly when the LAN administrator  assigns name to client computer on the DNS server?

While I was waiting for your answers I was working hardly and I have found some interesting things. For 5 DS objects I've replaced the numerical IP address with host name. What a wonder, DataSocket server  was not blocking anymore. DataSocket disconnecting time was about 100 s.  With this change I've noticed another suprise: one client was treated as a two cilents on the DataSocket site. That means that DS server was blocking when the number of DS objects (controls/indicators) was greater than 15. Although, in the help file is written that the max. number of DS items is 1000. 

best regards

Trajan Stalevski