Data socket server hangs when a 2nd reader is added

[rajman]

Hello All:

I have a program that has 2 writers and 2 readers (all 4 different computers with separate IP addresses).  I use the Data Socket Server program for the writers to send data to the readers.  Until recently, this setup had been working great.  I noticed now that the Data Socket Server program works well only when I have one reader (with the 2 writers).  As soon as I connect the second reader, the Data Socket Server program hangs.

I downloaded the latest LVRunTimeEng (version 7.1.1) and installed it to get the latest Data Socket Server.  The computers are running Windows XP Pro SP2.  Any advice is appreciated.  Thank you.

Raj

[nandini]

The datasocket server accepts upto 50 connections so I am not sure why this error occurs.
- Does the program hang when a specific reader is added or any one of the two are added as the second reader.
- Where are you running the datasocket server, in the reader or writer computer?
- Does the program work with two writers and one reader, if so what information does the reader get?
- Is a specific reader designated to a specific writer ?

Thank you

Nandini
NI

[rajman]

Nandini:

Thanks for the reply.  Here are the answers to your questions:

1. The Data Socket Server runs on a Reader computer.

2. Everything works when I have 2 writers and 1 reader.  The Data Socket Server program runs on the same computer where the reader program is running.

3. A specific reader is NOT designated to a specific writer.

4. Data Sent from the writers is "variant" data (in Visual Basic 6.0).

5. When I connect the second reader (which is on a different computer than the Data Socket Server and the 1st reader program), the Data Socket Server "hangs".  The connection process is very very slow.  This procedure used to work very well, say, up to early this year.

I did some addl testing and narrowed down the problem.  I ran the Data Socket Server on one computer.  Then I ran the reader program on a second computer.  The connection was very very slow, giving the appearance that the Data Socket Server is "hanging".  I did not run any writer programs.

Raj

[nandini]

Is it only a specific computer that is causing this slow connection/hang to happen or are you able to replicate the problem on all the computers you run data socket server on?

Thank you

Nandini
NI

[rajman]

Nandini:

I swapped the computers (that are the readers) and tried the following.  Run Data Socket Server on first computer and the reader program on the second.  Then run Data Socket Server on second computer and the reader program on the first.  In either case, the Data Socket Server program was connecting very very slow.  Just so you know, the two computers are connected on a LAN via a Linksys access point router (model number BEFW11S4).

Raj

[nandini]

Hi Raj:

I am working on trying to find you a solution for this problem. In the meanwhile I though this article would be of interest to you.

http://zone.ni.com/devzone/conceptd.nsf/webmain/f3c85234f1075ea986256caa005a0136

Thank you

Nandini
NI