Anybody help?

[Tom_Zhang]

Hello guys,

I'm a engineer from China, and got a question need your help.

We have a project need TCPIP communication, and run in ths Chinese OS, it's ok. But when changed to English OS, something wrong when excute TCP open function, sometimes ok, and sometimes error occured with the error code 56. The firewall (including the system firewall), and the anti virus software are all closed. I'm confused so much. Anyone could help?

Tom

[Mark Smith]

Hello guys,

I'm a engineer from China, and got a question need your help.

We have a project need TCPIP communication, and run in ths Chinese OS, it's ok. But when changed to English OS, something wrong when excute TCP open function, sometimes ok, and sometimes error occured with the error code 56. The firewall (including the system firewall), and the anti virus software are all closed. I'm confused so much. Anyone could help?

Tom

We need more info before we might be able to help

1) are you using IP in dot notation or hostname as address?

2) are you specifiying the local port or letting the OS select the next available?

3) what is your timeout setting?

4) have you used a network packet sniffer (Wireshark) to look at the actual TCP/IP traffic?

Mark

[MikaelH]

Question, are use using any special characters in the TCP/IP strings you send, i.e. ASCII code above 127?

//Mikael

[ShaunR]

An in a similar light to MikaelHs question. Are you using a termination character to detect the end of string (and if so which one?)?

[Tom_Zhang]

We need more info before we might be able to help

1) are you using IP in dot notation or hostname as address?

2) are you specifiying the local port or letting the OS select the next available?

3) what is your timeout setting?

4) have you used a network packet sniffer (Wireshark) to look at the actual TCP/IP traffic?

Mark

1) Yes, use dot notation Ip address, but not host name.

2）Yes, and the local port is 502,Fixed and do not need the OS to select anymore.

3) Timeout set is 200ms, i thinkit's not the problem, because ever i set this to 5000ms, but still, ths error occured. I just don't know why.

4) No, i have not check this. The communication is from the PC to a module we need to control, but not another PC. Anyway i didn't try this.

I've attached the picture. Thanks for your reply.

Question, are use using any special characters in the TCP/IP strings you send, i.e. ASCII code above 127?

//Mikael

Hi MikaelH,

Thanks for your reply.

You can see my reply picture?

The error occured at the TCP/IP open stage, and nerver sent strings, so you mean when i excute the TCP open function i can check the

network bytes by some other tools?

Tom

[MikaelH]

I have one idea.

Try to stop the Service called: IPSec, does it work them?

The IPSec service controls Network access that your IT department can push onto your computer; they might stop access of your computer to any other subnet than your company's local network.

This is one way for them to limit your internet access.

I've had that problem myself.

If it works when IPSec is turned off, have your IT department to add the 192.168.0.x in the allowed subnets.

Cheers,

Mikael

[Tom_Zhang]

Hi Mikael,

It can't be that. Because The connection is just between my pc and the module we want to control.

Besides, it can get through and read back the data sometimes.

This morning i was told that when change to labview 2009, it seems ok.

Confused...

Anyway, thank you, guys. Thanks for your kind help.

Tom