TCP Read returns no error and zero bytes

[endeavor]

Hi Mark,

yes, it's Win 7.

[User002]

A agree - this sounds like odd behavior.  Have you tried running NI IO Trace?  That might be about as good as a Wireshark in this case.

[endeavor]

Hi Andrew,

I haven't—at the moment it's impossible due to the absolute remoteness of my debugging.

[User002]

Could you by chance upload a version of your code with the IO Trace VIs in it, to activate the scan?

[endeavor]

Amazing results, guys.

I've received the log file containing the error source text (in case of I'm getting a warning), [comma] and TCP Read real execution time calculation (ms).

Here it is:

,0

,1

,1

,1

If I'm not stoned this means TCP Read does not wait for 30 s/5 bytes, returns no error, no warning and zero bytes.

How could this be?

[PhillipBrooks]

Could the source of the TCP data be sending some sort of message with no data, maybe as an application layer 'keep alive' signal?

What port are you using, is it for a well known service?

[endeavor]

Hi Phillip,

thanks for your reply. I'm using the port which is not mentioned as a port for a well known service. The source of the TCP data is a complex module with its own closed source software so I can't say anything confident—in my opinion, it shouldn't send any keep alive messages. But even if does, my question is why TCP Read doesn't wait for 5 bytes/30 s?

[Mark_Yedinak]

Have you tried taking a network trace and see what is happening with the network traffic?

[isaacvega]

Did you ever solve this issue, I am having a similar problem to this one.