TCP write timeout

[Igor_Evdokimov]

Hi!

I'm trying to control TCP socket status by timeouts.

TCP is linking Windows server and cRIO controller both with LabVIEW applications.

As I don't know any facts about application status in my cRIO I decide to get information about physical level of connection by writing timeout and about application level - by reading timeout (if I can't send something - ethernet is not linked or socket is dead; if I did sent packet and get timeout on answer reading only - my application on cRIO is dead).

But when I disconnecting ethernet - I'm not getting writing timeout error independently of timeout value, I'm not getting any errors on writing at all; I'm getting reading timeouts only (because my system isn't getting any packets to answer) and then, after much time, error 66 on writing (I think - when my cRIO disconnecting TCP on its side and became listening TCP device by its own timeouts).

Why it's happening?

Is there any other tools to get socket status (at least on its physical level only)?

WBR,

Igor

[TheNIDragon · Accepted solution]

Hello Igor,

Unfortunately, the Timeout command for TCP Write does not function as most people would expect. This forum discussion:

http://forums.ni.com/t5/LabVIEW/quot-TCP-Write-quot-Timeout-error-56-seems-to-do-not-work/td-p/21215...

Goes through why this is and what the timeout command is actually configuring as well as different ways around this. 

Thanks!

[Igor_Evdokimov]

Thank you very much!