TCP_NoDelay.vi not working on LabView RT

[momolxg]

This VI is not available for LabView RT.
The subVI GetRawSocketFromConnectionID.vi

[momolxg]

I understand now that this property can be changed by a VISA resource ( see Example ) but am having trouble choosing the right VISA resource to see the effect of enabling or disabling the TCP(IP No delay.

Thanks

[momolxg]

This article discusses the Nagle algorithm in Labview

http://digital.ni.com/public.nsf/allkb/7efca5d83b59dfdc86256d60007f5839

The example program allows the TCP No Delay property to be changed in LabView

In the mean time you will see I have learnt to define a TCP/IP VISA resource

On Windows the delay time is reduced by setting the no delay property to false

In LabView RT an error message occurs when setting delay property to false

Property Node (arg 2) in NagleDemo-MessageSenderVisa.vi

VISA:  (Hex 0xBFFF001E) The specified state of the attribute is not valid, or is not supported as defined by the resource.

My question now > Why can I not set No Delay to false in LabView RT?

Thanks, Louis

[RobertH]

hello louis,

on RT systems the nagle-algorithm is always enabled. there is no way to diasble it.

regards,

robert h
NI germany

[momolxg]

Thanks and it seems our problems lay elsewhere.
We can now send 20s of data at 1kHz over TCP/IP without having 400ms windows of data arriving late.
Simply had to not send data to the front panel so often - still learning how to efficiently program in LabView RT.
Bye, Louis

[George_P_Burdell]

All-

These VIs do not work on Real-Time systems.  As of LabVIEW Real-Time 8.6.1, this algorithm has been turned off by default and there is no way to turn it on.  This information comes from the Real-Time R&D department.  This behavior was filed as a Corrective Action Request (CAR 123312) which was fixed with the 8.6.1 release.

Message Edited by George P Burdell on 02-15-2010 02:22 PM