Retrieve web-based data using RT Target

[Jolt]

Hello all,

Specifically, I have an instrument that published a "website" with feedback information. I would like to be able to read this from a cRIO. This is very straightforward in Windows with examples such as "weather" using ActiveX and "atomic clock" using DataSocket.

Unfortunately it seems that when deployed on a RT target, DataSocket does not support HTTP.

Any suggestions?

BTW, this instrument also supports Web Services using SOAP - Again, a no brainer in Windows with the Web Services Wizard (tools>>import>>web service...) but also NFG on the RT...

[LAVA 1.0 Content]

QUOTE (Jolt @ Apr 9 2009, 12:54 PM)

Specifically, I have an instrument that published a "website" with feedback information. I would like to be able to read this from a cRIO. This is very straightforward in Windows with examples such as "weather" using ActiveX and "atomic clock" using DataSocket.

Unfortunately it seems that when deployed on a RT target, DataSocket does not support HTTP.

You can implement HTTP requests (both GET and POST) using the low level TCP functions in LabVIEW, and these will work also in RT. I have some examples at work that I can post tomorrow.

The http://forums.lavag.org/Posting-to-Twitter-from-LabVIEW-t13024.html&pid=57632' target="_blank">Twitter status VI I posted a while back is based on one of these.

[Rolf Kalbermatter]

QUOTE (Jolt @ Apr 9 2009, 02:54 PM)

Hello all,

Specifically, I have an instrument that published a "website" with feedback information. I would like to be able to read this from a cRIO. This is very straightforward in Windows with examples such as "weather" using ActiveX and "atomic clock" using DataSocket.

Unfortunately it seems that when deployed on a RT target, DataSocket does not support HTTP.

Any suggestions?

BTW, this instrument also supports Web Services using SOAP - Again, a no brainer in Windows with the Web Services Wizard (tools>>import>>web service...) but also NFG on the RT...

All these things are one of the reason to not use ActiveX or .Net for things that can be solved otherwise. The HTTP protocol on the client side is not that terribly complicated to not implement it directly in LabVIEW.

LV_FPGA has posted his code. In the CVS repository on OpenG are some HTTP Vis too, that haven't made it into a released OpenG package yet.

Rolf Kalbermatter

[Jolt]

QUOTE (LV_FPGA_SE @ Apr 9 2009, 10:42 PM)

You can implement HTTP requests (both GET and POST) using the low level TCP functions in LabVIEW, and these will work also in RT. I have some examples at work that I can post tomorrow.

The http://forums.lavag.org/Posting-to-Twitter-from-LabVIEW-t13024.html&pid=57632' target="_blank">Twitter status VI I posted a while back is based on one of these.

Thanks! I started to play with direct TCP this last night - Unfortunately I was not successful so far, probably do to company firewall issues.

Any other examples very much appreciated and I'll work on getting code out of the CVS system soon.

BTW, I agree with rolfk - I would rather understand what I'm doing and use low-level functions, especially for simple tasks, but I haven't quite figured out all that network protocol stuff...

[LAVA 1.0 Content]

Attached are my low level LabVIEW VIs for HTTP GET and HTTP POST.

Download File:post-3370-1239397633.vi

Download File:post-3370-1239397638.vi