http commands inLabView

[harrison1261]

We are attempting to control a Minuteman Remote Power Manager using LabView, but cannot figure out if LabView can send "http commands"
to such a device. We really need to monitor the current on our devices (after they are powered-up) to keep them from being damaged, so
we'd like a little loop that allows our software to turn the devices off if the current limits are approached. We can control the RPM through
a variety of methods, and know that it is web-accessible (and know the http commands that cycle power, etc.), it is just the lack of documentation
on TCP/IP/HTTP protocols in LabView that are holding us back.

-tom harrison

[Wiredup]

If you have the Internet Toolkit, you have the vi's now to do the trick (check your functions pallette under add-ons).

If you do not have the Interent toolkit, there are a couple of approaches. You can use the TCP functions (check the TCP pallette under the Communications group and send the commands yourself, or you can use .NET objects to get the job done.

If communication is UDP or simple TCP, then using the Communications pallette is probably best. If you need full-on http: functionality, let me know via return post and I'll share with you a .NET-based library I put together. It is not as efficient as TCP, but supports both https: and http.

[harrison1261]

We do not have the internet toolkit ($$$), so I need to use what is in LabView 8.
I would like to see/hear about your NET library.

-tom

[Wiredup]

Attached is a quickie .NET implementation of an http: document fetcher. This version does not support proxies, https, etc. but it shows the basics of how .NET can be used in LabVIEW.

This VI uses .NET 2.0. The url needs to be put in using an http://www.mywebsite.com format

The usual disclaimers go here: May be lousy code, poorly documented, may not work, etc., but feel free to start with this to make what you need. Good Luck.

Message Edited by Wiredup on 02-13-2008 04:55 PM

[harrison1261]

We are basically looking for a way to create a VI to turn on a power management board which will allow us to turn on and off our system online. If you can help us find the essential elements in this VI, or the structure it must be in, please let me know.

Jose Castellano

Maria Svenstrom

Tom Harrison

[MikeS81]

Hi harrison1261,

if you have not the internet toolkit, you can create the communication by your own. Therefore you can monitor the actual sending data by using Wireshark or somthing similar. Then use the tcp/ip vi´s from labview to build the http protocol. For more information about that here are some links with the documentation of http: http://tools.ietf.org/html/rfc1945 and http://tools.ietf.org/html/rfc2616.

Mike

[harrison1261]

Hey Mike thanks for all the help we are slowly struggling along. I was wondering if maybe you could test out our control panel by turning it on online. the web adress is http://photpower.com. Let me know if you think you might be able to do this, and if so how your VI was set up

Jose Castellano

Tom Harrison

Maria Svenstrom

[Karunya_R]

Hi Tom,

The answers posted on this dicussion forum  should get you started. You can also see if remote front panels can be used for your application. I tried to look up your control panel but the link seemed broken.

[Karunya_R]

Hi Tom,

Just a few questions so that I can provide a good solution. Are you trying to control the Power Manager remotely? Are you just trying to communicate to your manager using http/tcp/ip? Here are a few links about using TCP/IP communication:
Command Based Communication
Simple TCP/IP Messaging

There are also a bunch of examples in LabVIEW that use TCP/IP.

[Matthew_Kelton]

The data sheet seem makes one reference to telnet.  Can you telnet into this device?  If so, this would be much easier to implement than HTTP.