"Looking for a VI that can function w/ C commands? The VI is

[Read text]

to communicate with equipment via SR232 port." "I am new to Labview user, so please bare with me.

I am working with a Davis Weather station and are trying to communicate with it via
RS-232 port. The vendor's command set is in "C." My dilema is to find an already
existing VI that can extract the information using C commands and place the
information in a format from which I can create a graph.

Since I know, no one VI will do this I would appreciate any suggestions.

Regards
Sal

[Friar]

I do not think that you will find a driver to do what you need to do specifically but it would not be too hard to build one. I am not sure what you mean by "The vendor's command set is in "C"". It may mean that all you need to do with LabVIEW is send RS-232 commands or you may need to access the code with dlls. Do you have the source code or at least the prototypes? How do you communicate with the system now?

[Read text]

Hello Friar

Thank you, first for taking the time to answer my post. As you can see I am very new to the medium.

I contacted a Labview representative and he address the commands to communicate with the equipment (via RS-232) as the "Command Set."

I also contacted the equipment manufacturer for these so called "Command Set" of instructions and theydirected me to the following:

WeatherLink Serial Communications Reference 3.3
Allows programmers to create their own applications using our weather instruments and WeatherLink data logger. Describes the communications protocol between the WeatherLink and computer. Binaries and sample source code written in C+ and Visual Basic is included. This reference is designed for users who are not operating under a 32
-bit platform and are unable to utilize the DLL (Dynamic Link Libraries) described above.
Operating System: DOS, Unix, OS/2, etc. documents

I am currently communicating with the equipment using their software. But the software will not download information automatically at the time intervals prerequisites needed.

Regards
Sal

[abrause]

You need to download "WeatherLink Dll 1.03" from the Davis website.
This DLL contains all the functions to talk to your instrument via
the "Call Library Function" in LabVIEW.

After you install the Weatherlink DLL on your computer, open a
Call Library Function node, right click on it and enter the path
to the Weatherlink DLL. Once you do this, all the functions
from the DLL will appear listed in Function Name. There are a bunch
of them.

Now you can call these functions from LabVIEW in the app you
are going to write. Probably best to study up a bit on how the
Call Library Function works before you start.

Have fun!

Alan



"Read text" wrote in message news:506500000008000000221D0000-986697009000@quiq.com...
> "Looking for a VI that can function w/ C command
s? The VI is
> to communicate with equipment via SR232 port."
>
> "I am new to Labview user, so please bare with me.
>
> I am working with a Davis Weather station and are trying to
> communicate with it via
> RS-232 port. The vendor's command set is in "C." My dilema is
> to find an already
> existing VI that can extract the information using C commands
> and place the
> information in a format from which I can create a graph.
>
> Since I know, no one VI will do this I would appreciate any
> suggestions.
>
> Regards
> Sal

[Read text]

Alan,

Thank you.

This if very helpful I will get started getting knee deep into the "Call Library Function."

Regards
sal

[solarlab]

Hi Sal,

I'm in the same sort of boat you seemed to be in a few years ago. I'm trying to interface a Davis Weather Wizard 3 with LabView. I've tried to directly communicate with the device via the serial port, but unfortunately don't have the command set. The set I do have is the same ones you've mentioned that are written in C. I also tracked down the .dll file and attempted to use the call function node. I'm not sure how to use it properly however, and cannot find what input parameters to use in order to get an output. Any help at all would be great. I'm looking specifically to get the wind speed and direction from the device. If you have any sample programs that would be greatly appreciated.

Thanks!

Ayon

[smercurio_fc]

It's highly unlikely that sal is monitoring this thread anymore, given that his last login was in 2001. Given that, if you have the C code you should be able to see the serial commands in there. Alternatively, you can use a serial port sniffer program to see what commands are being sent when you use their software. The vendor should be able to provide you with the API documentation for the DLL. Have you tried to contact them?