What's the function for VISA WRITE in CVI?

[dragondriver]

Hi all,

  I am porting the labview vi to CVI. I have an external device which is connecting to the computer with GPIB and in the labview, I use VISA WRITE (the icon contains VISA abc) to send the command to control the external device. In the CVI, I didn't find any example about VISA, so what command should be used to replace VISA abc WRITE in labview vi code? How do I specified the device address? I appreciate it if there is any example for reference.

[Wolfgang]

In CVI, you will find the VISA commands via the menu Library / VISA (provided you have VISA installed). A brief introduction can be found here

The first command probably will be to open the resource manager

status = viOpenDefaultRM ( &resource_manager_handle )

then to open the port

status = viOpen ( resource_manager_handle, port_descriptor, VI_EXCLUSIVE_LOCK, timeoutvalue, &session_handle );

A typical write command looks like

status = viWrite ( session_handle, buffer, count, return_count )

Hope this will help getting you started.

[dragondriver]

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@Wolfgang wrote:

In CVI, you will find the VISA commands via the menu Library / VISA (provided you have VISA installed). A brief introduction can be found here

The first command probably will be to open the resource manager

status = viOpenDefaultRM ( &resource_manager_handle )

then to open the port

status = viOpen ( resource_manager_handle, port_descriptor, VI_EXCLUSIVE_LOCK, timeoutvalue, &session_handle );

A typical write command looks like

status = viWrite ( session_handle, buffer, count, return_count )

Hope this will help getting you started.

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Thanks. But I don't know how to create the resource_manager_handle, is there any example to show how to use that? In the labview code, I only have to specify the address like GBIP0:xxx:yyyy 😞

[Wolfgang]

You create the resource_manager_handle the way I told you, by calling  viOpenDefaultRM ( &resource_manager_handle )

If you are looking for explanations and examples, the help manual may be useful, too.

[dragondriver]

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@Wolfgang wrote:

You create the resource_manager_handle the way I told you, by calling  viOpenDefaultRM ( &resource_manager_handle )

If you are looking for explanations and examples, the help manual may be useful, too.

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oh, so you mean &resource_manager_handle is the handle returned by viOpenDefaultRM? I thought I have to create that first and pass that to the function. Sorry, I didn't understand the meaning of '&' before I read this reply. I just google it 😉

[Wolfgang]

Well, CVI is an integrated environment of libraries, editor, etc. but the C in CVI means that it is based on the language C  

So instead of googling for the ampersand you may read a book about C... in the long term it will not work without it

One (of several) internet sites about C is http://www2.its.strath.ac.uk/courses/c/