dll C structure

[maincool]

I search all the examples about how to pass the c  structure dll in LABView, but I really don't know the true answer.here is my question:

I want to use this dll which was given from my  customer.but I don't get the following data that I expected.

/*struct SDownloadInfo {

 BYTE status; // status of the  process (Eeprom Dawnload Status)
 BYTE perc;  // percentage of the process (0 - 100)
 BYTE err;  // error code (see ERR_CODE)
 BYTE nRetry; // n. attempt (1 - 3)
};

SBIT100_API SDownloadInfo GetDownloadInfo(),

the sepc. say that if the downloadinfo  is 4, the process is complete, but because this involed the SDownloadinfo,

I use the dll like this

but there is no correct data display,

Thanks! need your  help.

[shoneill]

Hi maincool,

You can send a cluster with 4 U8 elements and set the type to "Adapt to source".

A struct is basically a cluster.

Byte = u8

Make sure also that you configure the correct calling convention (C or WinAPI).

Hope this helps

Shane.

[maincool]

but when I use the U8 type, the dll can't export the data.

However when I set the return type be numeric, the return data is 0~4,the following cluster data is wrong,only 0 be displayed.

[shoneill]

My last post was nearly a year ago.

Can you post an example of your problem?

Shane.

[maincool]

dll C structure

[maincool]

Yes ,our product has been made about one year, but sometimes the dll seems not be stability, so when I do the following action:

1.call the dll to write the eeprom file.

2.call the dll to check the eerprom file status,

I only get the status number 1~4,as i describe it before, but the struct other parameters I can't get ,all of them are "0",

the dll invoke file and setting file show  my configuration.

Thanks a lot for your help!

[shoneill]

Have you tried defining the data as a U32 and then splitting into 4 U8s after calling the DLL?

This should give you back all your data.

If you call a DLL and don't get all data back you are expecting, chances are large that you're generating a memory leak.

Try passing a single U32 and see what you get back.

Shane.

[maincool]

Thanks a lot !Shoneill
You are right,I get the correct action and display!
But the data don't need pass anything, only split the data which got (U32) then split 4 bytee(U8), before my I only use U8,the result I ignore others three parameter..