Using DT in C function

[Igi]

Hello,
I'm trying to read values from a data table within a C function. I cannot find any examples.

Could you show some examples?

[s.pratt]

Hello,

 

I don't believe you can address the data table directly in the C function.  You would have to perform a 'read row from DTI' to put the row information into a tag.  Then pass this tag (which will be a struct) into your C function.

 

It is important to note that when passing the struct into a subroutine, the struct will update with each scan since it is a passed in by reference.  You will not have to pass the struct back out - it will be updated as it moves through the subroutine.

 

Hope this helps.

[Igi]

Hello,

 

I don't believe you can address the data table directly in the C function.  You would have to perform a 'read row from DTI' to put the row information into a tag.  Then pass this tag (which will be a struct) into your C function.

 

It is important to note that when passing the struct into a subroutine, the struct will update with each scan since it is a passed in by reference.  You will not have to pass the struct back out - it will be updated as it moves through the subroutine.

 

Hope this helps.

Thank you, but it is possible to use directly DT, but in last version of Unistream you can choose type of input DT then in C code is automatically generated this structure:

typedef struct

{

  unsigned int BufferPointer; // BufferPointer

  unsigned int EntrySize; // EntrySize

  unsigned int Number_of_rows; // Number of rows

  unsigned int Signature; // Signature

  char Status; // Status

  char PadUInt[3]; // PadUInt

} Data_Table_Indexed; // Data Table: Indexed

but I do not know what to do with these members of the structure( I know C programming very well and I can work with structures etc.) . I mean how to get data from that. I tried to read from all, I tried to write one of them then read from the others etc...,  but I have got just garbage values...

[s.pratt]

Thank you, but it is possible to use directly DT, but in last version of Unistream you can choose type of input DT then in C code is automatically generated this structure:

typedef struct

{

  unsigned int BufferPointer; // BufferPointer

  unsigned int EntrySize; // EntrySize

  unsigned int Number_of_rows; // Number of rows

  unsigned int Signature; // Signature

  char Status; // Status

  char PadUInt[3]; // PadUInt

} Data_Table_Indexed; // Data Table: Indexed

but I do not know what to do with these members of the structure( I know C programming very well and I can work with structures etc.) . I mean how to get data from that. I tried to read from all, I tried to write one of them then read from the others etc...,  but I have got just garbage values...

Please e-mail into support@unitronics.com for more information on this topic.

 

As far as I am aware, this type of input for a C function is only to configure a data table.  But I do not believe it will allow you to read/write from a specific data table.