owiButtonWriteData (Function)

owiButtonWriteData will write a block of data to a memory iButton for later to be read by owiButtonReadData.

Before a write can be done, an owiButtonGetID must be completed.

When a write request is executed, the index and data size is verified against the following possible values:

If the iButton found by owiButtonGetID is not present at the time of writing, an "iButton not present" (-2) will be returned.

Input:

index : INT(1..Max)

Location number the data should be stored in.

data : ADR

Address of the memory block that holds the data to be stored.

size : INT(0..Max)

Maximum number of bytes to store from "ptr".

Returns: INT

Declaration:

FUNCTION owiButtonWriteData : INT;
VAR_INPUT
   index    : INT;
   data     : PTR;
   size     : INT;
END_VAR;

Example:

INCLUDE rtcu.inc
 
PROGRAM example;
VAR
   id    : STRING;
   data  : ARRAY[1..29] OF SINT;
   rc    : INT;
   str   : STRING;
   i     : INT;
END_VAR;
BEGIN
   // Retrieve ID of I-Button
   id := owiButtonGetID();
 
   // iButton detected.
   IF strLen(str := id) <> 0 THEN
      // clear data area
      FOR i := 1 TO SIZEOF(data) DO
         data[i] := 0;
      END_FOR;
      
      str := strFormat(format := "ID: " + id);
      // Copy contents of a string to memory
      strToMemory(dst := ADDR(data), str := str, len := strLen(str := str));
      
      rc := owiButtonWriteData(index := 1, data := ADDR(data), size := SIZEOF(data));
      IF rc <> 0 THEN
         // Write a string to the debug window
         DebugFmt(message := "Write to iButton failed error code \1", v1 := rc);
      ELSE
         DebugMsg(message := "Data written to index 1 on " + id);
         DebugMsg(message := "Content : " + str);
      END_IF;
   END_IF;
END;
 
END_PROGRAM;