Promotic

GetBuffer - method of the PmBuffer object

Description:
Reading the data block in the form of the PmBuffer object.
Syntax:
Object GetBuffer([Long nOffset], [Long nSize])
Parameters:
nOffset[optional] (Long) Specifies the position of read value in the data block.
The read value must be inside the data block. The item is read either whole or not read at all.
Default: 0.
>= 0 - Index (in bytes, zero-based index) in the data block.
-4 - The internal automatic position is used (see the AutoOffset property). It points behind the last read or written value.
This operation shifts the internal automatic position behind the read/written value.
If the items are read/written one by one then it is not necessary to define the position manually, but it is better to use this automated positioning.
nSize[optional] (Long) The size of read data block.
The -1 value (default) means that the data block is read from the defined starting position to the end.
Return value:
The method returns new PmBuffer object containing the read data block.
Note:
This method is also functional in Web panels.
See also:
Example:
JavaScriptSelect and copy to clipboard

var oBuf = Pm.CreatePmBuffer();
var s1 = "40302010605070";
oBuf.SetHexaString(-2, s1);

var oBuf2 = oBuf.GetBuffer(5, -1);
var val = oBuf2.GetHexaString(-4);   // val = 5070

History:
Pm9.00.04: Created
PROMOTIC 9.0.27 SCADA system documentation MICROSYS, spol. s r.o.

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