BufDec [ezeio documentation]

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Decode a part of a buffer into a scalar

Description

BufDec( const buf[], offset, method )

This command will decode a portion of a buffer into a scalar variable.

Parameters

`buf`	Data buffer
`offset`	Byte offset into the buffer where to start the decoding
`method`	What type of value is encoded in the buffer

Available methods:

Method	Length	Type	Description
BT_INT8	8 bit	signed integer	Single octet value
BT_UINT8	8 bit	unsigned integer	Single octet value
BT_INT16	16 bit	signed integer	Big endian integer
BT_UINT16	16 bit	unsigned integer	Big endian integer
BT_INT32	32 bit	signed integer	Big endian integer
BT_UINT32	32 bit	unsigned integer	Big endian integer
BT_INT32LE	32 bit	signed integer	Little endian integer
BT_UINT32LE	32 bit	unsigned integer	Little endian integer
BT_FLOAT	32 bit	float	IEEE 732 floating point

Also available for decoding bitmaps:

Bit offset : BT_BITOFS0 through BT_BITOFS15
Bit mask : BT_BITMASK1 through BT_BITMASK8

The BT_BITOFSx and BT_BITMASKx methods can be OR:ed together for bitmask decoding.

Example: To extract a 3 bit value from bit position 5,6 and 7, use BT_BITOFS5 | BT_BITMASK3

Return value

Returns the decoded value

Example usage

    new x;
    new s{10};
 
    if(ModbusRead(5, MB_HOLDING, 100, 2, s) == 4) {  // Request and receive two registers (32 bits total)
        x = BufDec(s, 0, BT_INT32);                  // Decode the received data as a 32 bit integer
        // ..further processing        
    }