BCD_TO_INT / INT_TO_BCD

Convert between Binary-Coded Decimal (BCD) encoded bit strings and integer values.

Signature

BCD_TO_INT:

    ┌─────────────┐
IN ─┤  BCD_TO_INT ├─ OUT
    └─────────────┘

FUNCTION BCD_TO_INT : ANY_INT
  VAR_INPUT
    IN : ANY_BIT;
  END_VAR
END_FUNCTION

BCD_TO_INT accepts BYTE, WORD, DWORD, LWORD for IN; the return type is the corresponding unsigned integer (USINT, UINT, UDINT, ULINT).

INT_TO_BCD:

    ┌─────────────┐
IN ─┤  INT_TO_BCD ├─ OUT
    └─────────────┘

FUNCTION INT_TO_BCD : ANY_BIT
  VAR_INPUT
    IN : ANY_INT;
  END_VAR
END_FUNCTION

INT_TO_BCD accepts USINT, UINT, UDINT, ULINT for IN; the return type is the corresponding bit string (BYTE, WORD, DWORD, LWORD).

Inputs (BCD_TO_INT)

Name

Type

Description

IN

ANY_BIT

The BCD-encoded bit string to decode.

Outputs (BCD_TO_INT)

Name

Type

Description

Return value

ANY_INT

The decoded integer value. Type is the unsigned integer corresponding to the width of IN.

Inputs (INT_TO_BCD)

Name

Type

Description

IN

ANY_INT

The unsigned integer value to encode.

Outputs (INT_TO_BCD)

Name

Type

Description

Return value

ANY_BIT

The BCD-encoded bit string. Type is the bit string corresponding to the width of IN.

Description

BCD (Binary-Coded Decimal) encodes each decimal digit in a 4-bit nibble. For example, the decimal value 42 is encoded as 0100_0010 in BCD (4 in the high nibble, 2 in the low nibble).

BCD_TO_INT decodes a BCD-encoded bit string into its integer value. The function treats invalid BCD nibbles (values 10–15) as 0.

INT_TO_BCD encodes an integer value into BCD format. Values that exceed the maximum representable BCD value for the target width wrap around.

Maximum values per width:

  • BYTE: 99

  • WORD: 9999

  • DWORD: 99999999

  • LWORD: 9999999999999999

Example

int_val := BCD_TO_INT(BYTE#16#42);  (* int_val = 42 *)
bcd_val := INT_TO_BCD(USINT#42);    (* bcd_val = 16#42 *)

See Also

References