Operator: SHL

The IEC operator is used for bitwise shift of an operand to the left.

‎erg := SHL (in, n)‎

‎in‎: Operand which is shifted to the left

‎n‎: Number of bits to shift ‎in‎ to the left

NOTICE

If ‎n‎ exceeds the data type width, then it depends on the target system how the ‎BYTE‎, ‎WORD‎, ‎DWORD‎, and ‎LWORD‎ operands are padded. The target systems cause padding with zeros or ‎n MOD <register size>‎.

NOTICE

Note the number of bits which CODESYS uses for this operation as defined by the data type of the input variable ‎in‎.

Examples

The results for ‎erg_byte‎ and ‎erg_word‎ are different, although the values of the ‎in_byte‎ and ‎in_word‎ input variables are the same and the data types of the input variables are different.

PROGRAM shl_st
VAR
  in_byte : BYTE := 16#45; (* 2#01000101 )
  in_word : WORD := 16#0045; (* 2#0000000001000101 )
  erg_byte : BYTE;
  erg_word : WORD;
  n: BYTE := 2;
END_VAR

erg_byte := SHL(in_byte,n); (* Result is 16#14, 2#00010100 *)
erg_word := SHL(in_word,n); (* Result is 16#0114, 2#0000000100010100 *)

FBD