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• IEC 61131-3 Functions and Function Blocks
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• ROL

ROL

Type	Function
Description	Performs a bitwise left rotation on the operand connected to the input IN. N specifies the number of bits to be rotated.
Notes	Overloaded function. The function can operate on various input data types. When rotating with N < 0, the function delivers the output value 0 because the parameter N is always considered as an unsigned integer value.
Parameters	Inputs IN Data type: ANY_BIT Description: Input value. N Data type: ANY_INT Description: Number of bits to be rotated. Output OUT Data type: ANY_BIT Description: Output value.
Error behavior	Error behavior The following table shows the errors which may occur while executing the function and the value returned by the function in the corresponding error case. Error case Output value N < 0 0
Example	Bitwise left rotation of 3 bits
Additional information	EN/ENO behavior The POU is only executed if TRUE is applied to the EN input. If EN = FALSE, the POU is not executed and ENO = FALSE indicates the inactivity. If any of the errors listed under "Error behavior" occurs while executing the function, ENO is set to FALSE. Further Info See the topic "General information on execution control with EN/ENO" for further details.