F126_DROL

The function rotates the value at output d to the left. The number of bits at output d to be rotated to the left is specified by the value assigned at input n. This shift can lie between 0 and 255 (only the lower value byte of n is effective).Left rotate means that the bits shifted out of bit position 31 (MSB) are shifted via bit position 0 (LSB) into the value at output d.

Parameters

Input

n (INT)

Number of bits to be rotated (range: 0 to 255)

Output

d (DWORD, DINT, UDINT, DATE, TOD, DT)

32-bit area

Remarks

• When input n = 0, no rotation takes place.

• When at input n > 32, the same result is achieved as with a number n < 32: e.g. n = 33 produces the same result as when n = 0; n = 34 the same as n = 1.

• The bit at position 32 - n (the last bit shifted out to the right) is simultaneously stored in the system variable sys_bIsCarry (carry flag) so that it can be evaluated accordingly.

Error flags

sys_bIsCarry (turns to TRUE for one scan)

if the bit at position 32 - n of d has the value 1.