Cutler-Hammer D320 PLC, User Manual

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118
D320 PLC User's Manual
Instruction
Mnemonic Rotate to the Left Range
Bit
■ Word
ROL
DROL Rotate the specified address to
the left with the carry flag
■
Double words
Ladder
D = Register address
N = Number of bits to rotate
Description
1. Order:
Shift N bits to the left (from low-order bit to high-order bit) including the carry bit.
The MSB (most significant bit) moves to the carry bit (F1.8).
Input F1.8 (carry bit) in the LSB (least significant bit).
2. This instruction is different from the RLC instruction because it sends the MSB to the carry
bit and the carry bit moves to the LSB. The input to the LSB can be changed by setting or
clearing the carry bit.
3. The D register is either a word or a double word. For ROL (word), N = 0 to 15. For DROL
(double word), N = 0 to 31.
4. This operation will occur on every scan for which the input condition is true (On). To perform
the operation only on a change of input condition, use the rising/falling edge contact.
ROL
D =
N =
R
MSB
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
LSB
carry
(F1.8)
C p o n m l k j i h g f e d c b a
C