Cutler-Hammer D50 - Shr Dshr

98 D50 PLC User's Manual
Instruction
Mnemonic Shift to Right Range
 Bit
■ Byte
SHR
DSHR
Shift to right (low-order bit) by N
bits
The highest bit becomes 0
■ Word
Ladder
D = Register address
N = Number of bits to rotate
Description
1. Order:
 Shift N bits to the right (from high-order bit to low-order bit).
 MSB (most significant bit) becomes 0.
 Fill the carry bit (F1.8) with the LSB (least significant bit).
2. Shift the register specified as D to the right by N bits. Each bit will move one bit position
lower in the register.
3. The D register is either a byte or a word. For SHR (byte), N = 0 to 7. For DSHR (word), N =
0 to 15.
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.
Example
Program Expression Time Chart
 Regardless of N, the MSB moves to the carry (F1.8)
and the LSB always becomes 0.
 The R0.0 input is the initial condition, used to set the
initial value of M0 to $FFFF.
SHR
D =
N =
R
MSB LSB
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 C carry
(F1.8)
p o n m l k j i h g f e d c b a
R0.0
R
DLET
D = M0
S = $FFFF
DSHR
D = M0
N = 1
R0.1
R
0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1
0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
R0.0
R0.1
$FFFF $7FFF $3FFF
M0
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com