Rockwell Automation 1747-PT1, D1747NP002 Hand-Held Terminal - Manual (Page 316)

Instructions
Chapter 23
Bit Shift, FIFO, and LIFO
23–4
Operation – Bit Shift Left
When the rung goes from false–to–true, the enable bit (EN bit 15) is set and
the data block is shifted to the left (to a higher bit number) one bit position.
The specified bit at the Bit Address (source) is shifted into the first bit
position. The last bit is shifted out of the array and stored in the unload bit
(UL bit 10) in the status byte of the control element. The shift is completed
in one scan.
For wraparound operation, set the Bit Address equal to the address of the last
bit of the array or to the UL bit, whichever applies.
The figure below illustrates how the Bit Shift Left instruction functions.
(EN)
(DN)
BSL
BIT SHIFT LEFT
File
#B3:1
Control R6:53
Bit Address I:22/12
Length 58 19 18 17 16
35 34 33
51 50 49 48
67 66 65 64
32
23 22 21 20
39 38 37
55 54 53 52
71 70 69 68
36
27 26 25 24
43 42 41
59 58 57 56
73 72
40
31 30 29 28
47 46 45
63 62 61 60
44
DO NOT USE
58
bit
array
#B3:1
Bit Address
(source) I:22/12
Unload Bit R6:53/10
Data block is shifted one bit at
a time from bit 16 to bit 73.
Operation – Bit Shift Right
When the rung goes from false–to–true, the enable bit (EN bit 15) is set and
the data block is shifted to the right (to a lower bit number) one bit position.
The specified bit at the Bit Address (source) is shifted into the last bit
position. The first bit is shifted out of the array and stored in the unload bit
(UL bit 10) in the status byte of the control element. The shift is completed
in one scan.
For wraparound operation, set the Bit Address equal to the address of the
first bit of the array or to the UL bit, whichever applies.
The figure below illustrates how the Bit Shift Right instruction functions.
(EN)
(DN)
BSR
BIT SHIFT RIGHT
File
#B3:2
Control R6:54
Bit Address I:23/06
Length 38
35 34 33
51 50 49 48
67 66 65 64
32 39 38 37
55 54 53 52
69 68
36 43 42 41
59 58 57 56
40 47 46 45
63 62 61 60
44
DO NOT USE
38
bit
array
#B3:2
Bit Address
(source) I:23/06
Unload Bit R6:54/10
Data block is shifted one bit at
a time from bit 69 to bit 32.