Rockwell Automation 1747-PT1, D1747NP002 Hand-Held Terminal - Manual (Page 304)

Chapter 21
Move and Logical Instructions
21–4
Entering Parameters
•
Source – the address of the data you want to move.
•
Mask – the address of the mask word through which the instruction
moves data. You can also enter a hex value (constant). Refer to appendix
B for more information regarding masks and hexadecimal numbering.
•
Destination – the address where the instruction moves the data.
Using Arithmetic Status Bits
C always reset
V always reset
Z set if the result is zero; otherwise reset
S set if the result is negative; otherwise reset
Operation
When the rung containing this instruction is true, data at the source address
passes through the mask to the destination address.
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
B3:2 before move
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
source B3:0
1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0
Mask F0F0
0 1 0 1 1 1 1 1 0 1 0 1 1 1 1 1
B3:2 after move
MVM
MASKED MOVE
Source
B3:0
0101010101010101
Mask F0F0
Dest B3:2
1111111111111111
unaltered unaltered
Mask (do not pass) data by resetting bits in the mask; pass data by setting
bits in the mask. The instruction does not operate unless you set mask bits to
pass data you want to use. The bits of the mask can be fixed by a constant
value, or you can vary them by assigning the mask a direct address. Bits in
the destination that correspond to 0s in the mask are not altered.