Rockwell Automation 1761 MicroLogix 1000 Programmable Controllers - Manual (Page 161)

Using Data Handling Instructions
9–13
Move and Logical Instructions Overview
The following general information applies to move and logical instructions.
Entering Parameters
•
Source is the address of the value on which the logical or move operation is to
be performed. It can be a word address or a constant. If the instruction has two
source operands, it will not accept constants in both operands.
•
Destination is the address where the resulting data is stored. It must be a word
address.
Using Indexed Word Addresses
You have the option of using indexed word addresses for instruction parameters
specifying word addresses. Indexed addressing is discussed in chapter 4.
Updates to Arithmetic Status Bits
The arithmetic status bits are found in Word 0, bits 0–3 in the controller status file.
After an instruction is executed, the arithmetic status bits in the status file are
updated:
Bit Name Description
S:0/0 Carry (C) Set if a carry is generated; otherwise cleared.
S:0/1 Overflow (V)
Indicates that the actual result of a math instruction
does not fit in the designated destination.
S:0/2 Zero (Z)
Indicates a 0 value after a math, move, or logic
instruction.
S:0/3 Sign (S)
Indicates a negative (less than 0) value after a
math, move, or logic instruction.
Programming