Rockwell Automation 1761 MicroLogix 1000 Programmable Controllers - Manual (Page 143)

Using Math Instructions
8–11
Clear (CLR)
Use the CLR instruction to set the destination to zero. All of the bits reset.
Updates to Arithmetic Status Bits
With this Bit: The Controller:
S:0/0 Carry (C) always resets.
S:0/1 Overflow (V) always resets.
S:0/2 Zero (Z) always sets.
S:0/3 Sign (S) always resets.
Square Root (SQR)
When this instruction is evaluated as true, the square root of the absolute value of
the source is calculated and the rounded integer result is placed in the destination.
The instruction calculates the square root of a negative number without overflow or
faults. In applications where the source value may be negative, use a comparison
instruction to evaluate the source value to determine if the destination may be
invalid.
Updates to Arithmetic Status Bits
With this Bit: The Controller:
S:0/0 Carry (C) sets if the source is negative; otherwise cleared.
S:0/1 Overflow (V) always resets.
S:0/2 Zero (Z) sets when destination value is zero.
S:0/3 Sign (S) always resets.
Programming
Execution Times
(
µ
sec) when:
True False
20.80 4.25
CLR
CLEAR
Dest
Execution Times
(
µ
sec) when:
True False
71.25 6.78
SQR
SQUARE ROOT
Source
Dest