Watlow LogicPro - Manual (Page 172)

Chapter 10: Function Blocks LogicPro User’s Guide
156 Watlow Anafaze Doc.# 28002-00 Rev 3.00
a constant or assigned a Variable name, which allows their
value to change dynamically within the program.
Figure 10.36 Square Root Function Block
Inputs
EN is the Square Root enable bit. A True condition of this bit
causes the square root of RIN to be placed in ROUT . In a
program using Ladder logic, the value of EN is determined by
the Boolean evaluation of elements placed between the left
power rail and
EN . In FBD programs, the value of EN
determined by the Variable connected to EN . If no contacts are
placed on the rung before EN in a Ladder Diagram program,
the value of EN is always True. In FBD, all inputs must be
connected to a Variable.
RIN is the Square Root input Variable. The range of values this
Variable can assume is from -3.4x10 38 to 3.4x10 38 . If this
Variable is assigned a value out of this range, unpredictable
results will occur.
Outputs
Q is the Square Root output bit. This bit is enabled and passes
power when the enable bit is True. Place an output coil on the
rung between Q in the function block and the right power rail
(in a Ladder Diagram program) or connect an output Variable
to it (in a FBD program).
ROUT is the Square Root output Variable. This value is set
equal to the square root of the input Variable when the enable
bit is True. The range of values this Variable can assume is
from -3.4x10
38
to 3.4x10
38
. If this Variable is assigned a value
out of this range, unpredictable results will occur. ROUT
retains its last valid value whenever EN is disabled.