Watlow LogicPro - Manual (Page 168)

Chapter 10: Function Blocks LogicPro User’s Guide
152 Watlow Anafaze Doc.# 28002-00 Rev 3.00
RC is the product value. RC contains the product of RA and RB
as long as 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 these ranges, ENO is
disabled. RC reverts to its last valid value whenever ENO is
disabled.
Real Divide (RDIV)
The Real Divide (RDIV) function block, shown in Figure
10.32, produces the quotient of two real Variable values.
RDIV calculates the quotient between one value (RA) which is
the dividend and another value (RB) which is the divisor and
places the result in another Variable (RC) when the enable bit
(EN) is True. The values of RA and RB can be preset to a
constant or assigned a Variable name, which allows their
value to change dynamically within the program.
Figure 10.32 Real Divide Function Block
Inputs
EN is the Real Divide enable bit. A True condition of this bit
causes the value of RA to be divided by the value of RB and the
result stored in RC. 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 the function
block. In FBD programs, the value of EN is 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.
RA is the dividend. 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 these ranges, unpredictable results will
occur.
RB is the divisor. 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 these ranges, unpredictable results will occur.
Also, if RB is assigned a value of zero (0), the enable out bit
becomes False and RC retains its previous value.