Rockwell Automation 1772-AF4,D17726.5.3 User Manual, AUX FUNCT PROM - Manual (Page 48)

Programming
Chapter 3
3Ć40
AF4 Power Function
The AF4 power function evaluates y+x and gives the result in terms of a base
number r and a power of 10, s, by which you multiply this base number to
obtain the power function value. The equation is:
y+x = r(10) +s
where:
y = input base = XXX.
x = input exponent = XX.X
r = result base = X.XX
s = resultant exponent = +XX. (The first digit is always zero)
A request for zero to the zero power will result in plus one.
How to Enter an AF4 Power Function
To program an AF4 power function perform the following steps:
1. Press [SHIFT][EAF] or [SHIFT][SCT] on the keyboard of your industrial
terminal. Figure 3.1 appears on the CRT.
2. Enter 33, the function number for an AF4 power function.
This entry identifies that the function entered is to perform an AF4 power
function calculation and that the processor use the data table format shown in
Figure 3.39 when executed. The data address is reserved for the three digits of
the base number y. Digits 1 and 3 are the most significant digit (MSD) and least
significant digit (LSD) respectively. The implied decimal point is after the
LSD. The three digits in the next higher address are reserved for the exponent,
x, with an implied decimal point after digit 2. The three digits of the result
address are reserved for the result base, r, with the decimal point after the MSD.
The next higher address is reserved for the resultant exponent s. Digit one of
the exponent s is always zero; the implied decimal point is after digit 3.