Rockwell Automation 1772-AF4,D17726.5.3 User Manual, AUX FUNCT PROM - Manual (Page 40)

Programming
Chapter 3
3Ć32
Figure 3.26
Transfer of Sign Bit
200
G
200
15
201
PUT
201
PUT
16
Execute Aux
Function
Function Number:
Data Addr:
Result Addr: 14
201
AF4 Log to Base 10 Function
The AF4 log to the base 10 function finds the log of a 3-digit BCD integer. The
result is a 6-digit BCD number with an implied decimal point after the most
significant digit.
log (xxx.) - x.xx xxx
How to Enter an AF4 Log to Base 10 Function
To program an AF4 log to base 10 function perform the following steps:
1. Press [SHIFT][EAF] or [SHIFT][SCT] on the keyboard of your industrial
terminal. Figure 3.1 appears in the CRT.
2. Enter 30, the function number for an AF4 log to base 10 function.
This entry identifies that the function entered is to perform an AF4 log to base
10 calculation and that the processor use the data table format shown in
Figure 3.27 when executed. The three digits of the number whose log you want
are represented in BCD by the digits labeled 1 through 3 in the operand. The
6-digit result is represented by digits labeled 1 through 6. The most significant
digit (MSD) and least significant digit (LSD) are labeled.