User Manual, AUX FUNCT PROM Manual

Programming
Chapter 3
339
4. Enter the operand.
You can enter the operand from the keyboard of your industrial terminal or
through ladder diagram functions. Entry of an operand (exponent) of e) of 9.42
yields an exponential function value of 1.23(10)
004
. The base r resides in word
305 and the exponent of ten resides in word 306 as shown in Figure 3.37.
Figure 3.37
AF4 Exponential Function Format After Execution
171615141312111076543210Bit No.
Data Address
Operand
Result AddressResult Base r
DE
E = Enable Bit (1 = Function in Progress)
D = Done Bit (1 = Function Complete)
11506
S = Sign Bit (1 = Negative)
S
S
s (Power of 10)
200
305
306
(0)
(0) (1)
(0)
942
123
004
Entry and Display of Input and Result Values
Figure 3.38 shows one method for inserting input values and displaying input
values and results of an AF4 exponential function. Although there are several
techniques for accomplishing this, we chose get instructions. The first rung
requests execution of an AF4 exponential function. The second rung contains
9.42, the exponent of e in word 200 with an implied decimal point after the first
digit. It also shows the result, (1.23)(10)
004
, in the form of 123 in word 305 and
004 in word 206. The decimal points are implied.
Figure 3.38
AF4
Exponential Function Input and Result Display Rungs
201
648
G
305
647
G
306
389
G
Bit
Storage
Execute Aux
Function
Function Number:
Data Addr:
Result Addr: 305
32