Rockwell Automation 2707-NP DTAM Programming Software - Manual (Page 175)

Appendix D
Data Formats
D–5
32 Bit Floating Point (PLC Controllers Only)
Floating Point
(Two Consecutive 16 Bit addresses)
Range = ± 1.2E-38 to ± 3.4E +38
Bit
32
Exponent Mantissa
Bit
24
Bit
23
Bit
1
Bit
31
This data format displays data located in two consecutive 16 bit addresses as
a 32 bit floating point value. Floating points use a memory register plus the
next higher register to form the 32 bit address. The range for the floating
point value is +1.175495E
-38 to +3.402823E +38 .
Note: The floating point format adheres to the ANSI/IEEE 754 standard.
This data format may be scaled to different engineering units.
The DTAM Micro Operator Interface Module now supports floating point
numeric entry and display.
Floating point display is controlled by the value of the Decimal Opt
parameter. The value can be either 0 or 1. If Decimal Opt=0 , the display
width is set to 10 characters (including the decimal point), and the decimal
point can float anywhere within that width. If
Decimal Opt=1 , then you
have the option of setting the display from 2 to 8 characters wide (including
decimal), and the decimal point will always appear at a fixed position you
select.
The module can display floating point numbers up to 8 characters long (7
digits plus decimal point). However, you can enter numbers up to 13 digits
long. Any time you enter a number between 7 and 13 digits long it will be
stored internally as an exponential value. For example:
Table 1
How the DTAM Micro stores input
Entered Number Number Stored Internally
1234567 1234567
12345678 1.234568E+07*
–1234567 –1234567
1234567890123 1.234568E+12*
* Note rounding
The module’s firmware will not display numbers in exponential form. Nor
will it allow you to enter numbers longer than 13 digits.
DTAM Micro
Floating Point Numbers