Rockwell Automation 57C610 Enhanced Basic Language, AutoMax - Manual (Page 23)

4Ć3
4.1.1.2 Double Integer Variables (Long Integers)
A double integer variable is a named location in which an integer
value can be stored. It is called a double" integer because it
requires two 16Ćbit words, or 32 bits, to represent its value in the
range +2147483647 to -2147483648 (a 32Ćbit signed number). It is
named using the rules listed in section 4.1.1 and terminated with an
exclamation point (!). If you include an integer variable in a program,
its value can be an integer (no fractional part) or a real (decimal)
number. If you assign a decimal number to a double integer
variable, the fractional part will be truncated or ignored. For
example, if the statement attempts A! = 3.6574, the value 3 will be
assigned to A!.
If an attempt is made to assign a value larger than the range
-214783648 to +214783647 to a double integer variable, BASIC will
log this condition into the error log and will load the largest possible
double integer value into the variable. For example, if the statement
attempts A! = +2157483647, BASIC will log this as an error and set
a A! = +2147483647; if the statement attempts A! = -214783649,
Basic will log an error and A! will be set to = -214783648.
The following are valid double integer variables:
RESOLVER_ADDRESS!
LARGE_COUNTER!
FOREIGN_CARD_ADR!
All internal integer calculations are in double precision, or 32 bits.
4.1.1.3 Real Variables
A real variable is a named location in which a decimal value can be
stored. It is named using the rules listed in section 4.1.1. Unlike the
other variable data types, a real variable has no terminating
character, such as % or !.
A real variable can have the following values:
9.2233717 x 10
18 > positive value > 5.4210107 x 10 -20
-9.2233717 x 10 18 > negative value > -2.7105054 x 10 -20
Note: When entering real variable values in your program, use
scientific notation. See section 4.2.3 for more information on real
constant formats.
The following are examples of valid real variables:
ROLL_RATIO
GAIN_ADJUST
WINDUP_FRACTION
Only eight digits of significance are used when entering a real
number, thus 9.4481365 and 9.4481365200178 would be treated the
same way. The 200178 at the end of the second number would be
ignored. Real or decimal numbers require more time to process
while BASIC is running due to the increased accuracy and additional
internal calculations required.
It is legal to assign an integer to a real variable (REAL=45).
However, if the integer is greater than 2 24 (16777216), the real
value into which it is converted will be imprecise because of the
format in which the real numbers are manipulated (24Ćbit mantissa).