Rockwell Automation 57C610 Enhanced Basic Language, AutoMax - Manual (Page 46)

6Ć6
6.3 Variable Assignment
(LET/SET_MAGNITUDE)
There are two formats for assigning a value to a variable: the LET
statement and the SET_MAGNITUDE statement. TheLET" in an
assignment is optional. In actuality tasks are more readable without
LET" in front of the assignment. Its use is left to the discretion of the
programmer.
The following is the LET statement format:
LET variable = expression
where:
variable = simple (A%) or subscripted [A%(5)]; variable of
any data type.
expression = can be as simple as a constant or as involved
as a complex arithmetic expression. (See
section 5.0).
The following are valid LET statements:
10 LET SPEED%=25
15 LET MESSAGE$=SYSTEM FAILURE"
95 WINDER_EMPTY@=TRUE
25 GAIN_CHANGE!=GAIN%*13
10 A% = B% + C% - (D% / 234) + 15 -F%
22 TENSION = TENSION - ((19.7765 * &
GAIN%)/78 - 12.3) + OLD_REFERENCE
The following are invalid LET statements:
10 LET = ĂA% (no variable specified on the left side of the
Ăequal sign)
10 LET A%Ă= THIS IS A MESSAGE" (a string value cannot
be assigned to an integer variable)
10 LET A% = 6+22-(B%-34)+(missing term) (Invalid
expression)
The purpose of the SET_MAGNITUDE statement is to allow the
programmer to enter 16Ćbit hexadecimal values without having to
worry about sign extending the numbers into a 32Ćbit form. The
following is the SET_MAGNITUDE statement format:
SET_MAGNITUDE (variable, value)
where:
variable = a numeric simple variable (integer, double
integer) (not an array)
value = a numeric constant or expression of same type
as variable
If the variable specified in the statement is a single integer variable,
the value loaded will be only the lower 16Ćbits of the value field with
no sign extension:
10 SET_MAGNITUDE(A%,0FFFFH)
(A% is replaced by 0FFFFH)
10 SET_MAGNITUDE(A%,0C249H OR 1234H)
(A% is replaced by 0D23DH)