Rockwell Automation 1771-DB Basic Module User Manual - Series A - Manual (Page 55)

Operating Functions
Chapter 5
5–18
Mode: RUN
Type: Assignment
DATA
DATA specifies expressions that you can retrieve using a READ statement.
If multiple expressions per line are used, you MUST separate them with a
comma.
Example:
u10 DATA 10,ASC(A), ASC(B), 35.627
Important: You cannot
use the CHR() operator in a DATA statement.
READ
READ retrieves the expressions
that are specified in the DATA statement
and assigns
the value of the expression to the variable in the READ
statement.
The READ statement is always followed by one or more
variables. If more than one variable
follows a READ statement, they
are separated by a comma.
RESTORE
RESTORE “resets”
the internal read pointer to the beginning of the
data so that it may be read again.
Example:
u10 FOR I=1 TO 3
u20 READ A,B
u30 PRINT A,B
u40 NEXT I
u50 RESTORE
u60 READ A,B
u70 PRINT A,B
u80 DATA 10,20, 10/2,20/2,SIN(PI),COS(PI)
uRUN
10 20
5 10
0 –1
10 20
Every time
a READ statement is encountered the next consecutive
expression
in the DATA statement is evaluated and assigned to the
variable in the READ statement.
You can place DATA statements
anywhere within a program.
They are not executed and do not cause an
error. DATA statements are considered to be chained
together and appear
to be one large DATA statement. If at anytime all the data is read and
another READ statement is executed,
the program terminates and the
message ERROR: NO
DATA – IN LINE XX prints to the console
device.
5.4.6
Statements: DATA –
READ – RESTORE