Rockwell Automation 57C610 Enhanced Basic Language, AutoMax - Manual (Page 62)

6Ć22
Tasks do not have to call the variables by the same names when
reading and writing to the channel; they simply write an integer
quantity (for an integer position in the template) and read an integer
quantity into an integer variable. Note that, just like the normal print
operation, the print list of items may contain any kind of expression,
which will be evaluated first and then printed. The number of items
and their data types used in a print or input to a channel must match
the OPEN CHANNEL definition; otherwise, an error will occur.
A CLOSE statement is not used with a channel because once it is
opened, it remains open. There is no provision to open and then
close channels.
6.7 Real Time Enhancements
BASIC provides two statements that allow specified sections of
tasks to be executed at a known time.
1. DELAY statement
2. START statement
6.7.1 DELAY Statement
The DELAY statement provides for a simple time delay in a task.
The following is the DELAY statement format:
DELAY n time_units
where:
n = any arithmetic expression or constant that evaluates to
an integer result
time_units = unit of time to be delayed
The possible time units for both the DELAY and the START
statement are TICKS, SECONDS, MINUTES, and HOURS. The tick
rate is userĆdefinable for each Processor being used. The range is
0.5 milliseconds to 10 milliseconds. The default tick rate is 5.5
milliseconds. The plural form of the time unit must always be used,
even when referring to one unit, e.g., DELAY 1 HOURS.
The following are valid DELAY statements:
30 DELAY 255 TICKS
80 DELAY ((OLD_TICKS%-2)*5) SECONDS
15 DELAY (1ST_SHIFT_LNG%) HOURS
40 DELAY 1 HOURS
In each of the above examples, when the DELAY statement
executes, the task will be suspended at that point for the specified
amount of time and then be eligible to run when the time interval
expires. At that time, the task begins execution at the line following
the DELAY statement.