AMX NETLINX PROGRAMMING LANGUAGE, Manual

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Language Elements
36 NetLinx Programming Language Reference Guide
Waits
Wait instructions allow delayed execution of one or more program statements. When a wait statement is
executed, it is added to a list of currently active wait requests and the program continues running.
Naming Waits
Supplying a unique name in the wait statement allows the wait to be identified for purposes of canceling,
pausing, or restarting the wait request. The name must not conflict with previously defined constants,
variables, buffers, subroutines, or functions. Unlike other NetLinx identifiers, wait names may contain
spaces.
If a wait instruction that uses a name currently in the wait list is encountered, the new wait instruction is
thrown away so as not to conflict with the one currently in progress. If this feature is not desired, the
current wait must be canceled before processing the new request. For information, refer to the
Canceling
Waits section on page 38.
Types of Waits
Types of Wait statements include:
Timed Waits have an associated parameter that indicates the amount of time that must elapse
before the associated wait instruction(s) are to be executed.
Conditional Waits require that a specified condition be met before the instructions are
executed.
Timed Conditional Waits have a timeout parameter; if the condition is not met before the
specified time elapses, the wait request is cancelled.
Types of Waits
Timed Waits Syntax:
WAIT time ['<name>']
{
(* wait statements *)
}
Parameters:
•
time
: A constant or variable indicating the wait time. Time is expressed in 1/
10th second units. The statement below specifies a wait time of 5 seconds
for the wait named
FIRST WAIT
.
•
<name>
: The name to assign to the wait. This name must be a literal string.
The wait name is optional, although unless a wait is named it cannot be
individually cancelled, paused, or restarted.
If greater precision is required, the time parameter can be expressed as a dec-
imal fraction, for example 0.1 to specify a wait time of 1/100th of a second. The
range is from 0.1 to 0.9.
WAIT 50 'FIRST WAIT'
{
(* wait statements *)
}
Continued