The ON TIMER seconds clause defines a set of instructions that
must be executed at regular intervals. This interaction block can be used, for example,
to check if a message has arrived in a queue, and needs to be processed.
The parameter of ON TIMER must be an integer literal or variable. If
the value is zero, the dialog timeout is disabled.
It is not recommended to use the
ON TIMER trigger with a short timeout
period, such as 1 or 2 seconds. The purpose of this trigger is to give the control back to the
program after a reasonable period of time, such as 10, 20 or 60
seconds.
ON TIMER 30
CALL check_for_messages()
Important: The timer value is taken into account when the dialog initializes its
internal data structures. If you use a program variable instead of an integer constant,
a change of the variable has no effect if the change takes place after the
dialog has initialized. If you what to change the value of the timeout variable, it must
be done before the dialog block.