Marathon Computer UNIPRO V3.5 - Manual (Page 153)

MMI Product Documentation
Unipro 3.5 Process Control 1 Aug. 1997
The operation of a limit statement after the following
OPCODEs is described in more detail below:
E (EVENT) (INPUT) - A limit statement here will
cause the program to wait
for the specified event
INPUT (normally event
numbers 8-15) to switch to
the specified state (ON OR
OFF, 1 OR 0), before
proceeding. If this does not
occur within the specified
limit time, a limit time-out
alarm will occur.
Note: The event INPUT must be
held in the trip state for at least 30
seconds to make sure that the
Programmer will acknowledge it.
Thus, a momentary push button
could not be used as an event
INPUT unless some type of
latching scheme is employed.
If a limit statement is not used, the
program may wait indefinitely.