Rockwell Automation GMLC Reference Manual - Manual (Page 359)

Publication GMLC-5.2 - November 1999
322 I/O and Event Blocks
Input event actions are fast because the event action block (connected to
the top (true) node of the Watch Control block) is completely evaluated
when the Watch Control block executes and, is ready for instant response
when the input event occurs. Therefore, any variables used in the event
action block are evaluated once, immediately when the Watch Control
block executes. The event action block should not itself use any
expressions that depend on the occurrence of the input event.
Disarm Input Event/Action
The Watch Control block with Disarm type and Input Event/Action class
selected cancels an input event set up by a previous Watch Control block
with Enable Event/Action selected, that has not yet executed.
On Watch
Use the On Watch block to:
•
Pause the program until the watch position event, or the registration
event, occurs on the selected axis.
• Monitor a previously configured position or registration event, and
branch program flow to the top (true) node if the event has occurred
or to the bottom (false) node if the event has not occurred.
The On Watch block resides on the Main Palette.
Wait for Position Event
The Wait for Position Event type pauses the program until the watch
position event for the selected axis occurs. The On Watch block with Wait
for Position Event selected executes only if a watch position event has
previously been set up for the selected axis, by a Watch Control block
with Arm type and Watch Position class selected.
If this is input type
is selected:
An:
Dedicated Axis menu lets you select the desired physical axis.
SLC Signal Event menu lets you select the desired event.