Allen-Bradley 1756-L65 ControlLogix 5565, Programming Manual

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Rockwell Automation Publication 1756-PM004D-EN-P - September 2012 61
Force I/O Chapter 3
·
If a produced tag is forced, you cannot make it Constant.
Force an Input Value
Forcing an input or consumed tag:
·
overrides the value regardless of the value of the physical device or
produced tag.
·
does not affect the value received by other controllers monitoring that
input or produced tag.
Force an Output Value
Forcing an output or produced tag overrides the logic for the physical device or
other controller. Other controllers monitoring that output module in a
listen-only capacity will also see the forced value.
Add an I/O Force To override an input value, output value, produced tag, or consumed tag, use an
I/O force.
1. What is the state of the I/O Forces status indicator?
2. Open the routine that contains the tag that you want to force.
3.
Right-click the tag and choose
Monitor
.
If necessary, expand the tag to show the value that you want to force (that
is, BOOL value of a DINT tag).
ATTENTION: Forcing can cause unexpected machine motion that could
injure personnel. Before you use a force, determine how the force will
effect your machine or process and keep personnel away from the
machine area.
– Enabling I/O forces causes input, output, produced, or consumed values to change.
– If forces are enabled and you install a force, the new force immediately takes effect.
If Then note
Off No I/O forces currently exist.
Flashing No I/O forces are active. But at least one force already exists in your project. When you enable
I/O forces,
all existing I/O forces will also take effect.
Solid I/O forces are enabled (active). When you install (add) a force, it immediately takes effect.