Rockwell Automation Logix5000 Controllers I/O and Tag Data Programming Manual - Manual (Page 55)

Chapter 3
Force I/O
Use a force to override data that your logic either uses or produces. For example,
use forces to:
• Test and debug your logic.
• Check wiring to an output device.
• Temporarily keep your process functioning when an input device has failed.
Use forces only as a temporary measure. They are not intended to be a permanent
part of your application.
When you use forces, take these precautions.
ATTENTION: Forcing can cause unexpected machine motion that could injure personnel. Before you use a force,
determine how the force affects 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.
− Enabling SFC forces causes your machine or process to go to a different state or phase.
− Removing forces may still leave forces in the enabled state.
− If forces are enabled and you install a force, the new force immediately takes effect.
Enable forces
You must enable forces for a force to take effect. You can only enable and disable
forces at the controller level.
• You can enable I/O forces and SFC forces separately or at the same time.
• You cannot enable or disable forces for a specific module, tag collection, or
tag element.
Important: If you download a project that has forces enabled, the application prompts you to enable or disable forces
after the download completes.
When forces are in effect (enabled), a appears next to the forced element.
Introduction
Precautions
Rock well Automati on Publication 1756- PM004E -EN-P - October 2014 55