Rockwell Automation 1756-XXXX ControlLogix Analog I/O Modules - Manual (Page 47)

Publication 1756-UM009C-EN-P - December 2010 47
ControlLogix Analog I/O Module Features Chapter 3
Module Inhibiting
Module inhibiting lets you indefinitely suspend a connection between an
owner-controller and an analog I/O module. This process can occur in either
of the following ways:
• You write configuration for an I/O module but inhibit the module to
prevent it from communicating with the owner-controller. In this case,
the owner does not establish a connection and configuration is not sent
to the module until the connection is uninhibited.
• In your application, a controller already owns a module and has
downloaded configuration to the module and is currently exchanging
data over the connection between the devices. In this case, you can
inhibit the module and the owner-controller behaves as if the
connection to the module does not exist.
The following examples are instances where you may need to use module
inhibiting:
• Multiple controllers own the same analog input module. A change is
required in the module’s configuration; however, the change must be
made to the program in all controllers. In this case, you can:
a. Inhibit the module.
b. Change configuration in all controllers.
c. Uninhibit the module.
• You want to FLASH upgrade an analog I/O module. We recommend
you:
a. Inhibit the module.
b. Perform the upgrade.
c. Uninhibit the module.
• You are using a program that includes a module that you do not
physically possess yet, but you do not want the controller to continually
look for a module that does not exist yet. In this case, you can inhibit the
module in your program until it physically resides in the proper slot.
IMPORTANT
Whenever you inhibit an output module, it enters the Program
mode and all outputs change to the state configured for the
Program mode. For example, if an output module is configured
so that the state of the outputs go to zero (0) during Program
mode, whenever that module is inhibited, the outputs will go
to zero (0).