Allen-Bradley 1756-IF8I, Руководство пользователя

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Rockwell Automation Publication 1756-UM540E-EN-P - December 2017 27
Analog I/O Module Features Chapter 2
Module Inhibiting
This feature suspends the connection between an owner-controller and a
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.
•
A controller owns a module and has downloaded configuration to it. Data
is being exchanged over the connection between the devices.
In this case, when you 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 need to use module inhibiting:
•
Multiple controllers own an analog input module. A configuration change
is required. You must make the change in the program in all controllers. In
this case, complete the following tasks.
a. Inhibit the module.
b. Change configuration in all controllers.
c. Uninhibit the module.
•
You want to upgrade the module. We recommend that you complete the
following tasks.
a. Inhibit the module.
b. Perform the upgrade.
c. Uninhibit the module.
•
The program includes a module that you do not physically possess and you
do not want the controller to continually look for a module that does not
exist.
Inhibit the module until it physically resides in the proper slot. To see
where to inhibit a module connection, see page 130 .
IMPORTANT
Whenever you inhibit an output module, it enters 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 states of the outputs go to
zero (0.0) during Program mode, whenever that module is inhibited, the
outputs go to zero (0.0).