Allen-Bradley DeviceNet 1761-NET-DNI, Руководство пользователя, Страница: 75 / 101

1761-6.5
Chapter
7
Application Examples
All examples are for illustration and information purposes only. Because of
the many variables and requirements associated with any particular
installation, Rockwell Automation cannot assume responsibility or liability
for the actual use based on the examples and diagrams.
MicroLogix as I/O on DeviceNet
MicroLogix controllers are incapable of being true slave I/O products. But,
they are capable of behaving like slave I/O and more by adding logic (user
program). This example turns a MicroLogix controller into an I/O block on
DeviceNet. The MicroLogix input data is sent up to the DeviceNet master
as input data, and the DeviceNet master output data is sent to the
MicroLogix outputs.
The example logic is a user program that monitors the communications link
between the MicroLogix and the DeviceNet master and makes sure it is
operational. If problems occur with the communications link, the
MicroLogix controller turns off the outputs. If the connection is restored,
the controller recovers and behaves like an I/O block.
If you would prefer to have the MicroLogix maintain the outputs when a
communications fault is detected, remove or disable some of the logic in
this application (review the comments for each rung to determine which
logic to remove). Or, if you prefer to have the controller behave differently
on a communications fault, simply add the corresponding logic that you
require.
AB Parts