Rockwell Automation 1761-NET-DNI DeviceNet Interface (DNI) - Manual (Page 69)

69 Publication 1761-UM005B-EN-P - October 2006
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 the
DeviceNet Network 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 the DeviceNet network. 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.