Allen-Bradley DeviceNet 1761-NET-DNI, User Manual, Page: 77 / 101

1761-6.5
Application Examples 7-3
Example Ladder Logic
The ladder program example is used to monitor the integrity of the
communications link with the DNI. If something happens and
communications are lost (cable is cut or removed, DNI loses power or
faults, etc.) this logic detects that condition. The user can program the
controller to respond to a loss of communications, if desired.
The example ladder logic shown below is available for download from
http://www.ab.com/micrologix. The sample is compatible with RSLogix
500 programming software. The file name is DNI I-O.RSS and contains two
programs:
DNI MicroLogix Heartbeat Logic, DNI I-O.RSS Ladder 2 - Main Program
•
Monitors the communications link for integrity. This is considered to be
part of the Heartbeat logic associated with the DNI.
DNI - COS (change of state) I/O Messaging, DNI I-O.RSS Ladder 6 - COS ML DNI
•
Moves the Input and Output data inside the controller, for correct
operation with the DNI.
AB Parts