Rockwell Automation Publication 1769-UM011H-EN-P - April 2012 53
Communicate over Networks Chapter 4
The 1769-L32C and 1769-L35CR controllers support 100 connections.
However, the built-in ControlNet port only supports 32 communication
connections. With these controllers, the number of end-node connections they
effectively support depends on the connection’s NUT and RPI.
You can use all 32 communication connections on the built-in ControlNet port.
However, we recommend that you leave some connections available for tasks
such as going online and unscheduled network traffic.
DeviceNet Communication
The DeviceNet network uses the Common Industrial Protocol (CIP) to provide
the control, configuration, and data collection capabilities for industrial devices.
The DeviceNet network uses the proven Controller Area Network (CAN)
technology, which lowers installation costs and decreases installation time and
costly downtime.
A DeviceNet network provides access to the intelligence present in your devices
by letting you connect devices directly to plant-floor controllers without having
to hard wire each device into an I/O module.
NUT RPI Supported ControlNet Communication Connections
(1)
(1) For each NUT/RPI combination, the number of connections supported is listed in a range. The lower number is the number of
connections we recommend you make to maintain reasonable ControlNet port CPU utilization rates. The higher number is the
maximum number of connections possible for that NUT/RPI combination.
2 ms 2 ms 0...1
3 ms 3 ms 1...2
5 ms 5 ms 3...4
10 ms 10 ms 6...9
14 ms 14 ms 10...12
5 ms 20 ms 12...16
4 ms 64 ms 31
Table 8 - CompactLogix DeviceNet Communication Interfaces
If your application Select
· Communicates with other DeviceNet devices
· Uses the controller as a master or slave on DeviceNet
· Uses a controller ControlNet, Ethernet or serial port for other communication
1769-SDN DeviceNet
scanner module
· Accesses remote Compact I/O over a DeviceNet network
· Sends remote I/O data for as many as 30 modules back to scanner or controller
1769-ADN DeviceNet
adapter module
(1)
(1) This table specifically describes using the 1769-ADN module to access remote Compact I/O over DeviceNet. However, CompactLogix
controllers can access other Allen-Bradley remote I/O over DeviceNet. In those cases, you must select the appropriate interface. For
example, if accessing remote POINT I/O modules, you must select the 1734-ADN.