Communication is at the core of the Allen Bradley ControlLogix PLC platform. The following networks are available for a ControlLogix rack.
• EtherNet/IP
• ControlNet
• DeviceNet
• DH+
• Modbus
You can configure your system for information exchange between a range of devices
and computing platforms and operating systems.
EtherNet/IP Network
Ethernet Industrial Protocol (EtherNet/IP) is an open industrial networking standard that supports both real-time I/O messaging and message exchange. It is a high speed network and as no established schedule. Ethernet tends to be used as a communication link between the PLC and HMI/SCADA systems.
The Ethernet network can also be used to monitor and program PLC‘s on the network using the RSLogix programming products.
ControlNet Network.
The ControlNet network is an open, state-of-the-art control network that meets the demands of real-time, high-throughput applications. The ControlNet network uses the proven Common Industrial Protocol (CIP) to combine the functionality of an I/O network and a peer-to-peer network providing high-speed performance for both functions. The ControlNet network gives you deterministic, repeatable transfers of all mission-critical control data in addition to supporting transfers of non-time-critical data.
ControlNet tends to be used for remote I/O applications and PLC to PLC communications. Due to the fact that ControlNet is deterministic a schedule for the network must be created. The schedule is created with the RSNetWorx software package.
A ControlNet network can also be used in a non scheduled way to monitor and program PLC ‘s on the network using the RSLogix 5000 programmer.
Each Ethernet device will require an IP address, and each ControlNet device will require a node number between 0 to 99. A schedule also needs to be created for the ControlNet network this is created with the program RSNetWorx for ControlNet. This is explained in the ControlNet section of the manual
DeviceNet Network.
The DeviceNet network is an open low-level network that provides connections between simple industrial devices (such as sensors and actuators) and higher-level devices (such as PLC controllers and computers). The DeviceNet network uses the proven Common Industrial Protocol (CIP) to provide the control, configure, and data collection capabilities for industrial devices. The DeviceNet network is a flexible network that works with devices from multiple vendors.
DeviceNet is commonly used to communicate to plant I/O devices and variable speed drives.
A configuration file is required by the DeviceNet module this is created and downloaded with the RSNetWorx for DeviceNet software package
