Rockwell Automation Publication 1756-UM013B-EN-P - October 2019
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Digital Safety I/O Module Operation in a Control System
Chapter 1
Connection Over an EtherNet/IP Network
When you configure a remote safety module, you must configure the
Connection over EtherNet/IP parameter in the configuration for the remote
adapter that connects the I/O modules to the network. The configuration choice
dictates how input data is transmitted over the network.
The 1756 ControlLogix digital safety I/O modules use one of the following
methods to transmit data:
• Multicast - Data is sent to all network devices.
• Unicast - Data is sent to one or more controllers depending on module
configuration.
Unicast is the default setting.
Input Module Operation
Logix 5000 controllers do not poll the safety input modules for input data.
The data exchange process between the input modules and the controller differs
based on whether the module is a local I/O module or remote I/O module.
Local 1756 ControlLogix Digital Safety Input Modules
Local 1756 ControlLogix digital safety input modules broadcast their input data,
that is, channel and status data, to the system backplane at the time that is defined
in the RPI.
At the RPI, the following events occur.
1.
The local input module scans its channels for input data.
2.
The module sends the data to the system backplane.
3.
The controller receives the data immediately.
IMPORTANT
1756 ControlLogix digital safety input modules cannot trigger events.
Summary of Contents for 1756 Series
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