Operations Of The Profinet Controller In The Pacsystems System; Duplicate Profinet Io-Device Ip Address - GE PACSystems RX3i User Manual

Chapter 4. PROFINET System Operation
4.2 Operations of the PROFINET Controller in the
PACSystems System
The PROFINET IO-Controller in the PACSystems controller system performs the following operations:
•
Consumes PROFINET IO-Device configuration from the CPU and transfers it to the IO-Devices over
the PROFINET network.
•
Consumes input data from each PROFINET IO-Device and makes that data available to the CPU
during the CPU's input scan.
•
Produces the output data that it receives from the CPU during the CPU's output scan to each
PROFINET IO-Device.
•
Receives PROFINET alarms and diagnostics from PROFINET IO-Devices and converts them to a
PACSystems format.
•
Maintains a Local Log Table of its own alarms and the diagnostic information it receives. It also
forwards some of the information to the CPU as I/O or Controller Faults.
•
Automatically converts between the little-endian data format recognized by the CPU and the big-
endian format used for PROFINET communications.
•
Checks for duplicate IP Addresses as described below.
4.2.1

Duplicate PROFINET IO-Device IP Address

The PROFINET IO-Controller will detect an IP Address conflict between a device that it is configured to
communicate with and another device in two situations:
•
First, duplicates are detected when the PROFINET IO-Controller is trying to initially establish
communications with the configured PROFINET IO-Device. During the connection sequence, the PROFINET
IO-Controller queries the network to see whether any other node has the same IP Address as the
configured device.
•
Second, duplicates are detected whenever a network device announces its presence
the IP Address of that device is identical to that of a PROFINET IO-Device that the PROFINET Controller is
currently communicating with.
In both cases, the PACSystems PROFINET IO-Controller attempts to establish or maintain the connection and
logs a Duplicate IP Address Detected fault for the device. The PROFINET IO-Controller then periodically queries
the network for resolution of the IP Address conflict. If the IP Address conflict is resolved, the PROFINET IO-
Controller logs a Duplicate IP Address Resolved fault for the device.
5 The PROFINET Controller uses the ARP protocol to detect duplicate IP addresses. Devices that issue a gratuitous ARP to
announce their presence on the network are detected.
90 PACSystems* RX3i & RSTi-EP PROFINET IO-Controller User Manual
5 on the network and
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