Resolving Duplicate Ip Addresses; I/O Scanning - Emerson PACSystems RX3i User Manual

RSTI-EP PROFINET I/O Controller User Manual
GFK-2571R
• Note that whenever a second PROFINET Controller with an identical IP Address to the
active PROFINET Controller is connected to the network, the second controller will not
succeed in entering the network.
When the IP conflict is resolved, the PROFINET IO-Controller:
• logs a Duplicate IP Address Resolved fault for itself,
• attempts to re-connect all configured PROFINET IO-Devices,
• logs an Addition of Device fault for each connected PROFINET IO-Device to indicate that
device is back online.
Note:
4.2.3

Resolving Duplicate IP Addresses

Whenever an IP Address conflict exists, IP-based network communication with the device(s)
may be disrupted. The IP Address conflict should be resolved by disconnecting one of the
offending devices from the network or assigning each a unique address. The Duplicate IP
Address Detected fault lists the MAC address of the offending devices in bytes 8 – 13 and 14
– 19 of the Fault Extra Data. The Discovery and Configuration Protocol (DCP) tool in PAC
Machine Edition may be useful to identify PROFINET devices on the network with conflicting
IP Addresses.
4.3

I/O Scanning

In the PACSystems PROFINET network, multiple I/O cycles run asynchronously and
independently. Figure 91 illustrates typical cycles in a system with an PACSystems CPU with
a PROFINET Controller, and PNS modules used as the head-end in IO Devices. Cycles may be
different for third-party devices.
Figure 91: Diagram of Multiple Asynchronous I/O Scans
PROFINET System Operation
Power cycling a rack that has a PNC001 with the same IP Address as another node on the
network will result in two Duplicate IP Address Detected faults in the I/O Fault Table. This
is normal behavior that occurs because the PROFINET Controller retains IP parameters
through a power cycle and attempts to exist on the network before receiving a new
configuration from the CPU. The first fault occurs before the PNC001 receives the new
configuration and the second fault occurs after the PNC001 receives its new
configuration. Both faults result in the PNC001 not attempting to connect to the
network.
Section 4
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