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PACSystems* RX3i PROFINET Controller Manual
– December 2011
GFK-2571A
1
One RX3i CPU with Four Controllers on Separate Networks
This example shows a system with one RX3i CPU node containing the maximum of four RX3i
PROFINET Controllers, with each PROFINET Controller connected to a different network. In this
architecture, up to 128 IO-Devices are allowed, spread across the four networks. Up to 64 IO-
Devices can be controlled by any given PROFINET Controller.
Note that multiple PNCs in the same rack are not synchronized such that all PNCs are guaranteed to
power up at the same time. PNC configuration differences (SFPs, etc.) can cause variations in PNC
power up times.
If two (or more) PNCs are in a main rack and devices owned by one PNC are routed thru the
switch on a different PNC in the same rack, devices may show a Loss of Device
fault followed by
an
Addition of Device
fault
during RX3i powerup because the
first PNC can power up
before the
second
PNC has enabled its Ethernet switch
,
causing
the Loss of Device.
Then when the
second
PNC
p
owers up, the device will show a Addition of Device fault
.
Devices will function normally
once added.
IO-Device
IO LAN 1
IO LAN 2
IO LAN 3
IO LAN 4
RX3i CPU Node
w/ four PNCs
IO-Device
IO-Device
IO-Device
IO-Device
IO-Device
IO-Device
IO-Device
NOTE:
Daisy-chain shown for clarity.
A star or ring topology is
preferred.
As in the other examples, third-party IO-Devices could be substituted for the VersaMax PROFINET
Scanners.