Emerson PACSystems RX3i, User Manual

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RSTI-EP PROFINET I/O Controller User Manual Section 1
GFK-2571R May 2021
Introduction 19
1.6.6 One RX3i CPU with Four Controllers on Separate
Networks
Figure 11 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 255 IO-Devices are allowed, spread across the four networks. Up to
128 IO Devices can be controlled by any given PROFINET Controller.
Note that multiple PNC001 modules in the same rack are not synchronized; that is, no two
PNC001 modules are guaranteed to power up at the same time. PNC001 configuration
differences (SFPs, etc.) can also cause variations in PNC001 power-up times.
If two (or more) PNC001 modules are in a main rack and devices owned by one PNC001 are
routed through the switch on a different PNC001 in the same rack, devices may show a Loss
of Device fault followed by an Addition of Device fault during RX3i power-up because the
first PNC001 can power up before the second PNC001 has enabled its Ethernet switch,
causing the Loss of Device. Then when the second PNC001 powers up, the device will show
an Addition of Device fault, which is to be expected under these circumstances. Devices will
function normally once added.
Figure 11: RX3i System with four PNC001 modules and four Daisy-Chain PROFINET
LANs
As in the other examples, other Emerson IO-Devices can be substituted for the VersaMax
PROFINET Scanners.