GE IC695PNC001 User Manual page 18

1
Systems with One RX3i CPU and Two PROFINET Controllers
Both examples in this section show systems with one RX3i CPU that has two PROFINET Controller
modules. The PROFINET network can serve up to 63 IO-Devices (ring topology) or 64 IO-Devices
(in star topology).
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
powers up, the device will show a Addition of Device fault. Devices will function normally once
added.
In the following example, both PROFINET Controllers are connected to the same network.
RX3i CPU Node with
2 PROFINET Controllers
IO-Device 1
IO-Device 2
PACSystems* RX3i PROFINET Controller Manual – December 2011
1-12
IO LAN 1
IO LAN 1
NOTE:
Daisy-chain shown for clarity.
A star or ring topology
is preferred.
IO LAN 1
IO-Device 3
IO-Device 4
GFK-2571A