GE PACSystems RX3i

Chapter 3. Configuration
60 PACSystems* RX3i & RSTi-EP PROFINET IO-Controller User Manual GFK-2571N
I/O Scan Set: The scan set for the PROFINET Controller defaults to scan set 1. Scan sets are defined in the
CPU’s Scan Sets tab. The valid range is 1 through 32; the default value is 1. Refer to the PACSystems RX7i and
RX3i CPU Reference Manual, GFK-2222, for a discussion of CPU scan sets.
The embedded PROFINET Controllers and the PNC001 behave the same as far as this parameter is concerned.
Critical Network Ports: The default critical network port setting for all PROFINET Controller ports is
False. Setting one or more network ports on the PROFINET Controller as a critical network port
provides for triggering a CPU redundancy role switch when the last of all of the critical network port
links associated with that PROFINET Controller are lost (disconnected). Basically, when the last
critical network port is disconnected from its network, a diagnostic fault is logged by the PROFINET
Controller. In a redundancy system, where the PROFINET Controller is controlling redundant devices,
this results in a fatal IOC Software Fault and a Hot Standby CPU redundancy role switch with the CPU
placed into Stop/Fault mode.
When using the critical network ports feature, the following PROFINET speeds are strongly
recommended:
PROFINET Network Speed
Recommended Network Type
100 Mbps
Copper and/or Fiber based networks
1000 Mbps
Fiber based networks ONLY.
Network ports 3 and 4 support fiber based networks via the SFP interface
Copper-based networks are not recommended at 1000 Mbps due to the extremely slow link down
detection associated with both fixed and SFP-based copper ports at this network speed. Using
copper-based networks at 1000 Mbps may result in the loss of I/O Devices when the last critical
network port is disconnected from the network. For this reason, the PROFINET Controller has a built-
in feature that forces any Cu port (fixed or Cu SFP) that is configured as a critical port to 100M.
Note: Critical network ports are allowed in simplex systems. However, the logging of the diagnostic fault,
when the last of the critical network ports is disconnected, does not invoke any role switch, and does
not place the CPU in Stop/Fault mode.