GE IC695PNC001 User Manual page 71

Communication Relationships within an Application Relationship
Within each Application Relationship, the RX3i PROFINET IO-Controller establishes the following
types of Communication Relationships (CRs):

Record Data CRs – always the first to be established within an Application Relationship. Record
Data Communication Relationships are used for non-real-time transfers of data records such as
startup parameter data, diagnostics data, identification data, and configuration data.

IO CRs – used for the real-time, cyclic transfer of I/O data

Alarm CR – used for real-time, acyclic transfer of alarms and events
The illustration below represents an Application Relationship between a PACSystems RX3i
controller with a PNC module and an IO-Device. In this example, the IO-Device is a VersaMax PNS
with VersaMax I/O modules, but the same principles apply for all IO-Controllers and IO-Devices.
RX3i CPU with PROFINET Controller
GFK-2571A
Application Relationship
Record Data Communication Relationship
I/O Data Communication Relationship
Alarm Communication Relationship
Chapter 4 System Operation
IO-Device, such as
VersaMax PROFINET Scanner
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