Profinet Communications - Emerson PACSystems RX3i User Manual

RSTI-EP PROFINET I/O Controller User Manual
GFK-2571R
A PROFINET network can include three types of devices:
PROFINET IO-Controller
PROFINET IO-Device
PROFINET IO-Supervisor
4.1.1

PROFINET Communications

Communications on a PACSystems PROFINET network use the standard PROFINET
communications described in this section.
Application Relationships
Before an PACSystems PROFINET IO-Controller can exchange data with a PROFINET IO-
Device, an Application Relationship (connection) must be established between the devices.
The PACSystems PROFINET IO-Controller automatically sets up the correct number and
types of Application Relationship and Communication Relationship channels (see below)
based on its PAC Machine Edition configuration. Usually, only one Application Relationship
is established per IO Device.
Communication Relationships within an Application Relationship
Within each Application Relationship, the PACSystems 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
Figure 89 represents an Application Relationship between a PACSystems controller with a
PNC001 module and an IO-Device. In the example below, the IO Device consists of a
VersaMax PNS with VersaMax I/O modules, but the same principles apply for all IO-
Controllers and IO-Devices.
PROFINET System Operation
In an RX3i or RSTi-EP system, the CPU operates as an IO-
Controller. This may be done via the embedded PROFINET
feature of certain CPUs (refer to Section 0) or via a rack-
mounted IC695PNC001. It is a controlling device that is
associated with one or more PROFINET IO Devices.
A PROFINET IO-Device is a distributed I/O Device that is
coupled to a PROFINET IO-Controller via PROFINET.
An IO-Supervisor can be a programming device, a computer,
or an HMI device. The PROFINET IO-Supervisor is typically used
for commissioning or diagnostics.
Section 4
May 2021
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