WAGO-I/O-SYSTEM 750
Fieldbus Communication 135
750-375 PROFINET IO advanced Fieldbus Coupler
Manual
Version 1.1.0
"Communication Relationships" (AR) uniquely specify the data within the AR.
Multiple ARs from different IO controllers can be set up for one IO device.
11.2.5.3 Application and Communication Relationship (AR, CR)
The IO controller initiates an application relationship during system start-up. In
addition to general communication parameters, all data for device modeling is
loaded into the IO device. At the same time, the communication channels for
cyclic/acyclic data exchange (IO Data CR, Record Data CR), alarms (Alarm CR)
and multicast communication relationships (MCR) are set up.
Within an AR, communication relationships (CR) must be established for data
exchange. A unique communication channel between a consumer and provider is
specified.
11.2.6
System Start-Up
After power-on or reset, the IO controller initiates start-up of the PROFINET IO
system. From the user's perspective, the system start-up is completely
autonomous.
During system start-up, the IO controller uses the "connect frame" to initiate the
connection and transfers all data required to establish an AR and the required
CRs.
The data contains the relevant parameterization data, as well as the sequence,
process data traffic and monitoring time for system start-up.
The transmission frequency of the cyclic IO data is determined when configuring
the I/O controller.
At the same time, the cyclic IO data, alarms, exchange of acyclic read/write
services, expected modules/submodules and possibly required cross connections
between IO devices are also determined.
With specific "write frames", the IO controller parameterizes the configured
submodules that represent the data interface for the process.
When all parameters are loaded into the IO device, the IO controller signals
parameterization to be complete with the "DControl.req" frame
("EndOfParameterization").
The user software then creates the final data structures and updates the submodule
status.
When all data structures have been created in the IO device and the required tests
have been performed, the IO device sends a "CControl.req" to the IO controller to
indicate readiness for productive data exchange ("Application Ready"). From the
perspective of the IO device, communication has been established.
With acknowledgement from the IO controller to "Application Ready",
communication is established again from the perspective of the IO controller.
The IO device reports errors discovered during parameterization to the IO
controller.
After the first successful exchange of IO data the system start-up is complete.
