Section 6: Exchange Cycling Data; Exchange Cycling Data - Emerson Bettis RTS Installation, Operation And Maintenance Manual

Section 6: Exchange Cycling Data

September 2023
Section 6: Exchange Cycling Data
PROFINET IO uses the concept of a cyclic process data image. Each PROFINET IO
network Controller or Device has an image of input and output data. Each image is
updated via communication partner images using periodic Ethernet frames. These
frames are sent at intervals configured by the engineering tool. The frames contain
the I/O data and the data status associated with it.
Moreover, each frame contains a "global" frame data status field which can be
used e.g., to mark the whole frame as invalid. PROFINET IO organizes the cyclic
data in a Provider Consumer model, i.e., an I/O data consumer exists for every I/O
data provider. Both indicate their current state to each other in several frames.
These states are:
•
•
The IOPS indicates whether the associated data is valid (good) or invalid (bad). For
instance, a faulty submodule in a device will mark its input data as good or bad by
setting the IOPS. To indicate whether the data has been handled, the consumer
returns the IOCS to the provider. For instance, a Digital Analog Converter submodule
can use this status to indicate to the controller an output value that is outside the
range. With PROFINET IO, each submodule has its IO data and IO data states, i.e.
the IO data plus two IO data states are exchanged for every submodule used by
the IO-Controller. Regarding the Ethernet frame structure, the provider data state is
located directly behind the IO data and contains information on whether the IO data
is good and may be evaluated or not. The consumer state is sent in the opposite
direction in an other frame and contains information on whether the IO data can be
handled by the consumer.
8
The IO Provider State (IOPS)
The IO Consumer State (IOCS)
Installation, Operation and Maintenance Manual
FCIM-20054-EN Rev. 0

Exchange Cycling Data