Submodules
A submodule represents a data‑holding unit inside a module. It defines I/O channels, configuration access points, and diagnostic endpoints used by the controller.
To be included in the PROFINET device structure, a submodule must be assigned to a subslot.
Currently, a submodule cannot be assigned to multiple subslots.
Submodules data types
Each submodule can provide:
Cyclic I/O data in both input and/or output direction
Acyclic parameter records
Alarm and diagnostic endpoints (Currently not supported)
Valid submodules without full data sets
A submodule is still valid even if it has:
No cyclic data (for parameter-only or diagnostic structures)
No acyclic data (for pure I/O structures)
When to use submodules
Use submodules to group related channels or functions so that the device remains clear and easy to interpret in engineering tools.
Organize your submodules
To keep the PROFINET device structure readable:
Group related channels or functions into the same submodule.
Use separate submodules when functions differ or diagnostics must be isolated.
Cyclic data submodules
Cyclic data is always closest associated with a submodule. It is used for time‑critical I/O in the PROFINET device model.
Each submodule can provide:
One cyclic input data set
One cyclic output data set
Use cyclic data for time‑critical I/O:
Status values
Control signals
High‑frequency communication
A submodule can also contain no cyclic data.
This is appropriate when the submodule represents:
Parameter access points (PAPs)
Diagnostic structures
Logical or virtual functions without I/O
Cyclic data sets are pulled from the Host Interface configuration (your device application).
These data sets must exist before they can be assignment to a submodule.
Acyclic data submodules
Acyclic parameter records always belong to a submodule.
Unlike cyclic data, acyclic data does not require a predefined data set.
Parameters are mapped directly as acyclic records by assigning a record index.
A submodule can expose:
Configuration parameters
Diagnostic parameters
Maintenance‑related information
These parameters are accessed acyclically by the controller or engineering tool when needed, not during every PROFINET network cycle.
Key characteristics:
No cyclic data set is required.
Parameters are individually mapped using record indexes.
Records are exchanged only on demand (not time‑critical).
Individual parameters can be directly mapped as acyclic parameter records.
Virtual submodules
A virtual submodule has no physical hardware.
It acts as a logical placeholder for configuration or parameter access.
Use virtual submodules to represent:
Parameter‑only access
Logical or software‑based functions
A clear separation between configuration functions and I/O functions
Rules for virtual submodules:
Anybus Studio automatically sets the plugging rule of a virtual submodule to .
If a module contains only one virtual submodule, engineering tools display it as a single‑level module (no visible subslot hierarchy).