A Controller is a host running a program which reads and writes the Process Values used to control an automated process. The control is usually done in cycles consisting of reading the Input Process Value, processing the Input, calculating the Output, and finally writing the Output Process Value.

A Device is a stand-alone unit exchanging cyclic data with a Controller. Devices are usually configured by the Controller and may also generate acyclic data like alarms or diagnostic information. A Device may consist of several modules and Submodules.

Remote IO is defined in this specification as accessing the Input Telegram data and the Output Telegram data of a PN Submodule from a remote host without interfering or interacting with cyclic data transfer.

A RIO Channel comprises all Function Blocks, Functions and Variables used for processing of an analog or digital electric signal.

A RIO Input Channel comprises all Function Blocks, Functions and Variables used for processing of an analog or digital electric input signal. Typically, the RIO Input Channel generates an Input Process Value from an electric signal.

A RIO Output Channel comprises all Function Blocks, Functions and Variables used for processing of an analog or digital electric output signal. Typically, a RIO Output Channel is used to transfer an Output Process Value to an electric signal. In addition, RIO Output Channels may process a Readback Value.

A RIO Channel Group is an aggregation of RIO Channels.

Input is the data transferred from a monitored electrical sensor signal to the Controller.

Output is the data transferred from the Controller to a remote-controlled actuator signal.

A Transducer comprises all Functions used for the conversion of an electric signal into a digital representation and vice versa.

An Input Transducer comprises all Functions used for the conversion of an electric signal into a digital representation.

An Output Transducer comprises all Functions used for the conversion of a digital signal representation into an electric signal. As an option, an Output Transducer in addition can also convert the electric output signal back into a digital Readback Value representation.

The Readback Value is the result of feeding the electric signal back into the RIO Output Channel within an Output Transducer.

A Physical Value is the digital representation of the electrical signal or the physical value measured/controlled by the attached sensor/actor.

A Function Block comprises all Functions used for the conversion of the Physical Value into the Process Value and vice versa.

The Process Value are all data variables which are intended to be part of cyclic data transfer with a Controller.

An Input Process Value contains the Input data used by a Controller.

An Output Process Value contains a Controller’s Output data to an automated process.

A Telegram represents the cyclic data of one PN Submodule. A Telegram consists at least of one Input Telegram or of one Output Telegram or of both.

An Input Telegram represents the cyclic Input data of one PN Submodule. An Input Telegram consists of Signals.

An Output Telegram represents the cyclic Output data of one PN Submodule. An Output Telegram consists of Signals.

Signals are components of a Telegram. A Signal maps to a Variable in the Application Information Model.

A PN Submodule is the consumer or the provider of one Telegram and the addressable endpoint for PROFINET access.