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Entry type: FAQ Entry ID: 102325771, Entry date: 01/19/2022

Which IO controllers and IO devices support the following functions in STEP 7 (TIA Portal): IRT, prioritized startup, MRP, MRPD, PROFIenergy, Shared device, MSI/MSO, I device, clock-synchronized mode, system redundancy and option handling?

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An overview shows which PROFINET functions you can configure in STEP 7 (TIA Portal) for the PROFINET IO controllers and IO devices.

In STEP 7 (TIA Portal) you can configure the above-mentioned PROFINET functions for the following PROFINET IO controllers.

 Login required  102325771_IO-Controller_PROFINET_functions_TIAPortal_mit_SIMOTION_en.xlsx (50,0 KB)

In STEP 7 (TIA Portal) you can configure the above-mentioned PROFINET functions for the following PROFINET IO devices.

 Login required  102325771_IO-Device_PROFINET_functions_TIAPortal_en.xlsx (35,6 KB)

Entry ID 49311792 
gives you an overview of the PROFINET IO controllers and IO devices of SIMOTION and SINAMICS that support the above-mentioned PROFINET functions.

Isochronous real-time communication (IRT)

Synchronized transmission procedure for cyclic exchange of IRT data between PROFINET devices. There is a bandwidth reserved for the IRT data in the transmitter clock. The reserved bandwidth guarantees that the IRT data can be transmitted at reserved, clock-synchronized intervals even when the network is otherwise heavily loaded (with TCP/IP communication or additional real-time communication, for example).

Prioritized startup

Prioritized startup is the PROFINET functionality for accelerating the startup of an IO device in a PROFINET IO system with RT and IRT communication.

The function cuts the time needed by the appropriately configured IO devices to get back into the cyclic user data communication in the cases below:

  • After return of power supply
  • After return of station
  • After enabling of IO devices

Media Redundancy Protocol (MRP)

Medium redundancy is a function for ensuring the availability of networks and plants. Redundant transmission paths (ring topology) ensure that when one transmission path fails an alternative path is made available.

Media Redundancy with Planned Duplication (MRPD)

With the MRP extension "Media Redundancy with Planned Duplication" (MRPD) you achieve media redundancy with short update times (together with IRT).
MRPD is based on IRT with "high performance" and MRP. To achieve media redundancy with short update times the PROFINET devices in the ring send their data in both directions. The devices receive this data at both ring ports, which eliminates ring reconfiguration time. As with MRP, the redundancy manager prevents circling data messages.


Function for saving power in the process, during idle times, for example, through temporary switch-off of the encoder and load supply in the potential group via standard PROFIenergy commands.

More information about PROFIenergy is available in the manuals ready for downloading in the Entry IDs below.

ManualDescriptionEntry ID
SIMATIC PROFINET System DescriptionGeneral information about PROFIenergy


SIMATIC S7-300 with PROFINET InterfacePROFINET IO controller or IO device with PROFIenergy


SIMATIC System Software for S7-300/S7-400
Volume 1 and Volume 2
Send and receive (PROFIenergy) data records
  • With the SFB73 "RCVREC" you receive the (PROFIenergy) data records in the I device from the higher-level IO controller.
  • With SFB74 "PRVREC" you make the (PROFIenergy) data records in the I device available to the higher-level IO controller.


SIMATIC HMI Comfort PanelsControl of the backlight of the operator panel with PROFIenergy


SIMATIC ET 200S: Power module PM-ESwitch-off of the potential group by means of PROFIenergy


SENTRON PAC3200 / PAC4200Incorporation of the SENTRON PAC multifunctional measuring device in PROFINET and PROFIenergy with the SENTRON SWITCHED ETHERNET PROFINET module


SIRIUS Motor starter M200D
PROFIenergy with motor starter M200D


ET 200S motor starter, fail-safe motor starter, safety engineering
  • PROFIenergy with DPV1 Starter
  • Switch-off of the motor and measurement of the current motor current with PROFIenergy


ET 200pro motor starterPROFIenergy with motor starter
ET 200pro


Table 1

Shared Device

IO device that makes its data available to multiple IO controllers.

Module-internal Shared Input / Shared Output (MSI / MSO)

The Module-internal Shared Input (MSI) function allows an input module to make its input data available to up to four IO controllers. Each IO controller has read access on the same channels.
The Module-internal Shared Output (MSO) function allows an output module to make its output data available to up to four IO controllers. One IO controller has write access to the channels of the output module. In addition, up to three IO controllers have read access to the channels.

I Device

The "I Device" (intelligent IO device) function of a CPU permits you to exchange data deterministically with an IO controller and thus use the CPU as an intelligent processing unit, for example. As IO device the I device is connected to a "higher-level" IO controller.
The processing is ensured by the user program in the CPU. The process values captured in a central or remote IO are preprocessed by the user program and made available to a higher-level station over the IO device interface of the CPU or CP.

On a PROFINET interface, an I device can also be an IO controller in addition to its role as IO device, depending on the configuration.
In this way the I device can be part of a higher-level IO system via its PROFINET interface and establish a lower-level IO system as IO controller.
An I device can also be used as a shared device.

Clock-synchronized mode for process data

Process data, transmission cycle via PROFINET IO and user program are synchronized with each other to achieve the highest deterministics. The input and output data of distributed IOs in the plant is captured and output simultaneously. The equidistant PROFINET IO cycle is the clock for this.

System redundancy

Sytsem redundancy is the connection of IO devices via PROFINET with a communication connection between each IO device and each of the two fault-tolerant CPUs. The communication connection can be set up using any topological interconnection.

Contrary to a one-sided connection of IO devices, the failure of a CPU does not result in the failure of the IO devices connected with this CPU.

Configuration control (option handling)

With option handling in the network you can add complete stations, extend or change PROFINET networks with additional engineering effort. Here, also via the target IP address on the S7-1500, lower-level PROFINET devices are automatically given the correct network parameters (automatic address changing).
Central and distributed option handling (configuration control) enables you to prepare the structure of a station / IO device for future extensions and changes. In this way, complex automation projects only have to be configured once for the maximum configuration. Following that, different options can be defined and flexibly selected as required.

Further Information
Entry ID 44383954 gives you an overview of the IO controllers and IO devices that support the following functions in STEP 7 V5.x:

  • IRT
  • Prioritized startup
  • MRP
  • MRPD
  • PROFIenergy
  • Shared Device
  • I Device
  • Clock-synchronized mode
  • System redundancy
  • Option handling

The manual SIMATIC PROFINET PROFINET with STEP 7 V16 provides information about the above-mentioned PROFINET functions.

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