SIMATIC ET 200M Overview 

  • Modular I/O system with IP20 degree of protection, particularly suitable for user-specific and complex automation tasks
  • Consists of a PROFIBUS DP or PROFINET interface module IM 153, up to 8 or 12 I/O modules of the S7-300 automation system (structure with bus connection or with active bus modules), and a power supply if applicable
  • Can be expanded with S7-300 automation system signal, communication and function modules
  • Applicable Ex analog input or output modules with HART optimize the ET 200M for use in process engineering
  • Can be used in redundant systems (S7-400H, S7-400F/FH)
  • Modules can be replaced during operation (hot swapping) with the bus modules active
  • Transmission rates up to 12 Mbps
  • Ex approval to Cat. 3 for Zone 2 acc. to ATEX 100 a
  • Fail-safe digital in/outputs as well as analog inputs for safety-oriented signal processing in accordance with PROFIsafe
  • Supports modules with expanded user data, e.g. HART modules with HART minor variables

SIMATIC ET 200M Design

The ET 200M modular I/O station comprises:

  • One IM 153 interface
  • Up to 12 I/O modules of the S7-300 automation system and
  • If required, one power supply.

There are no slot rules for the I/O modules. Any combination is permissible.

The ET 200M is connected via an interface module IM 153 to PROFIBUS DP or PROFINET. A connection to PROFIBUS DP using fiber-optic technology is additionally possible by means of additional optical link modules (OLM) or the optical bus terminal (OBT).

Depending on the quantity structure of the interface module (IM), different numbers and types of I/O modules can be inserted.

The full address space of the ET 200M can only be used with a suitable master.

IM 153-1 (Standard)

IM 153-2 (High Feature)


  • PROFIBUS DP standard slave, DP V1 slave with expanded functionality
  • PROFIBUS DP standard DP V1 slave with full S7 functionality for FM/CP
  • Redundancy through 2 x IM 153-2
  • Time stamp function and time-of-day synchronization
  • Routing of parameter settings to intelligent field devices (e.g. HART)
  • Isochronous mode
  • Configuration changes in RUN in the non-redundant system
  • Identification functions
  • Firmware update via bus

Address volume

128 bytes for inputs and 128 bytes for outputs each

244 bytes for inputs and 244 bytes for outputs each

Modules that can be used

SM; simple, non-parameterizable CPs and FMs

All SM/FM/CP/F modules without restriction

IM153-4 PN (Standard)

IM 153-4 PN (High Feature)


  • Up to 12 modules can be plugged-in
  • Integrated 2-port switch
  • Module replacement possible without PG (LLDP); optional: Saving the IP address and name on MMC
  • Shared Device on up to two IO Controllers
  • Media redundancy (MRP)
  • Isochronous real-time communication
  • IRT option “high performance”
  • Up to 12 modules can be plugged-in
  • Integrated 2-port switch
  • Module replacement possible without PG (LLDP); optional: Saving the IP address and name on MMC
  • Shared Device on up to two IO Controllers
  • Media redundancy (MRP)
  • Isochronous real-time communication
  • IRT option “high performance”
  • F modules (PROFIsafe)
  • Connection to S7-400 H CPUs with system redundancy

Address volume

192 bytes for inputs and 192 bytes for outputs each

672-byte inputs (for expanded HART user data)
192-byte outputs

Modules that can be used

SM; simple, non-parameterizable CPs and FMs

All SM/FM/CP/F modules without restriction

Configuration using bus connectors

Easy assembly using SIMATIC S7-300 bus connectors makes ET 200M flexible and service-friendly:

  • Module assembly;
    simply locate the modules on the mounting rail, pivot them and screw them down.
  • Integral backplane bus;
    the backplane bus is integrated into the modules. The modules are connected through bus connectors that are plugged into the back of the housings.
Assembly using active bus modulesSIMATIC ET 200M

The active bus modules allow reaction-free module replacement during operation:

  • Time-saving module replacement;
    operation is not interrupted on module replacement, it continues with the remaining modules. When the new module is inserted, it is automatically brought into operation again. When an S7-400 is used as a master, swapping of a distributed module is handled in the same manner as swapping of a central module. The relevant interrupt is generated in the CPU. For all other DP standard masters, a signal is sent to the master via DP diagnostics. With an S7-300 as master, hot swapping of modules is not supported.

Various modules are available for assembling the ET 200M that are mounted on a special mounting rail.

  • BM PS/IM bus module to hold the power supply and IM 153
  • Bus module BM IM 153/IM 153 for receiving two IM 153-2 modules for redundant operation (PROFIBUS only)
  • BM 2×40 bus module to hold 2 I/O modules of 40 mm in width
  • BM 1×80 bus module to hold 1 I/O module of 80 mm in width

To achieve the specified thread length, an explosion-proof partition is available as spare part; it can be inserted between two bus modules.

  • Easy assembly;
    the bus modules are pivoted in the mounting rail, arranged end-to-end and fixed using side connectors. The modules can then be inserted in the bus modules and screwed down so that they contact the bus module connector. Connectors of unused slots must be protected with backplane bus covers. A bus module cover must be plugged into the side of the last bus module.
Power supply

For ET 200M, single-phase power supplies are available with 2 A, 5 A and 10 A as special variants.

SIMATIC ET 200M Function

How it works

The user program of the automation system can access the inputs/outputs of the modular ET 200M I/O devices as well as the inputs/outputs of the central controller.

Communication over the bus system is fully handled by the master interface in the central controller and by the IM 153 interface.

The diagnostics functions verify the proper operation of the ET 200M.

The ET 200M can diagnose:

  • Module errors
  • Short-circuits (outputs)
  • Bus faults, i.e. incorrect data transmission
  • 24 V DC load voltage supply
  • Hot-swapping of I/O modules

The diagnostics data is evaluated as follows:

  • Decentralized, with diagnostics LEDs on the ET 200M
  • Centrally, in the central module (CPU) of the programmable controller.
Configuration and parameterization PROFIBUS

Configuration message frame

Parameter assignment frame


15 bytes + 5 bytes per S7-300 I/O module

10 bytes + 20 bytes per programmable S7-300 I/O module

Calculation of the required message frame length for the configuration and parameterization message frames

The DP master must provide the required amount of configuration and parameterization data. A few masters offer a shorter configuration and parameterization message frame length. For example, the maximum lengths of the configuration and parameterization message frames in the S5-95U/DP are 32 bytes each. This means in this example that a maximum of 3 modules can be plugged into the ET 200M, where one of them may be parameterizable.

When connecting the device to master modules which have not been configured with COM PROFIBUS or STEP 7 (operated on master modules of other manufacturers), a fixed pre-allocated GSD file may be created by COM PROFIBUS as of version 3. This is then loaded into the configuration tool of the other vendor and can be used for simple configuration of the station.

This allows use of the convenient plain text parameterization of COM PROFIBUS, eliminating the hexadecimal code entries in the configuration tool of the vendor.

A suitable master is required to use the full addressing range of the IM 153.

SIMATIC ET 200M Technical specifications

General technical data ET 200M

Cables and connections

Screw and spring-loaded connections in permanent wiring

Degree of protection


Ambient temperature on vertical wall (preferred mounting position)

  • with horizontal assembly

0 to +60 °C

  • with other assembly

0 to +40 °C

Relative humidity

5 to 95% (RH stress level 2 according to IEC 1131-2)

Atmospheric pressure

795 to 1080 hPa

Mechanical stress

  • Vibrations

IEC 68, parts 2 – 6:
10 – 57 Hz (const.amplitude 0.075 mm) 57 – 150 Hz (constant acceleration 1 g)

  • Shock

IEC 68, parts 2 – 27
half-sine, 15 g, 11 ms