LOGO! Modular communication modules

Logikmodul LOGO!


Network project

Although LOGO! was mainly designed to replace conventional switching technology, the LOGO! family offers some interesting communication options. Due to the transition to the Ethernet port as standard programming interface, the current communication modules generally have a different method to connect to the basic units. In previous generations up to LOGO! 7, communication modules were connected via the LOGO! backplane bus and therefore took up address space in the process image of the inputs/outputs. In LOGO! 8, the connection is done via Ethernet. This means the entire address space of the inputs/outputs remains available for digital and analog signals.

Integrated communication

LOGO! Ethernet LAN Port

Ethernet opens up completely new communication options based on TCP/IP by using the SIMATIC S7 protocol:

  • LOGO! modules with each other

  • LOGO! with all SIMATIC S7 controllers

  • LOGO! with SIMATIC HMI devices

  • LOGO! with communication modules

As part of the transition to the Ethernet port as standard programming interface, the LOGO! PC cable is replaced with a standard Ethernet cable.
The new TDE is also connected via standard Ethernet cable.

All basic units with Ethernet port can be operated on WLAN via corresponding access points. This means they can be programmed, monitored and controlled remotely.

Integrated web server – it couldn’t be easier

The integrated web server in all LOGO! 8 basic units is used for monitoring and control the LOGO! via WLAN and the Internet.
The web server provides:

  • Simple configuration via mouse click

  • Compatibility with all conventional browsers, without the need for programming experience in HTML

  • Required view identical to the LOGO display or the TDE display

  • Operation of LOGO! 8 via smartphone, tablet or PC

  • Same look and feel as on the display of LOGO! 8 or the TDE

Easy step up steps:

  • open the message text function block, select the tickbox of the web server in the user program and transfer the program to the LOGO!

  • then allow access of the web server online via LOGO! Soft Comfort and protect it with a password

  • establish a WLAN connection of the LOGO! 8 via an access point

  • connect your smartphone, tablet or PC to the accesspoint and monitor or control your LOGO!

Communication options




• LOGO! <-> LOGO!
• LOGO! via WLAN
• LOGO! via Internet




• LOGO! Web server




You can increase the number of Ethernet ports with the LOGO! CSM.
This Ethernet 4-port switch allows to set up cost-efficient, small local Ethernet networks.

Communication via communication modules

The LOGO! family offers several communication modules for the communication with external system. The connection is done via the backplane bus up to generation LOGO! 7.
Between LOGO! 8 and communication modules the connection is done exclusively via Ethernet.

New with LOGO! 8 is SMS communication for alarming and remote control via cell phone using the LOGO! CMR module. It automatically sends out alarm messages via SMS.
The CMR can also read control commands from a SMS and transfer them to LOGO! 8.
The same module supports position detection and clock synchronisation via GPS, for example, for cost-effective container tracking and position reporting via SMS to a control center.
CMR can synchronize the time worldwide with LOGO! 8.
CSM is a Ethernet 4-port switch, that can be used to expand the number of Ethernet ports to set up small local Ethernet networks.

LOGO! Modular Communication modules




CMR 2020 / CMR 2040 (via Ethernet)




CSM 12/24V (in LOGO! 8 design, via Ethernet)




CSM 230V (in LOGO! 7 design, via Ethernet)




CMK 2000 (KNX via Ethernet)




KNX (via backplane bus)




AS-interface (via backplane bus)




LOGO! CMR communication module

The CMR (Communication Module Radio) for LOGO! 8 has 3 typical areas of application:
1. Communication with LOGO! 8 via SMS (GSM) for alarms, process monitoring and control directly from the mobile terminal unit
2. GPS position detection
3. Time synchronization of LOGO! 8 via NTP server or GPS

LOGO! CMR supports remote communication via the mobile network with LOGO! 8.
This means distributed plants can be monitored and controlled with SMS or alarm messages can be triggered from LOGO!.
Typical applications:

  • Fill level or temperature monitoring, alarms on limit violations

  • Change of setpoints

  • Control of blinds, lights, pumps or irrigation systems, etc. via SMS

  • LOGO! as control unit for clocks in church towers or schools and regular time synchronization

  • Container tracking: Position data and additional information, such as the current temperature values in a container, are queried from the LOGO! station via SMS and transmitted with the LOGO! CMR.

The CMR module offers the following features:

  • Configuration via integrated web interface

  • Up to 20 messages to different groups of recipients

  • Address book with 20 phone numbers

  • Query of specific process values, for example, meter readings, temperature, pressure, etc.

  • Changing of setpoints

  • Stand-alone operation possible

The hardware offers:

  • Slot for SIM card

  • Slot for micro SD card to save the configuration

  • Two integrated inputs and two integrated outputs

  • Connector for a GPS antenna

  • Connector for a GSM antenna

  • DIN rail or wall mounting

The CMR is available in two versions with the same functions.
The CMR 2020 module is suitable for GSM (2G) networks or UMTS (3G) networks.
With LOGO! CMR2040, LOGO! 8 is connected to the latest mobile communications standard of the 4th generation LTE (Long Term Evolution). A fallback function also permits use of the module for the UMTS and GPRS mobile communications standards via GSM.

GSM - Global System for Mobile Communications
UMTS - Universal Mobile Telecommunications System
GPRS - General Packet Radio Service
LTE - Long Term Evolution

Note: For use of the LOGO! CMR2020 and CMR2040 communication modules, country-specific mobile network approvals must be strictly observed:

A SIM card with cell phone contract is mandatory for SMS operation.
Sufficient coverage of the selected cellular service provider has to be checked at the operating site of the LOGO! / CMR module.

CSM Compact Switch Module

With the LOGO! CSM 230 and LOGO! CMS 12/24 compact switch modules, LOGO! 8 and LOGO! 7 units can be supplemented with additional Ethernet ports and Ethernet networks can be set up flexibly with 10/100 Mbps in line, tree, or star topology.

The design of the switch modules has been adapted to the LOGO! series for installation in building cabinets, enabling seamless and space-saving installation. One port can be accessed from the front without having to remove the covers. The unmanaged switches can either connect several logic modules to each other, or they offer connections for additional components such as control and monitoring devices, displays, or programming devices (PG). The advantage of unmanaged switches is plug and play, which means they can be used without in-depth IT expertise.

  • 4-port unmanaged switch

  • CSM 12/24 for 12/24 V DC supply voltage (housing design LOGO! 8)

  • CSM 230 for 230 V AC/DC supply voltage (housing design LOGO! 7)

  • Power supply via terminal strip connections

  • Diagnostics LEDs

Communication module CMK 2000, CM EIB/KNX

For communication in building automation CMK 2000 offers acces for LOGO! 8, while the CM EIB/KNX communication module are used for LOGO! 7 and LOGO! 6.

One LOGO! can thus be integrated into a KNX system as intelligent controller via the Konnex building bus system.
The CMK 2000 and CM EIB/KNX transform the typical PLC signals (binary or analog) into KNX telegrams for communication with other KNX actuators.
In the opposite direction, they read the KNX telegrams and set the corresponding signal levels for the LOGO!.
Signals that are acquired via the standard LOGO! inputs are thus efficiently linked with signals from the KNX system (telegrams) by means of logical functions or timing elements. Analog signals can be monitored for limits or setpoints and corresponding manipulated variables for actuators can be output on the LOGO! or the KNX.
This opens new opportunities for Applications like:
Monitoring, access control, heating, ventilation and air conditioning (hvac), lighting, blind control , irrigation up to pump control.
The integrated clock of LOGO! can be used for synchronization with other KNX stations.
The LOGO! can be master or slave of the synchronization.

With the communication module LOGO! CMK 2000 the number of channels that can be used is independent from the configuration level of the LOGO!, i.e. the full LOGO! configuration can be used for KNX. The module communicates via Ethernet with LOGO! 8:

  • Max. 24 DI, 20 DQ, 8 AI and 8 AQ

  • Date and time can be synchronized via KNX

  • beside digital and analog inputs and outputs process values inside the application program are available as communication objects on the KNX

  • Dimming actuators and shutter/blind actuators on the KNX can be controlled in a system-compliant way

  • 50 configurable communication objects are available, the user defines the communication direction and data format himself

With CM EIB/KNX the number of channels that can be used for the KNX communication depend on the configuration level of the LOGO!. The signals of the process image that are not used by the LOGO! hardware are used as virtual inputs via the CM EIB/KNX.

  • Max. 16 DI, 12 DQ, 8 AI and 2AQ (8AQ via multiplexer) as interface to the KNX

  • Date and time can be synchronized via KNX

  • Digital and analog inputs and outputs are available as communication objects on the KNX

  • Dimming actuators and shutter/blind actuators on the KNX can be controlled in a system-compliant way

CM AS-Interface slave communication module

LOGO! 7 and LOGO! 6 can be integrated as intelligent slave into an AS-Interface system with the AS-Interface module.
The interface module provides four digital inputs and four digital outputs on the AS-interface.
As intelligent slave, LOGO! processes signals from standard sensors, controls the actuators independently and can receive instructions from the AS-i master via AS-i bus signals and pass on status signals such as error messages to the master. In case of a bus failure, the LOGO! can continue to control its sub-process independently. The expansion module takes up 4 digital inputs and 4 digital outputs of the LOGO! process image.
These virtual I/Os are used just like standard inputs/outputs inside the LOGO! program.

Technical Data

Communication modules with Ethernet connection

CMK 2000

Communication Module KNX (CMK)



Communication Module Radio (CMR)

Note: For use of the LOGO! CMR2020 and CMR2040 communication modules, country-specific mobile network approvals must be strictly observed:

CSM 12/24

CSM 230

Compact Switch Module (CSM)

Communication modules with connection via backplane bus


CM AS-interface (Slave)

Communication Module (CM)

* mapped on LOGO! inputs/outputs