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Entry type: Product note Entry ID: 109792919, Entry date: 02/01/2021

Sales and delivery release for firmware V2.1.8 for LOGO! CMR2020 (6GK7142-7BX00-0AX0) and LOGO! CMR2040 (6GK7142-7EX00-0AX0) including download

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The new firmware V2.1.8 for the LOGO! CMR2020 and LOGO! CMR2040 modules has been released and is now available for download free of charge. The modules are scheduled for delivery starting in 03/2021 with the new V2.1.8 firmware.

1. Product description

Firmware version V2.1.8 is the successor of version V2.1.7 and contains function extensions for support of LOGO! CMR communication with the new LOGO! BM 8.3. The firmware also includes general improvements and optimizations. 

The update to V2.1.8 is necessary for all customers who are using a LOGO! CMR and want to use it to monitor and control a LOGO! BM with the new version 8.3. Due to a security-related change in LOGO! BM 8.3, only an encrypted connection can be used between LOGO! CMR and LOGO! BM as of this version to exchange the process data. This is supported with FW V2.1.8 of the LOGO! CMR.

Please observe the notes on parallel access from the LOGO! CMR and LSC/LWE to a LOGO! BM 8.3 and on using the newly introduced SMS commands in the updated manual.


The following improvements and optimizations are also being released with firmware V2.1.8:


  • Process communication: The LOGO! CMR can now be started and stopped via the WBM. In stopped state, there is no connection to the LOGO! BM and none of the assignments are processed.
  • MSTATUS?: Introduction of a new SMS to receive the current operating state of the LOGO! CMR.
  • MSTATUS=RUN/STOP: Introduction of a new SMS to change the current operating state of the LOGO! CMR via SMS.
  • ECC (Elliptic Curve Cryptography): Activation of the ECC encryption method for faster encryption. This affects all SSL encryptions.
  • Correction of a sporadic SMS send error caused by an incorrect AT+CRES setting for the LOGO! CMR2040 when using SIM cards with PIN.
  • GPS: Negative altitudes were not displayed correctly in the WBM. The display has been corrected with V2.1.8.
  • As of LOGO! BM 8.3 and LWE V1.1, access to user-defined Web pages of the LOGO! BM via the LOGO! CMR2020 and CMR2040 is possible without restrictions.
    Note: The described restrictions of the Web page access in the following FAQ refer to the LOGO! BM < 8.3: 109763463 


It is generally recommended to always use the most recent firmware versions.


2. Ordering data 

Product name

Order number






3. Firmware V2.1.8 download

Please note the following before you start the update:

  • The LOGO! CMR with firmware V2.x that are already in use can be updated with a firmware update via the Web Based Management (WBM). A LOGO! CMR with version V1.x must first be upgraded to a version V2.x < V2.1.8.
  • FW V2.1.8 is backward compatible and can also be operated with LOGO! BM devices < 8.3.
  • A downgrade from FW V2.1.8 to V2.0.12, V2.1.4, V2.1.5 and V2.1.7 is possible for modules with hardware product version 1.
  • A downgrade from FW V2.1.8 to V2.0.12 is not possible for modules with hardware product version 2.
  • A downgrade from FW V2.1.8 to V2.1.7, V2.1.5 or V2.1.4 is possible for modules with hardware product version 2.
  • Compatibility with Config files of V2.0.12, V2.1.4, V2.1.5 and V2.1.7 is guaranteed. When upgrading the firmware, the stored configuration is adapted to the new version. Old settings are retained, and new functions are preset with default values. Configurations that were created with V2.0.12, V2.1.4, V2.1.5 or V2.1.7 can also be loaded to V2.1.8.


Third-party software – license conditions and copyright notes

You can find the copyright information for third-party software contained in this product, particularly open source software, as well as applicable license conditions of such third-party software in the Readme OSS file. 

Special note for resellers

The information and the license conditions in the readme OSS file must be passed on to the purchasing party to avoid license infringements by the reseller or purchasing party. 

Download Readme OSS:  Registrierung notwendig  LOGO_CMR_2_1_170908_ReadMe.html (668.1 KB) 

You can download FW V2.1.8 here:

 Registrierung notwendig  CMR1427BX00EX00_V2.1.8_OSS.zip (1.5 MB)



4. Previous version

7 Oct. 2019: Firmware update V2.1.7 for LOGO! CMR2020 (6GK7142-7BX00-0AX0) and LOGO! CMR2040 (6GK7142-7EX00-0AX0): 109772048 


5. Hardware version

The two LOGO! CMRs are delivered with hardware product version 2 (V2.0).

Security information
In order to protect technical infrastructures, systems, machines and networks against cyber threats, it is necessary to implement – and continuously maintain – a holistic, state-of-the-art IT security concept. Siemens’ products and solutions constitute one element of such a concept. For more information about cyber security, please visit
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